Edexcel A2 Biology 1

Welcome to your Edexcel A2 Biology 1

1. The statement which proves the common ancestry between different species.
2. Choose the correct order of formation.
3. Which is not an evidence to indicate the common ancestry shared between different species?
4. What is homozygous genotype?
5. What is a genetic drift?
6. The presence of 2 genes on the same chromosome so that they tend to be inherited together and do not assort independently.
7. How many pairs of autosomes are present in a human being?
8. An example of a sex linked disorder.
9. Which does not describe the niche of an organism in an ecosystem?
10. Which mechanism(s) allow changes to the pool of genes?

a) Natural selection
b) Genetic drift
c) Speciation
d) Gene flow
11. Choose the word which is not very closely related to an allele.
12. Select the incorrect statement out of the following.
13. Which is not a factor affecting the carrying capacity of an ecosystem?
14. What is heterozygous genotype?
15. Which of the following is not an evidence for evolution?
16. Select the incorrect pair out of the following.
17. Which of the following does not occur if a population becomes isolated from other populations of the same species?
18. Select the incorrect statement regarding ecosystems.
19. A change in the allele frequency of a population is ___________.
20. Reasons for variation in the phenotypes of organisms in a population.

a) Environmental factors
b) Genetic factors
c) Unwillingness to change
d) Variations in the genotypes
21. Select the incorrect statement out of the following.
22. Select the incorrect statement regarding sex chromosomes.
23. Select the incorrect statement regarding alleles.
24. Which is not a condition for Hardy-Weinburg equilibrium?
25. Which of the following is an example for human blood groups?