1. Define the term "allele".
Answer
Different forms of the same gene.
2. Define genetic diversity.
Answer
Genetic diversity is the number of different alleles within a population.
3. Define the terms "species" and "population".
Answer
Species = organisms that are able to reproduce and produce fertile offspring.
Population = organisms from the same species that live in the same ecosystem or area.
4. Explain what the term "physiological adaptation" means.
Answer
Physiological adaptations are internal responses to external stimuli to help the organism survive.
5. The figure below shows the effect of natural selection on human birth weight. What type of selection is shown here ?
Answer
Stabilising because the mean is selected for and both extremes selected against.
6. Explain why the lack of genetic diversity in a population is a concern.
Answer
Having multiple alleles means that there is more variation within a population. If environmental conditions change, the species is more likely to have some individuals that are able to survive.
7. Explain how small isolated populations contribute to low genetic diversity.
Answer
Isolated populations breed only among themselves and do not interbreed with other groups. As a result, no new alleles are introduced into the population.
8. A group of scientists compared the genetic diversity of cheetahs with the genetic diversity of other big cats present in Africa. The figure below shows their findings. The numbers in brackets represent the number of gene loci investigated. Calculate the percentage of gene loci investigated that showed multiple alleles in the East African cheetah and the lion.
Answer
cheetah = 2/49 = 4%,
9. Use the figure above to explain which of the cats might be best adapted to environmental change.
Answer
Lions are among the most genetically diverse species. They are more likely to possess advantageous alleles, increasing the chances that some individuals can survive environmental changes.
10. Aye-ayes are primates that are dark brown/black and have a bushy tail that is larger than their body. They have big eyes that enable them to detect colour even when there is very little light, and large ears that are extremely sensitive. On each hand, they have long, thin fingers, with one especially long and mobile finger. They tap branches with their fingers to detect hollows in the branches where insect grubs might be found. They bite into the wood with their sharp teeth, and scoop out the grubs with their very long finger to eat them. Aye-ayes are nocturnal and spend their days sleeping in nests made within the tree branches. Identify the anatomical adaptations. For each one suggest how each adaptation helps aye-ayes to survive.
Answer
Nocturnal – helps them to remain out of sight of predators
Remain in trees − fewer predators in trees
Tap branches – helps with locating insects
11. Identify the behavioural adaptations of aye-ayes. For each one suggest how each adaptation helps them to survive.
Answer
Large ears – to hear potential predators
Good (colour) vision in dim light – helps to locate food sources
Long tail –for balance in trees
Sharp teeth – to chew wood
Specialised finger – to locate and eat insects
Dark colour – to camouflage in trees