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A chemical equation is a written symbolic representation of a chemical reaction (The symbols are the elemental letter or letters representing that element). The reactant chemical(s) are given on the left-hand side and the product...

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Interactive periodic table showing names, electrons, and oxidation states. Visualize trends, 3D orbitals, isotopes, and mix compounds. Fully descriptive writeups.

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It's important to know how to use a periodic table. The periodic table organizes the elements in a way that allows you to predict element properties and chemical reactions, even if you don't know anything about an element except what you see on the table. Here's a look at the information you can find on a standard periodic table of the elements and how to use these facts:

Periodic Table Organization

Elements are listed in order of increasing atomic number. (Note Mendeleev's original table organized element by order of increasing atomic weight.)

Elements are grouped according to periodic properties or trends. On a colored periodic table, the element groups usually are different colors from each other. The main element groups are: alkali metals, alkaline earth metals, transition metals, basic metals, rare earth metals (lanthanides and actinides), metalloids (semimetals), nonmetals, halogens, and noble gases.

A row of the periodic table is called an element period. A period indicates the highest energy level occupied by the electrons of that element at its ground state.

A column of the periodic table is called an element group. Members of an element group have the same number of valence electrons.

The two rows separated from the main body of the table are the rare earth elements, which consist of the lanthanides and actinides. These elements may be considered special transition metals.

How to Read an Element Cell

The one- or two-letter symbol is the element's symbol. Usually, the symbol includes the first letter of an element's name, although there are some exceptions. For example, H is the element symbol for hydrogen. Br is the element symbol for bromine. Yet, Hg is the symbol for mercury. Element symbols are recognized and used internationally, even though countries may use different names for elements.

Some periodic tables list each element's full name.

The integer number is the element atomic number. This is the number of protons in each atom of that element. For example, each bromine atom has 35 protons. Atoms of different elements may have the same number of electrons and neutrons, but never the same number of protons.

The decimal number is the element's atomic weight. The atomic weight is a weighted average of the mass of the isotopes of that element. Atomic weight is given in atomic mass units (amu). You can also consider the number as the grams per mole of each element. For example, one mole of bromine atoms would have a mass of 79.904 grams.

How to Use a Periodic Table to See Periodic Table Trends

The table is organized to display trends or periodicity of element properties:

Atomic Radius: one-half the distance between the nuclei of two atoms that are just touching each other.

Ionization Energy: energy needed to completely remove an electron from an atom or ion in the gas phase.

Electron Affinity: measure of an atom's ability to accept an electron.

Electronegativity: measure of an atom's ability to form a chemical bond

The periodic table organizes elements to show trends in ionization energy, atomic radius, electron affinity, and electronegativity.

Summary of Periodic Table Trends

Moving Left → Right Across a Row of the Periodic Table

Atomic Radius Decreases

Ionization Energy Increases

Electron Affinity Generally Increases (except Noble Gas Electron Affinity Near Zero)

Electronegativity Increases

Moving Top → Bottom Down a Column of the Periodic Table

Atomic Radius Increases

Ionization Energy Decreases

Electron Affinity Generally Decreases

Electronegativity Decreases

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It's important to know how to use a periodic table. The periodic table organizes the elements in a way that allows you to predict element properties and chemical reactions, even if you don't know anything about an element except what you see on the table.

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What is an element? How many elements are there?

An element is a substance that is made entirely from one type of atom. For example, the element hydrogen is made from atoms containing a single proton and a single electron. If you change the number of protons an atom has, you change the type of element it is.

If you had very, very good eyes and could look at the atoms in a sample of hydrogen, you would notice that most of the hydrogen atoms would have no neutrons, some of them would have one neutron and a few of them would have two neutrons. These different versions of hydrogen are called isotopes. All isotopes of a particular element have the same number of protons, but have a different number of neutrons. If you change the number of neutrons an atom has, you make an isotope of that element.

Currently, scientists know of 118 different elements. Some, like gold, silver, copper and carbon, have been known for thousands of years. Others, such as meitnerium, darmstadtium and ununquadium, have only recently been created by scientists. All known elements are arranged on a chart called the Periodic Table of Elements.

Related Pages:
All About Atoms What is an atom? What are atoms made of? What is the difference between atoms and elements? Who discovered the elements? The Periodic Table of Elements

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What is an element? How many elements are there? An element is a substance that is made entirely from one type of atom. For example, the element hydrogen is made from atoms containing a single proton and a single electron. If you change the number of protons an atom has, you change the type of element it is.

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Isotopes

An isotope is made up of atoms of the same element that have the same atomic mass. Different isotopes of an element arise from atoms with differing numbers of neutrons. Uses of isotopes. Average atomic masses from natural abundances: The weighted-average calculation.

Atomic number, mass number and isotopes

Musical accompaniment for these lecture notes.

The atomic number of an element (symbolized as Z) is the number of protons in the nuclei of its atoms. The mass number ( A) is the total number of nucleons (neutrons and protons). An isotope is made up of atoms of the same element (which by definition have a characteristic and fixed atomic number) that also have the same mass number. Different isotopes of an element arise from atoms with differing numbers of neutrons. Because of this, chemists need a way to represent specific isotopes of an element. Isotopes of an element have the same atomic number, but different mass numbers. The atomic number, when represented along with the symbol of an element, is shown as a leading subscript. The mass number is shown as a leading superscript. Since the element symbol implies an atomic number, the latter is often dropped, and an isotope as commonly represented textually with just the mass number and the element symbol (for example ¹⁴C or ¹⁸ O).

In the periodic table, the elements, represented as their symbols, are arranged in a particular pattern that reflects (as we will see) a regularity, or periodicity in their properties. Typically in the table, the element symbol is contained within its own small box, along with other information including the atomic number and the average atomic mass. The average atomic mass of an element represents the averages of its naturally occurring isotopic masses weighted according to their natural abundance. The formula for calculation of average atomic mass and illustration of its use is presented below.

