Variation Flashcards
What is variation?
It’s the differences within a species, E.g. in a room full of people you see different colour hair, individually shape noses ,a variety of heights etc.
True or false- organisms of the same species have differences?
True. Different species look different, a dog definitely doesn’t look like a daisy. Even organisms of the same species will usually look at least slightly different, this is due to variation.
What are the two types of variation?
Genetic variation and environmental variation.
What can cause genetic variation?
Different genes
Explanation of the occurrence of genetic variation
All plants and animals have characteristics about someways similar to their parents. This is because an organisms characteristics are determined by the genes inherited from their parents. These genes are passed in sex cells (gametes) which the offspring develop from. Most animals and quite a lot of plants get some genes from the mother and some from the Father. This combination of genes from two-parents causes genetic variation- no two of the species are genetically identical other than identical twins. Some characteristics determined only by genes (e.g. violet flower colour.) In animals these include: eyecolour, blood-group and inherited disorders e.g. Haemophilia or cystic fibrosis.
Can characteristics be influenced by the environment?
Yes
What is environmental variation?
The environment organisms live and grow in also causes differences between members .
What does environmental variation cover?
A wide range of differences from losing your toes in a piranha attack, to getting a suntan, to having yellow leaves,and so on. Basically, any difference that has been caused by the conditions something lives in, is an environmental variation.
Are characteristics due to genes and environment?
Yes,most characteristics (e.g. bodyweight,height, skin colour ,condition of teeth ,academical ,athletic prowess,etc) are determined by a mixture of genetic and environmental factors. For example, the maximum height an animal or planet could grow to is determined by genes. But whether it actually grows that all depends on its environment ( e.g. how much food it gets )
