What is a gene?

2. What is a gene?

3. Answer • Segment of DNA that codes for a specific trait

4. An individual who has two different alleles for a gene is _____________ .

5. Answer • HETEROZYGOUS

6. If an allele does not affect the phenotype of a heterozygous individual, the allele is _________ .

7. Answer • recessive

8. A striped fruit fly is crossed with a non-striped fly. N = non-striped is dominant n = striped is recessive What is the genotype of the striped parent?

9. Answer • nn

10. A striped fruit fly is crossed with a non-striped fly. All 100 offspring are non-striped. N = non-striped is dominant n = striped is recessive What is the genotype of the non-striped parent?

11. Answer • NN

12. What is an allele?

13. Answer • A form of a trait located at a gene. ( gene for blue eyes vs gene for brown eyes)

14. An individual who has two identical alleles for a gene is __________ .

15. Answer • homozygous

16. What does it mean if an allele is dominant?

17. Answer • It prevents (covers up) the other allele (recessive) from being expressed.

18. The ‘B’ gene controls the color of a dog’s coat. The ‘R’ gene controls the texture. Which alleles, B, b, R, and/or r, would occur in all the offspring of the following parents? BbRR x bbRr

19. Answer • R would be in each offspring • b would also be in each offspring

20. The ‘B’ gene controls the color of a dog’s coat. The ‘R’ gene controls the texture. Which trait would occur in all the offspring of the following parents? bbRR x BbRr

21. Answer • ROUGH

22. What types of PEDIGREE is this?

23. Answer • Autosomal dominant

24. What types of PEDIGREE is this?

25. Answer • Autosomal recessive

26. What types of PEDIGREE is this?

27. Answer • X-linked recessive

28. What types of PEDIGREE is this?

29. Answer • X- linked dominant

30. The law of independent assortment describes the inheritance of genes on different chromosomes and the behavior of chromosomes at the beginning of a. meiosis 1 b. meiosis 2 c. mitosis d. all of the above.

31. Answer • Meiosis I

32. In a heterozygous individual, the ______________ allele determines the phenotype.

33. Answer

34. If a heterozygous individual has a phenotype that is intermediate between both types of homozygous individual, the two alleles show _______ _______.

35. Answer • Incomplete dominance

36. Type AB blood is an example of ______________.

37. Answer • 2 co-dominant Alleles • Both A and B are expressed

38. A child has a genetic disease caused by a single gene. Neither parent has the disease. The allele that causes the genetic disease is __________ .

39. Answer

40. An allele of a single gene causes a disease that affects many more males than females. This allele is • autosomal dominant • autosomal recessive • X-linked dominant • X-linked recessive

41. Answer • X-linked recessive

42. A daughter inherits a. more genes from her mother b. more genes from her father c. one copy of each gene from her mother and one copy from her father

43. Answer • C- duh

44. A man who is heterozygous for the albino allele is married to a woman who is homozygous for normal skin color (Aa x AA). What fraction of their children would you expect to be albino?

45. Answer • O %

46. If a son has an X-linked condition (e.g. color blindness or hemophilia), he must have inherited the gene for this condition from his ________.

47. Answer • momma

48. A mother has type O blood and her husband has type AB blood. What blood types can their children have?

49. Answer • AO = type A • BO = type B • AB = type AB • Oo = type o

50. Parents who are both heterozygous for the alleles for albinism (Aa x Aa) have 2 heterozygous children. Now, the mother is expecting fraternal twins. The most likely genotypes for these twins are ___ and ___.