The Revision Guide for Student Nurses (Part I)

Terms and Definitions


  1. Define genetics.
  2. Name the scientist who discovered genes.
  3. State the First Law of Genetics.
  4. What is the exception to Mendel's First Law of Genetics?
  5. What is DNA?
  6. Describe the base pairs that form the structure of DNA molecules.
  7. What are chromosomes?
  8. What is the centromere?
  9. Why is it that chromosomes are only visible under the microscope when the cell is dividing?
  10. State the specific number of chromosomes in domestic dogs and cats.
  11. Describe the sex chromosomes.
  12. Since females possess 2 X chromosomes, it follows that they must therefore receive twice the number of genes carried on the X compared to males. In order to compensate for this, only one X chromosome in each cell of a female is activated and contains functional genes. The other X chromosome becomes contracted and contains predominantly inactivated and non-functional genes. This contracted X chromosome may be visible in the nucleus; what is it called?
  13. What are autosomes?
  14. What are homologous chromosomes?
  15. Where are genes located?
  16. What are alleles or allelomorphs?
  17. What are dominant genes?
  18. What are recessive genes?
  19. Give an example of co-dominant genes.
  20. What is meant by a phenotype?
  21. What is meant by a genotype?
  22. What is the difference between homozygous and heterozygous?
  23. What is meant by "incomplete dominance"?
  24. What are sex-linked genes?
  25. What are sex-limited genes?
  26. What is meant by "lethal factors"?
  27. What is meant by "gene mutation"?
  28. What is meant by "epistasis"?