How do the isotopic forms of an element differ from one another, physically and chemically? Isotopes are defined by their subatomic particle composition, which we will think of as a physical property. The chemistry of an element is determined by, in a general sense, the number of valence electrons its atoms possess. The number of valence electrons associated with a neutral atom is in turn determined by the number protons in the nucleus. Thus, two atomic nuclei could have the same number of protons, but different numbers of neutrons. Yet since the atoms they are part of would still have the same number of valence electrons, these two atoms would be chemically indistinguishable.*

Uses of isotopes

There are a wide variety of applications of isotopes in nuclear chemistry, medicine, biochemistry, anthropology, paleontology, and geology. Many such uses are based on the phenomenon of radioactivity, shown by some of the isotopes of many of the elements. Such radioactive isotopes are unstable, undergoing spontaneous nuclear decay processes at a rate determined by the half-life of the isotope. One example is the use of ¹⁴C - the isotope of carbon with six protons and eight neutrons, which has a half-life of 5730 years - as a basis for dating of materials derived from living organisms that are many thousands of years old. This technique, called radiocarbon dating, is used widely in geosciences and anthropology.

Average atomic masses from natural abundances: The weighted-average calculation

The atomic masses given in the periodic table represent weighted averages based on the natural abundances of the isotopes of a given element. The formula for a weighted average is

Here the x i's are the masses of the individual isotopes, and the w i's are the fractional abundances corresponding to the isotopes. Note that the weights must sum to 1 (equivalently the percent abundances must sum to 100%).

For example, chlorine exists in two isotopic forms, ³⁵Cl and ³⁷Cl. The mass of the ³⁵Cl isotope is 34.97 amu and that of ³⁷ Cl is 36.97 amu. The abundances are 75.77% and 24.23%, repectively. Therefore in this case, the weighted average becomes

wa = (0.7577)(34.97 amu) + (0.2423)(36.97 amu) = 35.45 amu

The result of this calculation is the atomic mass of chlorine that appears in the periodic table.

* Actually, since isotopes of an element differ in atomic mass, they can be subtly distinguished by differences in reaction rates, or in physical processes - such as rate of diffusion - affected by mass.

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An isotope is made up of atoms of the same element that have the same atomic mass. Different isotopes of an element arise from atoms with differing numbers of neutrons. Uses of isotopes. Average atomic masses from natural abundances: The weighted-average calculation. Atomic number, mass number and isotopes Musical accompaniment for these lecture notes.

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Of the three major subatomic particles, the negatively charged electron was first discovered by the English physicist Joseph Thomson in 1897.

As the structure of atoms was probed, it was realized that these low‐mass particles occurred in a large "cloud" around the tiny nucleus, which contained almost all the mass of the atom. A neutral atom has precisely equal numbers of protons (+) and electrons (-). Atoms with a charge imbalance are called ions. A positive ion has lost one or more electrons, whereas a negative ion has gained one or more electrons. Table 1 shows three different charge states for copper:

The chemical behavior of the various elements is influenced more by the charge of their ion than by any other intrinsic property. In the periodic table, elements in a column form analogous compounds because they have the same charge on their ions.

The halogens all tend to gain one electron, giving their ions a characteristic charge of -1. The alkali metals, on the other side of the periodic table, all readily lose one electron, so their ions possess a charge of +1. Charges are balanced in a compound with the number of alkali metal ions equal to the number of halogen ions; NaCl is such a compound. By contrast, consider the alkaline earths in the second column on the left side of the table. These elements are metals that form oxides that have an earthy texture and yield alkaline solutions. The alkaline earths have ions with a charge of +2. For one of them to form a compound with a halogen, twice as many halogen ions are needed to balance the +2 charge on the metal ions. Consequently, the correct chemical formula for strontium fluoride is SrF ₂.

Figure 1. The alkali metals form ions with a +1 charge; the alkaline earths, +2; and the halogens, -1.

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Of the three major subatomic particles, the negatively charged electron was first discovered by the English physicist Joseph Thomson in 1897. As the structure of atoms was probed, it was realized that these low‐mass particles occurred in a large "cloud" around the tiny nucleus, which contained almost all the mass of the atom.

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WHAT IS ATOMIC STRUCTURE?

All atoms are made of three smaller particles called protons, neutrons and electrons. The protons and neutrons clump together at the center of an atom and the electrons orbit far away. Atoms can be combined to form molecules through chemical reactions.
To better understand atomic structure...
WHAT IS ATOMIC STRUCTURE?. All atoms are made of three smaller particles called protons, neutrons and electrons. The protons and neutrons clump together at the center of an atom and the electrons orbit far away. Atoms can be combined to form molecules through chemical reactions. To better understand atomic structure...

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Atoms & Molecules | Reading Material | Grades 6-8

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Everything around us is made of atoms and molecules. Atoms are made from protons, neutrons and electrons. This printable reading page is made for middle school kids.

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Speciation can take place in two general ways. A single species may change over time into a new form that is different enough to be considered a new species. This process is known as anagenesis. More commonly, a species may become split into two groups that no longer share the same gene pool. This process is known as cladogenesis. There are several ways in which anagenesis and cladogenesis may take place. In all cases, reproductive isolation occurs.

Sympatric Speciation

Sympatric speciation occurs when populations of a species that share the same habitat become reproductively isolated from each other. This speciation phenomenon most commonly occurs through polyploidy, in which an offspring or group of offspring will be produced with twice the normal number of chromosomes. Where a normal individual has two copies of each chromosome (diploidy), these offspring may have four copies (tetraploidy). A tetraploid individual cannot mate with a diploid individual, creating reproductive isolation.

Sympatric speciation is rare. It occurs more often among plants than animals, since it is so much easier for plants to self-fertilize than it is for animals. A tetraploidy plant can fertilize itself and create offspring. For a tetraploidy animal to reproduce, it must find another animal of the same species but of opposite sex that has also randomly undergone polyploidy.

Allopatric Speciation

Allopatric speciation, the most common form of speciation, occurs when populations of a species become geographically isolated. When populations become separated, gene flow between them ceases. Over time, the populations may become genetically different in response to the natural selection imposed by their different environments. If the populations are relatively small, they may experience a founder effect: the populations may have contained different allelic frequencies when they were separated. Selection and genetic drift will act differently on these two different genetic backgrounds, creating genetic differences between the two new species.

Parapatric Speciation

Parapatric speciation is extremely rare. It occurs when populations are separated not by a geographical barrier, such as a body of water, but by an extreme change in habitat. While populations in these areas may interbreed, they often develop distinct characteristics and lifestyles. Reproductive isolation in these cases is not geographic but rather temporal or behavioral. For example, plants that live on boundaries between very distinct climates may flower at different times in response to their different environments, making them unable to interbreed.

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Speciation can take place in two general ways. A single species may change over time into a new form that is different enough to be considered a new species. This process is known as anagenesis. More commonly, a species may become split into two groups that no longer share the same gene pool.

