# data[].attributes.body
A genome refers to the complete set of genetic material in an organism, including all of its DNA sequences. The size of a genome is typically measured in base pairs (bp) or more commonly in millions of base pairs (Mbp) or gigabases (Gb).

The human genome is approximately 3.2 billion base pairs (or 3,200 Mbp) in length.

Genome size can vary dramatically between species, from less than 1 Mbp in some bacteria to over 100,000 Mbp in certain plants.

# data[].attributes.body
Diploid cells (2n) have two complete sets of chromosomes; most adult body cells are diploid.

Haploid cells (n) have one set of chromosomes (half the number of diploid cells), usually are usually gametes (egg and sperm) used in sexual reproduction.

Some species have haploid cells in other parts of their life cycle.

Fertilisation fuses two haploid gametes → forms a diploid zygote.

Both gametes must have the same number of chromosomes for the zygote to be viable.

All body cells from the zygote carry the same chromosome number.

Exception: red blood cells lack a nucleus and contain no chromosomes.

# data[].attributes.body
Speciation is the evolutionary process by which a new species arises from an existing one, leading to distinct groups that can no longer interbreed to produce fertile offspring.

When a single population begins to split, the two groups may show some genetic and morphological differences, but they can still interbreed.

At this stage, it’s unclear whether they are just diverging populations or already separate species.

# data[].attributes.body
A species is a group of organisms that share similar traits, interbreed, and are reproductively isolated.

This definition focuses entirely on observable morphology (external appearance and internal structure).

# data[].attributes.body
The formal system by which all living species are classified

bi: two

nomial: name

nomenclature: naming system

-> Developed by Linnaeus in 1700s and is updated periodically at a series of international congresses.

-> it is the international standard used by scientists for naming species.

# data[].attributes.body
If you we look around us, there are no two living things that are totally identical, even if it is the same species. For example, us humans may differ from its eye color, body height, hair color, etc. Basically no organisms are totally the same.

# data[].attributes.body
Genome: all of the base sequences (genetic information) in an organism

Gene: a segment of DNA that codes for a particular protein

Unity → Species have the same genes in the same positions on their chromosomes

Diversity → The genes themselves can have different base sequences (alleles)

# data[].attributes.headline
Morphology Was Used Due to its Ease of Observation, Universality, and Comparative Simplicity

# data[].attributes.subject
Morphology Was Used Due to its Ease of Observation, Universality, and Comparative Simplicity

# data[].attributes.body
1. Ease of observation: Physical traits were visible and measurable, requiring no advanced tools.

2. Universality: All organisms exhibit morphological traits, enabling universal comparison.

3. Comparative simplicity: This allowed scientists to focus only on key traits, which allowed for systematic classification.

# data[].attributes.body
Karyotype: number and type of chromosome present in a cell or organism

Karyotyping: process of pairing & ordering the complete set of chromosomes within a cell, to provide a snapshot of an organism’s genetic profile. The chromosomes can then be photographed to generate a visual representation called a karyogram

Karyogram: photographs/diagrams in which the chromosomes of an organism are shown in in homologous pairs of decreasing length

to prepare:

Cells are cultured+allowed to divide

Chemicals used to arrest cells in metaphase (organized and condensed)

Stained

observed/photographed using a microscope

organized in decreasing size

# data[].attributes.body
This variation comes from two factors, which is genetic differences and environmental influences. Because of variation, some organisms are better suited for the environment, which is what drives the natural selection and evolution.

This means that variation is essential for the continuity of life in order to survive and change on earth, creating biodiversity.

# data[].attributes.body
According to the biological species concept, species is a group of organisms that can breed and produce fertile offspring.

Fertile: Able to conceive young/produce seed

# data[].attributes.body
1. Genus is written first and is Capitalized, followed by species in lower case

2. When typed it is written in italics

Ex: Homo sapiens

3. When handwritten it is underlined

4. If full name previously mentioned can be appreciated Ex: H. sapiens

5. Some species may occasionally have a sub-species designation.

Ex: Homo sapiens sapiens = modern humans.

# data[].attributes.body
When comparing genome sizes, it's important to understand the different units of measurement used:

Base pairs (bp): The smallest unit, representing a single pair of nucleotides.

Kilobases (kb): 1,000 base pairs.

Megabases (Mb or Mbp): 1,000,000 base pairs.

Gigabases (Gb): 1,000,000,000 base pairs.

