- In I/GCSE Biology, differences in characteristics are called variation. There is variation within a species but much more variation between different species. The variation within a species can make classification difficult.
- Scientists have to make sure any ‘new’ organism is not just a hybrid or due to variation in a known species. This is done by finding more than one of the organisms.
- These differences in variation within a species can be caused by genes or the environment.
Genetic variation 🧬🧬
- All plants and animals have characteristics that are in some ways similar to their parents’. This is because an organism’s characteristics are determined by the genes inherited from their parents.
- Most animals, and significant numbers of plants, get some genes from the mother and some from the father.
- The combining of these genes from the two parents causes genetic variation. No two of the species are genetically identical.
- Genetic variation also occurs due to mutations – changes in an organism’s genes. These changes can cause differences in an organism’s characteristics.
- Some characteristics are determined only by genes.
Diagram: The details of gene mutation
Environmentally influenced variation
- The environment that organisms live and grow in also causes differences between members of the same species – this is called environmental variation.
- Environmental variation covers a wider range of differences, such as losing a limb or dying your hair.
- Environmental factors that can cause variation include diet, exercise, temperature, light level, amount of water etc.
Both are influential !!! 😝😝😝
- In I/GCSE Biology, most characteristics that we have are determined by a mixture of genetic and environmental factors.
- For example, the maximum height that an animal or plant can grow to is determined by its genes. But whether it actually grows that tall depends on its environment.
That's the end of the topic!
Drafted by Joey (Biology)