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1. Variation: Individuals in the population must differ with respect to the trait in question. Without this variation, all individuals will have the same trait value and cannot be distinguished with respect to that trait.

2. Heritability: The variation found in the population must (at least partially) be heritable, e.g. transmitted from parent to offspring. If the variation in the trait was due entirely to the environment, for example, changes in the parent population would not affect the characteristics of the offspring population.

3. Differential Mortality: Finally, individuals must have a probability of survival that is a function of the value of the trait in question. If all individuals, regardless of there trait value, had an equal probability of survival and fecundity, no predictable change in the mean value of the population would occur.

Observe the effect of the presence and absence of these conditions to the right:

The trait in question here is the color of the individual. In this case selection acts against purple individuals and for green individuals.

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1. Variation: Individuals in the population must differ with respect to the trait in question. Without this variation, all individuals will have the same trait value and cannot be distinguished with respect to that trait. 2. Heritability: The variation found in the population must (at least partially) be heritable, e.g.

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#102 Artificial and natural selection

Artificial selection is a method used by humans to produce varieties of animals and plants which have an increased economic importance. People use selective breeding to produce new varieties of a species, so that certain desirable traits are represented in successive generations.

A variety is a type of a particular species that is different in some clear way from other varieties of that species. The different breeds of domestic dogs and large ears of maize corn are products of artificial selection.

Selective breeding of cows

Suppose you wanted a variety of cow that produced a lot of milk. This is what you could do:

choose or select the cows in your herd that produce the most milk

let only these cows reproduce

select the offspring that produce the most milk

let only these offspring reproduce

keep repeating the process of selection and breeding until you achieve your goal.

Natural selection is the process by which plants and animals that can adapt to changes in their environment are able to survive and reproduce while those that cannot adapt do not survive. It gives the greater chance of passing on of genes by the best adapted organisms.

Try this
Farmers have carried out artificial selection to improve the breeds of some animals. Some of the original breeds have become very rare and are in danger of becoming extinct.

a) Explain what is meant by artificial selection [ 2 marks]
b) i) Name one species which is in danger of extinction. [1 mark]
ii) Biologists are concerned that species of animals and plants should not become extinct. Why is it important to prevent the extinction of plant and animal species [2 marks]

Answer

a) A method used by humans to produce varieties of animals and plants which have an increased economic importance.
b) i) Any endangered species, such as panda, tiger, elephant, named whales species, named tuna species.
ii) Two point from:
- to maintain the gene pool
- to provide chemicals that may be useful in development of medicines
- the species may be an important part of a food chain
- rare species may provide tourism to supply poor communities with money.

Additional source: BBC Bitesize

Video: What is Natural Selection?

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Artificial selection is a method used by humans to produce varieties of animals and plants which have an increased economic importance. People use selective breeding to produce new varieties of a species, so that certain desirable traits are represented in successive generations.

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ecological succession | Definition & Facts

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Ecological succession: Ecological succession, the process by which the structure of a biological community evolves over time.

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Natural Disruptions to Ecosystems

You have learned that an ecosystem is a community of organisms that interact with each other and their environment. Ecosystems change over time. Sudden disruptions such as volcanoes, floods, or fires can affect which species will thrive in an environment. Other disruptions are caused by human activities. Some disruptions can be devastating for an individual species and may even cause an entire species to permanently disappear in a process called extinction. As species become extinct, the variety of species in the biosphere decreases, which decreases biodiversity, or the variety of life. Every organism plays an important role in the ecosystem to which it belongs. Whenever one species is removed, other species in the food chain are affected. These changes influence a community's biodiversity and can disrupt an entire ecosystem.

Wildfires

Fire is a common disruption to ecosystems that can be caused by nature or by human behavior. Natural wildfires can both help and harm an ecosystem. For example, wildfires kill many small animals and displace others that flee to safety. Animals looking to return after the fire will find their homes and much of their food supply destroyed. Also, bare soil that remains after a wildfire is particularly susceptible to soil erosion because the soil is no longer held in place by roots.

Wildfires can help an ecosystem by clearing out much of the dead and dying vegetation allowing surviving plants to benefit from increased light. Ash and charcoal left from burnt vegetation can help add nutrients to depleted soils. These nutrients provide a rich environment for surviving vegetation and sprouting seeds, allowing them to flourish. Eventually ecosystems rebound from fire disruption and are renewed with nutrient-rich soil and flourishing vegetation.

Flooding

Flooding can occur after a storm and may be disruptive to an ecosystem, depending on the extent of the flooding and how long the water stays. Flooding can result in saturated soils, or soils that are filled with water. Plant roots require oxygen, so saturated soils can kill plants by drowning the plant roots. Flooding may also cause water and nutrients to run off across land surfaces. Rushing water can cause soil to wash away, particularly bare soil. Burrows, dens, and nests can be destroyed, forcing surviving animals to relocate.

Some ecosystems, called flood plains, are made up of species that have adapted to occasional flooding. Flood plains are flat areas along rivers that flood when the river rises above its banks. The flooding deposits nutrient rich sediment along stream banks. Adaptations of flood-plain species allow them to thrive in their ecosystem.

Volcanic Eruptions

On May 18, 1980, an earthquake under Mount St. Helens contributed to a tremendous volcanic eruption. The north face of the mountain slid away in a huge avalanche, releasing a blast of superheated, rock-filled gas that ripped up the trees in its path. Subsequently, slower flows of gas and rock destroyed trees and living organisms in the soil. Mature forests were turned into ash covered wasteland. Since then, hardy plants have reappeared in the ash field. The plants attract herbivores that drop seeds from other plants in their dung. About three decades after the eruption, the forest began to regrow. The steady progression of species change and replacement in an ecosystem over time, as occurred after the eruption of Mount St. Helens, is called ecological succession.

Human Effects on Ecosystems

Humans impact the natural world more than any other species. Without limits on human activity, humans can damage the environment in many ways. As the human population grows, it requires more resources to keep its members healthy and comfortable. Each new family needs a place to live, food, water, clothing, medicine, and tools.

Habitat Destruction

Habitat destruction occurs when a habitat is removed and replaced with some other type of habitat. No matter how careful the plan, land used to grow crops or build houses is no longer suitable for some of the organisms that once lived there. As a result, the organisms living at the site must move or be destroyed. Habitat destruction is the most important reason species are threatened with extinction today. Habitat destruction can have harmful effects on humans, too. Scientists believe that some of the destruction caused by Hurricane Katrina in 2005 resulted from the removal of wetlands that would normally take up much of the regional floodwaters. Natural coastal ecosystems, including thick vegetation, may be able to buffer the coastline from hurricanes and other storms.

