Edexcel A2 Biology 2

Welcome to your Edexcel A2 Biology 2

1. Unique species of plants and animals in the Hawaiian and Galapagos islands is an example of ____________.
2. A situation where Hardy-Weinburg calculations does not apply.
3. Which selection favours both extremes of continuous variation?
4. Answer the following 4 questions by reading the given description. In an eggplant that has one allele for brown stems and one allele for green stems, the stems are exactly the same shade of brown as in a plant that has two alleles for brown stems. The allele for brown stems is dominant, and the allele for green stems is recessive. What is the genotype of eggplants with green stems?
5. The above cross is an example of a _________.
6. Select the correct statement about sympatric speciation.
7. Select the incorrect sentence out of the following.
8. Select the incorrect statement regarding allopatric speciation.
9. Select the mechanisms which contribute towards changing the pool of genes.

a) Natural selection
b) Gene transfer
c) Genetic drift
d) Speciation
10. Change in allele frequencies due to a new environmental factor or a new allele.
11. A brown stemmed eggplant has 2 genotypes. In order to determine its exact genotype, it could be crossed with a ___________.
12. What is the possible genotype of an eggplant with brown stems?
13. What does q2 represent in the Hardy-Weinburg equation p2+2pq+q2=1?
14. A behavioural barrier which could cause sympatric speciation.
15. An ecological barrier which could cause sympatric speciation.
16. Which of the following geographical barriers can lead towards allopatric speciation?

a) Rivers
b) Mountain ranges
c) Continental drift
d) Small pond
17. Clutch size in birds is an example of ___________.
18. The mark-release-recapture method of sampling is used among __________.
19. A process which does not facilitate natural selection.
20. Select the incorrect statement regarding mutations.
21. Industrial melanism is an example of ___________.
22. The primary source of genetic variation within a population of a species.
23. Within a population of rabbits, the colour black (B) is dominant over the colour white (b). And, 30% of all rabbits are white. What is the percentage of heterozygous rabbits in the population?
24. What is the meaning of 'Allopatric'?