1. What is ‘Genetics’? Genetics is the study of heredity and variations.

2. What is this? DNA molecule Z

3. DNA is found Inside the nuclei of cells

4. A DNA moleculeconsists of 2 polynucleotide chains. The chains run in opposite directions and twist to form a Double helix

5. A DNA molecule contains bases which are G, C, A, T

6. In DNA molecule, base G Pair with C

7. Protein synthesis is in the Cytoplasm

8. In nucleus, genetic codes are copied to RNA

9. DNA control the characteristics of an organism by Forming different protein

10. What is sex chromosomes of individual 3 and 4? 3: XX 4: XY

11. The allele for normal body pigmentation is dominant (D) and the allele for albino is recessive (d). State the genotype of individuals 1, 6, 10, 11 1: Dd 6: Dd 10: dd 11: DD/Dd

12. The allele for normal body pigmentation is dominant (D) and the allele for albino is recessive (d). Explain by means of a genetic diagram, the expected phenotypic ratio of the offspring when individual 7 is married to individual 10. P: dd x dd : Complete by yourself

13. The proteins formed may be (a)used to formed structures of the body, (b)Enzyme which speed up metabolic reactions, and (c)Hormone which regulate physiological processes.

14. The base sequence of a DNA molecule can form the Genetic code

15. How many pairs of chromosome are there in one body cell? 23

16. The 23rd pair of chromosomes determine the sex of an individual and are called the Sex chromosome

17. Sex chromosome in female are XX

18. Sex chromosome in male are XY

19. Female produce only X-bearing egg

20. A fertilized egg will develop into a girl if the egg is fertilized by An X-bearing sperm

21. A fertilized egg will develop into a boy if the egg is fertilized by An Y-bearing sperm

22. Chromosomes are made up of Protein and DNA

23. A gene can exist in two or more alternative forms called Allele

24. An organism genotype contains two identical alleles is called Homozygote

25. An organism genotype contains two different alleles is called Heterozygote

26. What is abnormal with this set of chromosomes? There are 3 chromosomes in chromosome 13

27. Is this person a male or female? Why? Female because there is no Y chromosome

28. What is abnormal with this set of chromosomes? There are 3 sex chromosomes

29. The genotype of Blood group O is ii

30. The genotype of Blood group AB is IAIBIAIB

31. What are the four blood groups in human? A, B, AB and O

32. Tongue rolling is a dominant character in human. The dominant allele for tongue rolling is T and the recessive allele for non-rolling is t. What is the genotype of a non-roller? tt

33. Tongue rolling is a dominant character in human. The dominant allele for tongue rolling is T and the recessive allele for non-rolling is t. What are the possible genotypes of a roller? TT/ Tt

34. A DNA molecule is known to contain 10% adenine (A), what is percentage of thymine (T)? (Hints: A pairs with T and C pairs with G on the two polynucleotide chain of a DNA molecule.) 10%

35. A DNA molecule is known to contain 10% adenine (A), what is percentage of cytosine (C)? (Hints: A pairs with T and C pairs with G on the two polynucleotide chain of a DNA molecule.) 40%

36. A DNA molecule is known to contain 30% adenine (A), what is the ratio of thymine (T) to cytosine (C) in the same molecule? (Hints: A pairs with T and C pairs with G on the two polynucleotide chain of a DNA molecule.) 3:2

37. State the genotype of the individuals 1, 2 and 11, 13. 1: ii 2: I A i 11: I A I A /I A i 13: I A i Z

38. What is the chance of individual 3 and 4 having a boy with blood group O? 12.5% Z

39. What is the chance of individual 1 and 2 having a baby with blood group A? 50% Z

40. Allele which can express in heterozygous condition Is called Dominant

41. Allele which can express in homozygous condition only Is called Recessive