Introduced Species

Wherever humans go, they take animals, plants, and microorganisms with them. Tulips-as well as most crop plants and many other highly-valued garden plants-are not native to the United States but rather are introduced species. Introduced species are an important part of the economy and of society. Some introduced species, however, can be disruptive to an ecosystem. An introduced species that has negative effects in its new ecosystem is called an invasive species.

Invasive species can have serious effects on an ecosystem and on the human population. For example, a vine called kudzu was introduced to the southern United States as a way to control soil erosion. However, the kudzu spread rapidly, choking the roots of some plants and blocking light for other plants, effectively killing them and changing the ecosystem.

Overhunting

Throughout history, humans have hunted or killed animals for several reasons. They obtained food and necessary materials from animals and eliminated competition for crops and prey. They protected livestock by trapping or hunting animals such as wolves. Many species were driven to extinction by hunting thousands of years ago. As the human population grew, more and more species of animals were threatened with extinction from overhunting. Laws were passed to limit hunting and to ban the killing of endangered species. Nevertheless, poaching, or illegal hunting, continues to threaten many populations.

Pollution and Environmental Change

As you can see in the graph on the next page, the human population has grown exponentially over the last few centuries. This population growth was a result of increasing resources and new technology to feed and provide for the growing population. Human activities cause pollution-the release of harmful substances into the environment-including air pollution, water pollution, and the production of hazardous waste. Air pollution in the form of carbon dioxide has contributed to global warming.

One effect of today's heavy use of fossil fuels-including coal, oil, and gas-is air pollution. Air pollution includes noxious compounds and particulate matter. Air pollution can result in respiratory trouble and other human sickness.

!Human Population Growth]()

Sources of water pollution include the runoff of fertilizer from lawns and agricultural fields, as well as runoff from oil and other urban pollutants. Water pollution is also caused by oil spills, in addition to smoke from power plants. Fertilizers introduce excess nutrients and result in major changes in water ecosystems, including changing the pH of the water, causing algae blooms, and reducing the oxygen in the water. Rainwater can wash all pollutants on Earth's surface into rivers, lakes, and the ocean. Oil spills kill animals and can affect several different food webs. Air pollution can lead to water pollution by causing acid rain that can damage-and even kill-living things. Water pollution can also occur when people do not properly dispose of toxic household or industrial materials.

Global Climate Change

Climate change can involve global warming, a slow rise in Earth's average temperature. While global temperatures have changed over time, most scientists agree that the release of carbon dioxide into the air from the burning of fossil fuels contributes to this rise in temperature. An increasing rise in temperatures could affect ecosystems around the globe. For example, rising temperatures can speed up the melting of glaciers and ice caps disrupting or destroying habitats along shorelines as waters rise. Climate change can affect precipitation patterns resulting in droughts or floods. Climate change can also alter ecosystems as populations unable to survive warmer temperatures migrate to cooler regions.

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You have learned that an ecosystem is a community of organisms that interact with each other and their environment. Ecosystems change over time. Sudden disruptions such as volcanoes, floods, or fires can affect which species will thrive in an environment. Other disruptions are caused by human activities.

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Welcome to CK-12 Foundation | CK-12 Foundation

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Carrying capacity: Carrying capacity, the average population density or population size of a species below which its numbers tend to increase and above which its numbers tend to decrease because of shortages of resources. The carrying capacity is different for each species in a habitat because of that species'

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Last Updated on May 23, 2020 by Sagar Aryal

What is binary fission? (Definition)

Binary fission is a type of asexual reproduction where a single living cell or an organelle grows twice its size and then splits into two identical daughter cells, where each of these daughter cells has the potential to grow into the size of the original cell or organelle.

Binary fission differs from other types of fission in that; only two parts are formed from a single entity.

This form of reproduction is called asexual as the process doesn't involve the formation or fusion of gametes.

Because binary fission is a type of asexual reproduction, the daughter cells formed have the same genetic material as their parent cell.

Binary fission is the mode of reproduction in many prokaryotes including, archaea, cyanobacteria, eubacteria, and some eukaryotes like amoeba and Paramecium.

Some cell organelles like mitochondria also undergo cell division by the process of binary fission.

In order to remain viable and competitive, a bacterium must divide at the right time, in the right place, and must provide each offspring with a complete copy of its essential genetic material.

Steps/Process of Binary Fission

Binary fission in prokaryotes

Figure: Binary fission in prokaryotes. Image Source: Wikipedia.

Before binary fission, unlike human cells in which the genetic material is present inside a nucleus, the genetic material of the prokaryote (chromosomes) is present in a specialized region of the cell in the cytoplasm as a nucleoid.

The chromosomes then undergo replication starting from a point in the chromosome called, the origin of replication. The origin then divides, and as the replication continues, the two origins move towards opposite ends of the cell, pulling the chromosomes with them.

Once the replication is completed, different types of proteins working as cell division machinery assemble at the future division site (at the center of the cell).

One of the essential proteins in this process is the FtsZ protein which forms a ring-like structure at the center of the cell.

This process is essential to ensure that the division splits the cytoplasm and doesn't damage the genetic material.

Now, for the division of the cytoplasm, the membrane pinches inwards forming a septum (new cell wall) forms down the middle of the cell.

Finally, the septum divides itself to form two independent cells.

Crenarchaeota having neither a cell wall nor the FstZ protein, however, utilizes a primitive mechanism involving different proteins called the ESCRT-III system.

Binary fission in eukaryotes

Although most of the eukaryotes undergo sexual reproduction, some protozoans like amoeba reproduce by binary fission and cell division in some organelles within the eukaryotic cells occurs in a similar bacteria-like fashion.

The process of binary fission in these cells is the same as that of prokaryotes involving the FtsZ protein.

Cell organelles like mitochondria and chloroplasts divide by binary fission which gives the basis for the Endosymbiotic theory, which explains that the prokaryotes have evolved into the present-day mitochondria.

Types of binary fission

Binary fission is of four types based on the plane of division of the cytoplasm:

In this case, the division of cytoplasm (cytokinesis) can occur in any plane but is mostly perpendicular to the plane of division of chromosomes (karyokinesis).

This type occurs in organisms like an amoeba.

In transverse binary fission, cytokinesis occurs along the transverse axis of the cell.