# data[].attributes.headline
Advantegous of Binomial System for Naming Organism:

# data[].attributes.subject
Advantegous of Binomial System for Naming Organism:

# data[].attributes.body
✓Every organism has a unique name – no confusion/duplicates/ambiguity

✓Allows for the identification and comparison of organisms based on recognized characteristics

✓Allows all organisms to be named according to a globally recognized scheme à international collaboration/cooperation

✓Can show how closely related organisms are, allowing for the prediction of evolutionary links

✓Facilitates collection, sorting and grouping information about organisms

# data[].attributes.body
Whole genome sequencing (WGS) is currently used to analyze the entire DNA of an organism, which has revolutionized healthcare, research, and diagnostics. Its potential future applications continue to expand with technological advances. WGS helps identify rare genetic conditions, especially in children and newborns who present with unexplained symptoms.

# data[].attributes.body
Human to human, most of our DNA is the same (99.9%)

Single-nucleotide polymorphism

(SNP)

SNP: a position where there are differences in base sequences

Humans 5000 SNPs (out of 3 billion)

# data[].attributes.body
the use of this:

to identify chromosome abnormality

-> leading to abnormal conditions/syndromes

determining species types, because chromosome is a characteristic feature

determining the sex of the organism (XY or XX)

# data[].attributes.body
Asexual Reproduction: Organisms that reproduce asexually cannot be classified using this method

E.g. bacteria reproduce asexually, so the question of whether or not they can breed together is irrelevant

Fertile Hybrids: On rare occasions, animals of different species breed together and produce fertile offspring.

E.g. the so-called 'wholphin' is the fertile offspring from a cross between a melon-headed whale and a common bottlenose dolphin.

According to the biological species concept the wholphin would be a new species, but while scientists do believe that hybridisation can lead to new species, it needs to be a frequent event for this to occur, and wholphins are rare.

Note that the melon-headed whale is actually a species of dolphin, so the name 'wholphin' is a bit inaccurate.

Extinction: Some species are extinct, so it is not possible to breed them together with members of an existing species to determine the fertility of their offspring

E.g. the woolly mammoth is quite similar in morphology to modern elephants, though it is classified as a different species; there is no way of checking this classification using the biological species concept.

# data[].attributes.body
Personalized Medicine: The adoption of routine whole genome sequencing may not only inform therapeutic decision-making but also enable comprehensive preventive care and the construction of tailored health management strategies for individuals. This could extend to annual genomic evaluation as part of personalized healthcare maintenance

Neonatal Screening: The expansion of genome screening programs for neonates could facilitate the detection of genetic disorders, which supporting the early implementation of targeted interventions and significantly improving patient health.

Oncological Surveillance: Advancements in genomic monitoring, such as tumor, more sensitive and earlier detection of neoplastic disease (abnormal growth of cells --> tumour & cancer), informed monitoring of disease progression or recurrence, and personalization of cancer treatment.

Genome Editing and Therapeutics: Whole genome sequencing allows precise gene-editing initiatives (e.g., CRISPR technologies), enhancing the identification of optimal therapeutic targets and off-target effect mitigation in somatic and germline interventions

# data[].attributes.body
A characteristic feature that is able to deduce evolutionary relationships. Example, humans have 46 chromosomes, while chimpanzees have 48

It means that humans - chimps share a recent ancestor

it is hypothesized that chromosome 2 in humans arose from the fusion of chromosomes 12 and 13 in the primate ancestor

# data[].attributes.attachment_caption
Database contains DNA, mRNA, and Proteins for analysis of variation between genomes

# data[].attributes.headline
Eukaryotes can vary in size and base sequence, determined by the mass of DNA in the  nucleus

# data[].attributes.subject
Eukaryotes can vary in size and base sequence, determined by the mass of DNA in the  nucleus

# data[].attributes.body
- Variation in sizes means some species may have genes that don't belong to other species. For example, plants need chloroplast genes for photosynthesis, while humans don't need them.

- There is an online database containing information on DNA sequence

The function of the database:

Select a specific gene to compare

Select species to compare

Choose whether to compare amino acid sequences or DNA base sequences

- Comparison of eukaryotic species sequence data shows that the closely related organisms have more similar genes

# data[].attributes.body
Ethical issues in whole genome sequencing (WGS) include making sure people understand what they’re agreeing to because WGS can reveal a lot of unexpected genetic information. Protecting privacy is a big concern since genetic data is very personal and could be misused by employers or insurers. Even when data is anonymized, it’s sometimes possible to identify people. Another challenge is deciding whether to share unexpected findings that might affect a person or their family. Overall, clear rules and care are needed to balance the benefits of WGS with respecting people’s rights and privacy.

