https://padlet.com/davicente127/pgeom0n61ya3byco Hecho con una mente abierta en-us 2021-10-12 14:57:20 UTC 2021-10-29 18:37:52 UTC hello@padlet.com davicente127 https://padlet.com/davicente127/pgeom0n61ya3byco/wish/1819981831

It is the process of fertilization that gametes combine to make a cell with a diploid set of chromosomes.

Two parietal cells are required for off spring to form.

It is the driving force behind speciation that new species are formed from existing ones that make new changes in the population through sexual reproduction.

At fertilization, the male and female gametes fuse outside the body of the organism

having half the gametes of the chromosome number is an important aspect of sexual reproduction

Sexual reproduction is of two types of male and female gametes; allogamy and autogamy

Examples of sexual reproduction are seen in higher organisms such as humans and other mammals and plants 

The formation of gametes with half the number of chromosomes is an important aspect of sexual reproduction.

]]> 2021-10-15 16:06:51 UTC https://padlet.com/davicente127/pgeom0n61ya3byco/wish/1819981831 davicente127 https://padlet.com/davicente127/pgeom0n61ya3byco/wish/1819985757

• It is the absence of male and female gametes and the lack of change in the number of chromosomes in the offsprin
• No specific gametes are formed, somatic cells act like gametes 
• It is considered a more primitive mode of reproduction, since it occurs mainly in living beings such as bacteria and fungi.
• Mitosis occurs when the genetic material of the stem cell duplicates itself before dividing it into two equal halves.
• The lack of diversity makes individuals susceptible to similar environmental and physical conditions.
• It is fast, which is useful for organisms whose strategy to survive is to reproduce quickly.
• It is a uniparental process that can occur within a single organism and therefore no partners are required for the process.
• Vegetative propagation occurs in plants where new plants form from plant parts without the formation of seeds or spores.

]]> 2021-10-15 16:08:59 UTC https://padlet.com/davicente127/pgeom0n61ya3byco/wish/1819985757 davicente127 https://padlet.com/davicente127/pgeom0n61ya3byco/wish/1820012100

Reproducion is a biological process, of sexual and asexual type,which guarantees life succession

All living organism use cellular division as a reproductive and growth mechanism of individual

Unicellular beings use it for reproduction and the pepetuation of species

For multicellular organism it is cyclic process destined to cell reproduction

Cellular division is donde through the cellular cycle in which materials needed for a new cell are replicated

 At same time each cell can divide itself again which means that cellular division cycle 

in order for strucuture to divide itself in two identical ones it has to be duplicate

The cellular division goes throught three key moments

]]> 2021-10-15 16:22:35 UTC https://padlet.com/davicente127/pgeom0n61ya3byco/wish/1820012100 davicente127 https://padlet.com/davicente127/pgeom0n61ya3byco/wish/1842614488

Mitosis is performed by unicellular and multicellular eukaryotes.Bacteria have their own version of mitosis called “binary fission”

his is distinct from meiosis as bacteria typically have one circular chromosome,which is not contained within a nucleus, like eukaryotic chromosomes.

The process can take over 10 hours for mammalian cells in culture

Mitosis is the Greek word for thread, after the thread-like chromosomes that can be seen under the microscope in dye-stained cells during cell division.

Walther Flemming in his 1882 work “Cell substance, nucleus and cell division.

is is distinct from meiosis as bacteria typically have one circular chromosome,which is not contained within a nucleus, like eukaryotic chromosomes.

budding yeast can take ~80 minutes to complete a cell cycle, whilst bacteria can divide every 20 minutes.

which is not contained within a nucleus, like eukaryotic chromosomes.

]]> 2021-10-25 18:10:29 UTC https://padlet.com/davicente127/pgeom0n61ya3byco/wish/1842614488 davicente127 https://padlet.com/davicente127/pgeom0n61ya3byco/wish/1842631400

To create gametes with only one copy of the organism’s genetic information, in preparation for sexual reproduction.

Various steps in meiosis create opportunity for genetic diversity in the daughter cells. This is the raw substrate for evolution.

Four haploid cells with different genetic information.

Only organisms which perform sexual reproduction. Archaeaand bacteria do not do this, so it might be tempting to think that unicellularorganisms do not sexually reproduce.

However, there are exceptions; buddingyeast will form haploid spores under nutritional deprivation.     

Meiosis has various timescales in different organisms, which can be affected by several factors including temperature and environment of the organism, and the amount of nuclear DNA

The process lasts 6 hours in yeast but can last more than 40 years in human females, due to a developmental hold at prophase I, until ovulation. Other examples are 1-2 days in male fruit flies and ~ 24 days in human males.

Errors in meiosis can lead to the wrong number of chromosomes ending up in germ cells, this is called aneuploidy. This can trigger miscarriage, but is occasionally tolerated. One example is Down’s syndrome, caused by trisomy 21. Another example is Klinefelter syndrome, where XY males have an additional X chromosome.

]]> 2021-10-25 18:16:15 UTC https://padlet.com/davicente127/pgeom0n61ya3byco/wish/1842631400