This type of division occurs in ciliated protozoans like Paramecium.

A group of different organisms, including both prokaryotes and eukaryotes, divide by binary fission.

Most of the bacteria reproduce by this process. The process involves the division by utilizing the FtsZ protein, including chromosomal replication, chromosomal segregation, and cell splitting.

In protozoans like amoeba, Paramecium, Euglena, however, the process might differ in cell splitting and in how the cytoplasm divides.

Organisms that reproduce by binary fission include Bacillus subtilis, B. cereus, B. pumilus, Escherichia coli, Clostridium perfringens, Corynebacterium diphtheriae, Amoeba, Paramecium, Euglena, Ceratium, etc.

Here, the division of cytoplasm occurs along the longitudinal axis of the cell.

This type of division occurs in flagellates like Euglena.

The division of the cytoplasm, in this case, occurs obliquely (i.e. left and right oblique).

This type of division occurs in dinoflagellates like Ceratium.

Examples of organisms that use Binary Fission

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https://www.britannica.com/science/binary-fission

Binary Fission vs Mitosis

Occurrence
This occurs in prokaryotes and some eukaryotes.

This occurs only in eukaryotes.

Mechanism
In binary fission, spindle fibers are not formed.

In mitosis, the division is supported by the formation of spindle fibers.

Stages
Binary fission involves three stages, namely, chromosome replication, chromosomal segregation, and cytoplasm splitting.

Mitosis involves four stages; prophase, metaphase, anaphase, and telophase.

Product
This process results in the formation of two identical daughter cells, both with the same genetic content as the parent cell.

This process also results in the formation of two identical daughter cells, both with the same genetic content as the parent cell.

Function
Binary fission is a type of asexual reproduction.

Mitosis is involved in cell growth (numbers) in multicellular organisms.

References and Sources

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Binary Fission- definition, steps, types, examples (vs mitosis)

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Last Updated on May 23, 2020 by Sagar Aryal Binary fission is a type of asexual reproduction where a single living cell or an organelle grows twice its size and then splits into two identical daughter cells, where each of these daughter cells has the potential to grow into the size of the original cell or organelle.

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Mitosis is the phase of the cell cycle where chromosomes in the nucleus are evenly divided between two cells. When the cell division process is complete, two daughter cells with identical genetic material are produced.

Interphase

Before a dividing cell enters mitosis, it undergoes a period of growth called interphase. About 90 percent of a cell's time in the normal cell cycle may be spent in interphase.

G1 phase: The period prior to the synthesis of DNA. In this phase, the cell increases in mass in preparation for cell division. The G1 phase is the first gap phase.

S phase: The period during which DNA is synthesized. In most cells, there is a narrow window of time during which DNA is synthesized. The S stands for synthesis.

G2 phase: The period after DNA synthesis has occurred but prior to the start of prophase. The cell synthesizes proteins and continues to increase in size. The G2 phase is the second gap phase.

In the latter part of interphase, the cell still has nucleoli present.

The nucleus is bounded by a nuclear envelope and the cell's chromosomes have duplicated but are in the form of chromatin.

In prophase, the chromatin condenses into discrete chromosomes. The nuclear envelope breaks down and spindles form at opposite poles of the cell. Prophase (versus interphase) is the first true step of the mitotic process. During prophase, a number of important changes occur:

Chromatin fibers become coiled into chromosomes, with each chromosome having two chromatids joined at a centromere.

The mitotic spindle, composed of microtubules and proteins, forms in the cytoplasm.

The two pairs of centrioles (formed from the replication of one pair in Interphase) move away from one another toward opposite ends of the cell due to the lengthening of the ​microtubules that form between them.

Polar fibers, which are microtubules that make up the spindle fibers, reach from each cell pole to the cell's equator.

Kinetochores, which are specialized regions in the centromeres of chromosomes, attach to a type of microtubule called kinetochore fibers.

The kinetochore fibers "interact" with the spindle polar fibers connecting the kinetochores to the polar fibers.

The chromosomes begin to migrate toward the cell center.

In metaphase, the spindle reaches maturity and the chromosomes align at the metaphase plate (a plane that is equally distant from the two spindle poles). During this phase, a number of changes occur:

The nuclear membrane disappears completely.

Polar fibers (microtubules that make up the spindle fibers) continue to extend from the poles to the center of the cell.

Chromosomes move randomly until they attach (at their kinetochores) to polar fibers from both sides of their centromeres.

Chromosomes align at the metaphase plate at right angles to the spindle poles.

Chromosomes are held at the metaphase plate by the equal forces of the polar fibers pushing on the centromeres of the chromosomes.

In anaphase, the paired chromosomes ( sister chromatids) separate and begin moving to opposite ends (poles) of the cell. Spindle fibers not connected to chromatids lengthen and elongate the cell. At the end of anaphase, each pole contains a complete compilation of chromosomes. During anaphase, the following key changes occur:

The paired centromeres in each distinct chromosome begin to move apart.​

Once the paired sister chromatids separate from one another, each is considered a "full" chromosome. They are referred to as daughter chromosomes.​

Through the spindle apparatus, the daughter chromosomes move to the poles at opposite ends of the cell.​

The daughter chromosomes migrate centromere first and the kinetochore fibers become shorter as the chromosomes near a pole.​

In preparation for telophase, the two cell poles also move further apart during the course of anaphase. At the end of anaphase, each pole contains a complete compilation of chromosomes.

In telophase, the chromosomes are cordoned off into distinct new nuclei in the emerging daughter cells. The following changes occur:

The polar fibers continue to lengthen.

Nuclei begin to form at opposite poles.

The nuclear envelopes of these nuclei form from remnant pieces of the parent cell's nuclear envelope and from pieces of the endomembrane system.

Nucleoli also reappear.

Chromatin fibers of chromosomes uncoil.

After these changes, telophase/mitosis is largely complete. The genetic contents of one cell have been divided equally into two.

Cytokinesis

Cytokinesis is the division of the cell's cytoplasm. It begins prior to the end of mitosis in anaphase and completes shortly after telophase/mitosis. At the end of cytokinesis, two genetically identical daughter cells are produced. These are diploid cells, with each cell containing a full complement of chromosomes.

Cells produced through mitosis are different from those produced through meiosis. In meiosis, four daughter cells are produced. These cells are haploid cells, containing one-half the number of chromosomes as the original cell. Sex cells undergo meiosis. When sex cells unite during fertilization, these haploid cells become a diploid cell.​

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During mitosis, chromosomes are duplicated and divided evenly between two cells. The process begins with interphase and ends with cytokinesis.