# data[].attributes.body
Provides a complete analysis of the entire genome, covering all genes and regions.

Detects a wide range of genetic variations, including small mutations, copy number changes, and larger structural variants.

Helps diagnose rare and complex diseases missed by other tests.

Enables personalized treatment plans, especially for cancer and pharmacogenomics.

Data can be reanalyzed in the future as new genetic knowledge emerges.

Useful for research to discover new disease genes and understand genetic mechanisms.

# data[].attributes.body
High cost compared to other genetic tests, though decreasing over time.

Generates massive amounts of data, requiring extensive analysis and storage resources.

Many genetic variants found have unknown significance, complicating interpretation.

Some genomic regions are difficult to sequence accurately with current methods.

May reveal incidental findings that cause anxiety or ethical challenges.

Takes longer to return results than some targeted tests.

# data[].attributes.headline
chromosome number and species differences

# data[].attributes.subject
chromosome number and species differences

# data[].attributes.body
Members of the same species have the same chromosome number (mutations are rare).

Species with different chromosome numbers usually cannot interbreed

. Chromosome number does not indicate how “advanced” a species is.

# data[].attributes.body
Several online databases provide genome size information for thousands of species:

Animal Genome Size Database: A comprehensive resource for animal genome sizes.

Plant DNA C-values Database: Contains genome size data for over 10,000 plant species.

NCBI Genome Database: Provides genome size information alongside other genomic data.

In genetics, the C-value is the amount of DNA in the haploid genome of an organism. It represents the amount of DNA contained within a single set of chromosomes or a single gamete.

The C-value Paradox

The C-value paradox highlights the discrepancy between the amount of DNA (C-value) and the complexity of the organism.

The paradox emphasizes that functional genes and their regulation, not total genome size, determine organism complexity

# data[].attributes.body
Several factors contribute to the variation in genome sizes across organisms:

1. Non-coding DNA: Many genomes contain large amounts of non-coding DNA, which does not directly code for proteins.

Repetitive sequences, transposons, and introns all contribute to genome size.

2. Polyploidy: The presence of multiple sets of chromosomes, common in plants, increases genome size.

3. Gene duplication: The duplication of genes or entire genomic regions can lead to larger genomes.

# data[].attributes.headline
Difficulties distinguishing between populations and species due to divergence of non-interbreeding populations during speciation

# data[].attributes.subject
Difficulties distinguishing between populations and species due to divergence of non-interbreeding populations during speciation

# data[].attributes.body
What is Non-Interbreeding Population?

A group of organisms that are reproductively isolated from each other, they cannot interbreed and produce fertile offspring.

There are some difficulties in defining the species concept, such as:

1. Asexual reproduction

The Biological Species Concept (based on interbreeding and producing fertile offspring) doesn’t work for organisms that reproduce asexually, like bacteria.

2. Fossil species

We can’t test whether extinct organisms interbred, so we rely only on morphology, which can be misleading.

3. Ring species

In some cases, populations of the same species are distributed in a ring shape around a geographic barrier. Neighboring populations can interbreed, but populations at the ends of the ring cannot, making it hard to draw a clear species boundary.

4. Hybridization

Different species sometimes interbreed (e.g., lions × tigers, or plants like wheat species), producing hybrids. This blurs the boundaries between species.

5. Cryptic species

Some species look almost identical morphologically but are genetically distinct and do not interbreed. Relying on appearance alone can fail here.

6. Variation within a species

Members of the same species can look very different (due to age, sex, environment, or genetic diversity), making classification difficult.

7. Different definitions

There are multiple competing species concepts (Biological, Morphological, Phylogenetic, Ecological, etc.), and each works better in some cases than others.

# data[].attributes.headline
Strenghts and Limitation of  Morphological Species Concept

# data[].attributes.subject
Strenghts and Limitation of  Morphological Species Concept

# data[].attributes.body
Strenghts

Provides a straightforward, visual method of classification without requiring complex tools.

Useful when only fossils or external features are available.

Enables field-based identification of organisms, which remains valuable in ecology and biodiversity studies.

Limitations

Morphologically similar organisms may not be closely related.

Morphologically different individuals may still belong to the same species.

Fails to account for cryptic species, which are genetically distinct but appear similar.