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In this topic of IBDP Biology, we will learn about classification.
Why is classification important?
- Vast diversity of living organisms – up to 100 million species.
- Allows us to identify the similarities and differences between organisms.
- Allows us to identify the evolutionary history of an organism.
- When it comes to IBDP Biology, it gives every organism a universal name, makes studying easier.
- Devised solely for human convenience – organisms actually form a continuum.
Concept of a species
- A group of organisms belong to a species if:
- They can reproduce together to produce fertile offspring.
- Closely related species may be able to reproduce to create offspring.
- These offspring are often infertile, eg mules from horses and donkeys.
- They cannot produce fertile gametes.
- Closely related species may be able to reproduce to create offspring.
- When it comes to IBDP Biology, they share observable similarities that members of other species do not possess.
- Biochemistry
- DNA
- Physical similarities
- Patterns of development - embryology
- Behavioural
- Same ecological niche
- They can reproduce together to produce fertile offspring.
- Closely related species may be behaviourally incompatible, so they cannot reproduce.
- However, this is difficult to define.
- Eg grizzly and polar bears can reproduce.
- They have different:
- Niche – different territories
- Behaviour – grizzly bears are more aggressive
- It is not known whether their offspring are fertile.
- Even if they are, they would still be defied as separate species, unless their hybrids were found to be freely reproducing.
Binomial system
- Each species is given a unique name
- When it comes to IBDP Biology, It involves the binomial system.
- Consists of genus and species in Latin:
- Eg Homo sapiens
You get it now. Now you can proceed to Part 2.