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Mitosis is a method of cell division in which a cell divides and produces identical copies of itself.

Credit: Giovanni Cancemi | Shutterstock

The primary mechanism by which organisms generate new cells is through cell division. During this process, a single "parent" cell will divide and produce identical "daughter" cells. In this way, the parent cell passes on its genetic material to each of its daughter cells. First, however, the cells must duplicate their DNA. Mitosis is the process by which a cell segregates its duplicated DNA, ultimately dividing its nucleus into two.

Cell division is a universal process among living organisms. In 1855, Rudolf Virchow, a German researcher, made a fundamental observation about all living creatures: every cell originates from another cell, or " omnis cellula e cellula," in the original Latin, as author Myron Shultz recounts in a 2008 article in the journal Emerging Infectious Diseases.

The mechanisms of cell division vary between prokaryotes and eukaryotes. Prokaryotes are single-celled organisms, such as bacteria and archaea. They have a simple internal structure with free-floating DNA. They use cell division as a method of asexual reproduction, in which the genetic makeup of the parent and resulting offspring are the same. One common mechanism of asexual reproduction in prokaryotes is binary fission. During this process, the parent cell duplicates its DNA and increases the volume of its cell contents. Eventually, a fissure emerges in the center of the cell, leading to the formation of two identical daughter cells.

The cells of eukaryotes, on the other hand, have an organized central compartment, called the nucleus, and other structures, such as mitochondria and chloroplasts. Most eukaryotic cells divide and produce identical copies of themselves by increasing their cell volume and duplicating their DNA through a series of defined phases known as the cell cycle. Since their DNA is contained within the nucleus, they undergo nuclear division as well. "Mitosis is defined as the division of a eukaryotic nucleus," said M. Andrew Hoyt, a professor of biology at Johns Hopkins University, "[though] many people use it to reflect the whole cell cycle that is used for cell duplication."

Like prokaryotes, single-celled eukaryotes, such as amoeba and yeast, also use cell division as a method of asexual reproduction. For complex multicellular eukaryotes like plants and animals, cell division is necessary for growth and the repair of damaged tissues. Eukaryotic cells can also undergo a specialized form of cell division called meiosis, which is necessary to produce reproductive cells like sperm cells, egg cells and spores.

The eukaryotic cell cycle is a series of well-defined and carefully timed events that allow a cell to grow and divide. According to Geoffery Cooper, author of " The Cell: A Molecular Approach, 2nd Ed." (Sinauer Associates, 2000) most eukaryotic cell cycles have four phases:

G1 phase (first gap phase): During this phase cells that are intended for mitosis, grow and carry out various metabolic activities.

S phase (synthesis phase): During this phase, the cell duplicates its DNA. Eukaryotic DNA is coiled around spherical histone proteins to create a rod-shaped structure called the chromosome. During the S phase, each chromosome generates its copy, or sister chromatid. The two sister chromatids fuse together at a point called the centromere, and the complex resembles the shape of the letter "X."

G2 phase (second gap phase): During this phase the cell continues to grow and generate proteins necessary for mitosis.

(G1, S and G2 phases are collectively referred to as "interphase.")

M phase (mitosis): Mitosis involves the segregation of the sister chromatids. A structure of protein filaments called the mitotic spindle hooks on to the centromere and begins to contract. This pulls the sister chromatids apart, slowly moving them to opposite poles of the cell. By the end of mitosis each pole of the cell has a complete set of chromosomes. The nuclear membrane reforms, and the cell divides in half, creating two identical daughter cells.

Chromosomes, become highly compacted during mitosis, and can be clearly seen as dense structures under the microscope.

The resulting daughter cells can re-enter G1 phase only if they are destined to divide. Not all cells need to divide continuously. For example, human nerve cells stop dividing in adults. The cells of internal organs like the liver and kidney divide only when needed: to replace dead or injured cells. Such types of cells enter the G0 phase (quiescent phase). They remain metabolically active and only move into the G1 phase of the cell cycle when they receive the necessary molecular signals, according to Cooper.

Mitosis is divided into four stages, according to course materials from the University of Illinois at Chicago. The characteristic stages are also seen in the second half of meiosis.

Prophase: The duplicated chromosomes are compacted and can be easily visualized as sister chromatids. The mitotic spindle, a network of protein filaments, emerges from structures called centrioles, positioned at either end of the cell. The mitotic spindle is flexible and is made of microtubules, which are in turn made of the protein subunit, tubulin.

Metaphase: The nuclear membrane dissolves and the mitotic spindle latches on to the sister chromatids at the centromere. The mitotic spindle can now move the chromosomes around in the cell. "You can make an analogy to a girder that's holding up a skyscraper," said Hoyt. "Except the girder can assemble and disassemble very rapidly. They are structural elements that are extremely dynamic." By the end of metaphase, all the chromosomes are aligned in the middle of the cell.

Anaphase: The mitotic spindle contracts and pulls the sister chromatids apart. They begin to move to opposite ends of the cell.

Telophase: The chromosomes reach either end of the cell. The nuclear membrane forms again and the cell body splits into two (cytokinesis).

At the end of mitosis, one cell produces two genetically identical daughter cells.

A powerful light microscope captures this scene from the process of mitosis.

Credit: Jane Stout, research associate in the laboratory of Claire Walczak, Indiana University.

The various events of the cell cycle are tightly regulated. If errors occur at any one stage, the cell can stop cell division from progressing. Such regulatory mechanisms are known as cell cycle checkpoints, according to Cooper. There are three checkpoints within the G1, G2 and M phases. Damaged DNA stops cell cycle progression in the G1 phase, ensuring that an aberrant cell will not be replicated. The G2 checkpoint responds to incorrectly duplicated, or damaged DNA. It prevents cells from moving into the M phase until the DNA is replicated correctly, or until the damage is repaired. The M phase checkpoint can halt the cell cycle in metaphase. It ensures that all the sister chromatids are properly hooked up to the mitotic spindle and that sister chromatids move towards opposite ends of the cell.

"If things go wrong and are not corrected, you end up with some cells that get extra chromosomes and some that are deficient," Hoyt said. "Often those cells have a genotype[DNA sequence] that won't support the life of the cell, and the will cell die. That's usually a good thing."

