The diagram shows two varieties of moths in England.

a. Which variety was more common when there was more air pollution? Give a reason as well.

Dark-colored moths were more common due to industrial melanism, as they blended better with polluted, dark tree bark, avoiding predation.

b. Which variety is more common in England nowadays? Give a reason as well.

Light-colored moths are now more common because environmental pollution has decreased, making lighter moths better camouflaged.

Related Questions:

  1. Write the differences between:
  2. Name sources of variation.
  3. Give examples of artificial selection.
  4. What kind of gametes would be produced by organisms having the following genotypes?
  5. Two white sheep produce a black offspring. What must the parents’ genotype for colour be? What is the probability that the next offspring will be black?
  6. Among the following genotypes, which ones are heterozygous and which are homozygous? Which of the genotypes have the same phenotype?
  7. Differentiate between genotype and phenotype.
  8. What is meant by polygenic inheritance? Give an example.
  9. How do genes control inheritance of characters?
  10. Explain the composition of chromatin material.
  11. Give an account of genes and alleles.
  12. Describe the role of genes in protein synthesis.
  13. State and explain Mendel’s law of segregation.
  14. State and explain Mendel’s law of independent assortment.
  15. What is co-dominance? Explain with reference to the ABO blood group system.
  16. Explain incomplete dominance.
  17. What is co-dominance? Explain with reference to the ABO blood group system.
  18. What is variation? Explain the sources of variation.
  19. Explain continuous and discontinuous variation with examples.
  20. Assess selection as a possible means of evolution.