Sometimes, abnormal cells manage not only to survive, but also to proliferate. Most often, these cells are implicated in cancer. "It [the cell] may have an extra copy of a chromosome that has an oncogene on it. And that's going to start pushing the cell cycle forward when it shouldn't be going forward," Hoyt said. "That's a first step toward cancer progression." Cancerous cells are known to go through rampant and unregulated cell divisions.

The relationship between the cell cycle and cancer has led to the development of a class of cancer drugs that specifically target cancer cells during mitosis. According to anarticle published in 2012 in the journal Cell Death & Disease, "this strategy encompasses a prolonged arrest of cells in mitosis, culminating in mitotic cell death."

For example, microtubule poisons stop mitosis by targeting microtubules, the main component of the mitotic spindle. Damaging these thin, hollow, microscopic protein filaments ultimately prevents sister chromatids from being pulled apart. Examples of microtubule poisons are the medications paclitaxel (Taxol) and vinca alkaloids, which are used to treat a range of cancers, including certain ovarian and breast cancers.

However, microtubule poisons are not without their limitations. According to a 2018 review article published in the journal EMBO Reports, these drugs can sometimes be toxic to brain cells, or cancer cells can become drug-resistant and avoid being killed. In an effort to find alternate solutions, researchers are looking to develop drugs that target other aspects of mitosis. In 2016, the Food and Drug Administration (FDA) approved the use of the new drug Palbociclib in combination with existing anti-cancer drugs to treat certain breast cancers. Palbociclib works by keeping cancer cells frozen in the G1 phase, according to a 2017 review article published in the journal Nature Reviews Cancer.

The compounds tested in clinical trials so far have had some success but have not been as effective as microtubule poisons, according to EMBO Reports. Nevertheless, targeting mitosis in the treatment of cancer remains an active area of research.

Additional resources

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The primary mechanism by which organisms generate new cells is through cell division. During this process, a single "parent" cell will divide and produce identical "daughter" cells. In this way, the parent cell passes on its genetic material to each of its daughter cells. First, however, the cells must duplicate their DNA.

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- When cells must move materials in an opposite direction - against a concentration gradient.
- Active transport requires Energy.
- Proteins or Pumps are found in the cell membrane transport molecules across the membrane.

Molecular Transport - Proteins are used to move small molecules such as calcium, potassium, and sodium ions across the membrane

Endocytosis

- cell takes in large particles by engulfing them

Phagocytosis - "cell eating" - extensions off cytoplasm surround a particle and package it within a food vacuole and then the cell engulfs it. Ex. Amoebas use this process.

Pinocytosis - the process of taking up liquid from the surrounding environment. Tiny pockets form along the membrane, fill with liquid, and pinch off.

Exocytosis

- cell gets rid of particles, opposite of endocytosis
- remember the vesicles created by the Golgi Body? These are removed from the cell by exocytosis

Sodium - Potassium Pump

The cell removes 3 sodium ions for every 2 potassium ions that enter the cell. This mechanism requires energy.

Think about it.....why does the cell NOT want sodium to build up within its cytoplasm?

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When cells must move materials in an opposite direction - against a concentration gradient. - Active transport requires Energy. - Proteins or Pumps are found in the cell membrane transport molecules across the membrane.

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Diffusion

-the process by which molecules spread from areas of high concentration, to areas of low concentration. When the molecules are even throughout a space - it is called EQUILIBRIUM

Concentration gradient - a difference between concentrations in a space.

Molecules will always move down the concentration gradient, toward areas of lesser concentration. Think of food coloring that spreads out in a glass of water, or air freshener sprayed in a room.

Selectively Permeable - membranes that allow some things through, the cell membrane is selectively permeable, water and oxygen move freely across the cell's membrane, by diffusion
Words You Should Know:
Diffusion

Osmosis

Gradient

Equilibrium

Selectively Permeable

Passive Transport

Active Transport

Isotonic

Hypertonic

Hypotonic

Contractile Vacuole

Carrier Protein

Facilitated Diffusion

Osmosis - the diffusion of water (across a membrane)

Water will move in the direction where there is a high concentration of solute (and hence a lower concentration of water.

A simple rule to remember is:

Salt is a solute, when it is concentrated inside or outside the cell, it will draw the water in its direction. This is also why you get thirsty after eating something salty.

Type of Solutions

Isotonic Solutions

If the concentration of solute (salt) is equal on both sides, the water will move back in forth but it won't have any result on the overall amount of water on either side.

" ISO" means the same

Hypotonic Solutions

The word " HYPO" means less, in this case there are less solute (salt) molecules outside the cell, since salt sucks, water will move into the cell.

The cell will gain water and grow larger. In plant cells, the central vacuoles will fill and the plant becomes stiff and rigid, the cell wall keeps the plant from bursting

In animal cells, the cell may be in danger of bursting, organelles called CONTRACTILE VACUOLES will pump water out of the cell to prevent this.

Hypertonic Solutions

The word " HYPER" means more, in this case there are more solute (salt) molecules outside the cell, which causes the water to be sucked in that direction.

In plant cells, the central vacuole loses water and the cells shrink, causing wilting.

In animal cells, the cells also shrink.

In both cases, the cell may die.

This is why it is dangerous to drink sea water - its a myth that drinking sea water will cause you to go insane, but people marooned at sea will speed up dehydration (and death) by drinking sea water.

This is also why "salting fields" was a common tactic during war, it would kill the crops in the field, thus causing food shortages.

Diffusion and Osmosis are both types of PASSIVE TRANSPORT - that is, no energy is required for the molecules to move into or out of the cell.

Sometimes, large molecules cannot cross the plasma membrane, and are "helped" across by carrier proteins - this process is called facilitated diffusion.

Go to notes on ACTIVE TRANSPORT

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the process by which molecules spread from areas of high concentration, to areas of low concentration. When the molecules are even throughout a space - it is called EQUILIBRIUM Concentration gradient - a difference between concentrations in a space. Molecules will always move down the concentration gradient, toward areas of lesser concentration.

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As can be seen, anatomy can be studies in multiple ways, and at various levels. Understanding the hierarchy of these levels, provides context to the complexity of the human organism. The simplest level of organization (although first year chemistry students would disagree) is the chemical level of organization. At this level, simple atoms combine to form relatively simple molecules. For example, carbon dioxide (CO ₂) is made up of one carbon atom, and two oxygen atoms, and water (H ₂O) is made up of two hydrogen atoms and one oxygen atom. Macromolecules ( macro: big) are larger and more complex, and include four key types in the human body; carbohydrates (sugars), lipids (fats), proteins and nucleic acids (DNA). These four macromolecules form the building blocks of the next level of organization: the cellular level. Cells are the smallest units of life and are responsible for regulating their own environment. The four macromolecules, interact to complete complex tasks for the cell, like generating energy (ATP) or producing muscle contractions (through the interactions of two protein complexes: actin and myosin).

The tissue level of organization consists of a group of cells that work together to accomplish one or more specific functions. There are only four distinct types of tissue in an adult human. Muscle tissue is specialized for contraction to generate movement; neural tissue is specialized for generating action potentials for rapid communication within the body; epithelial tissue provides a physical barrier for entry into the body and produces specialized secretions via glands; and connective tissue shows the greatest variability of all of the tissues, and forms much of the structure of the body (among many other things).

The organ level of organization is when two or more tissues work together for a specific function. For example, the bladder consists of an inner lining of epithelial tissue, bound by various connective tissues to (smooth) muscle. Throughout the bladder, there are also neurons that control the muscle tissue directing it to contract or relax during the urination reflex.

The organ system level of organization is when two or more organs work together for a specific function. The bladder mentioned, when combined with the kidneys (another organ), and the ureters ("tubes" connecting the kidneys to the bladder, form the urinary system (or urinary tract). The kidneys filter the blood, and the waist products drain through the ureters to be stored in the bladder. The waist is eliminated from the body when we urinate.The urinary system is one of the eleven body systems that can be examined using systemic anatomy.

The most complex level of organization is the organismal level, where all eleven organ systems function in the human organism, the whole living person.

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As can be seen, anatomy can be studies in multiple ways, and at various levels. Understanding the hierarchy of these levels, provides context to the complexity of the human organism. The simplest level of organization (although first year chemistry students would disagree) is the chemical level of organization.

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Overview of animal and plant cells | Biology | Khan Academy

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Characteristic of LIfe (Cambell & Reece)

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A hypothesis is a prediction of the outcome of a test. It forms the basis for designing an experiment in the scientific method. A good hypothesis is testable, meaning it makes a prediction you can check with observation or testing. Here are different hypothesis examples.
Null Hypothesis Examples
The null hypothesis (H ₀) is also known as the zero-difference or no-difference hypothesis. It predicts that changing one variable (independent variable) will have no effect on the variable being measured (dependent variable).

Plant growth is unaffected by temperature.

If you increase temperature, then solubility of salt will increase.

Incidence of skin cancer is unrelated to ultraviolet light exposure.

All brands of light bulb last equally long.

Cats have no preference for the color of cat food.

All daisies have the same number of petals.

Sometimes the null hypothesis is used to show there is a correlation between two variables. For example, if you suspect plant growth is affected by temperature, you could state the null hypothesis. Why would you do this, rather than say "If you change temperature, plant growth will be affected"? The answer is because it's easier to apply a statistical test to show, with a high level of confidence, a null hypothesis is correct or incorrect.
Research Hypothesis Examples
A research hypothesis (H ₁) is a type of hypothesis used to design an experiment. This type of hypothesis is often written as an if-then statement because it's easy to identify the independent and dependent variables and see how one affects the other. If-then statements are used to explore cause and effect. In other cases, the hypothesis is stated to show a correlation between two variables. Here are some research hypothesis examples:

If you leave the lights on, then it will take longer for people to fall asleep.

If you refrigerate apples, they will last longer before going bad.

If you keep the curtains closed, then less electricity will be used to heat or cool the house (electric bill will be lower).

If you leave a bucket of water uncovered, then it will evaporate more quickly.

Goldfish lose their color if they are not exposed to light.

Workers who take vacations are more productive than those who never take time off.

Is It Okay To Disprove a Hypothesis?
Yes! You may even choose to write your hypothesis in such a way that it can be disproved because it's easier to prove a statement is wrong than to prove it is right. In other cases, if your prediction is incorrect, that doesn't mean the science is bad. Revising a hypothesis is common. It demonstrates you learned something you did not know before you conducted the experiment.

Test Yourself with a Scientific Method Quiz

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A hypothesis is a prediction of the outcome of a test. It forms the basis for designing an experiment in the scientific method. A good hypothesis is testable, meaning it makes a prediction you can check with observation or testing. Here are different hypothesis examples.

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The terms hypothesis and prediction are sometimes used interchangeably, but it's important to understand the difference and include them as distinct statements in the lab report.

Before we get to the hypothesis, we must start at the beginning of the research process, known as the scientific method, with a research question. Research questions often stem from observations - these observations can be made in passing, or they might come as a result of previous research. For example, while out bird watching, you notice that a certain species of sparrow made all of its nests with the same material: grasses. From that observation, you might wonder, "Why are the nests of sparrows made with grasses rather than twigs?" This is your research question.

A hypothesis is, in simple terms, the answer to your research question. From your question about sparrow nests, you would derive a hypothesis based on your background research. You might hypothesize, "Sparrows use grasses in their nests rather than twigs because grasses are the more abundant material in their habitat."

A prediction, on the other hand, is specific to the study and experiment that you design to test your hypothesis. It's the outcome you would observe if your hypothesis were supported. Predictions are often written in the form of "if, then" statements, as in, "if my hypothesis is true, then this is what I will observe." Following our example, you could design an experiment wherein birds are provided with differing quantities of the two nest materials, and you could predict that, "If sparrows use grasses in their nests rather than twigs because grasses are the more abundant material in their habitat, then when twigs are more abundant, sparrows will use those in their nests."

A more refined prediction might alter the wording so as not to repeat the hypothesis verbatim: "If sparrows choose nesting materials based on their abundances, then when twigs are more abundant, sparrows will use those in their nests."

Let's take a look at another example:

Hypothesis: When planted alongside asparagus, marigolds will deter asparagus beetles.

Prediction: If marigolds deter asparagus beetles, then asparagus plants planted alongside marigolds will host fewer asparagus beetles than asparagus plants planted on their own.

Resist the urge to change your hypotheses and predictions based on the outcome of your study or experiment. Your work will not be negated (or marked down) because you didn't find what you had expected. To the contrary, an unexpected result often provides more area for discussion - consider what about your background research led you to your hypotheses and predictions and discuss why your research had an unpredicted outcome.

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Research Question Hypothesis Prediction Example Final Note The terms hypothesis and prediction are sometimes used interchangeably, but it's important to understand the difference and include them as distinct statements in the lab report.