Genetics Test Study Guide

11/16/07

Know definitions for following words:1. pedigree-

tool for tracing a trait through a family2.heterozygous- an organism with two different alleles for a trait3. genotype-

genetic makeup of an organism4. phenotype- physical appearance of an organism5. probability- helps determine the chance that something will

occur

6. incomplete dominance- when an intermediate form is expressed in offspring7. multiple alleles- when more than two alleles control a trait8. polygenic inheritance- when a group of gene pairs act together9. punnett square- a genetics tool that uses letters to represent dominant and recessive alleles10. homozygous- when there are two alleles that are exactly the same11. heredity- passing of traits from parents to offspring

12. dominant factor- a factor that covers up another factor13. recessive factor – a factor that seems to disappear14. alleles- the different forms a gene has for a trait15. genetics- study of heredity16. Homozygous traits will look like two upper case letters or two lower case letters TT ,tt17.Punnett square shows you all the ways

alleles combine

18. Human blood types- A, B, AB and O19. Blood type is controlled by 3 alleles 20. Capital letters stand for and lower case stands for a21. Recessive genetic disorder examples are 22. Mendel called plants that received different alleles for a trait from each parent a23. Father of Genetics is

dominant trait

recessive trait

cystic fibrosis and hemophilia

hybridGregor Mendel

24. Purebred animals that show variations in coat color is an example of

25. Every sex cell has alleles for each trait26. If a human baby has 2- X chromosomes the baby is a ; if it has an X and a Y chromosome it is a 27. A useful segment of DNA is inserted into a bacterium to make28. In, scientists are experimenting with methods to change the arrangement of DNA in a gene

incomplete dominance2

girlboy

recombinant DNAgenetic engineering

29. A purple flower (Pp) and a white flower (pp) could produce purple flowers

30.Describe the advantage of genetically engineered tomatoes. They can be picked green and transported great distances before they ripen completely, so that they are ripe when at the market for purchase

31.If a family has four children, 2 girls, 2 boys, and only one girl and one boy are colorblind, are their parents colorblind?

The father is colorblind

and the mother is a

carrier

x Xc Y

XcX

XcXc XcYXcX XY

2

32. Who is more likely to be colorblind, girls or boys? 33. Offspring with homozygous alleles received how many alleles from each parent? 34. What possible genotypes will the offspring have if the parents’ blood types are O and AB?

boys

one

AO or BO

x A B

O

O AO

AO

BO

BO

32. Who is more likely to be colorblind, girls or boys? 33. Offspring with homozygous alleles received how many alleles from each parent? 34. What possible genotypes will the offspring have if the parents’ blood types are O and AB?

35.Why do cystic fibrosis patients have to have their backs pounded on as part of their therapy? to break the mucus in their lungs to breathe easier

36. One day it will be important for scientists to correct damaged genes in babies before they are born. Why? It may result in a genetic cure for the disorder 37. is one disease that is already being treated by use of recombinant DNA, a method of genetic engineering.

Diabetes

38. You are looking at four purple flowers. What are their phenotypes and genotypes?

Phenotype is purple and just by looking you could not tell their genotypes but it could be PP or Pp

39. is when you select plants or animals with the most desired traits to breed for the next generation.

40. is when a normal allele is placed into a virus, which delivers it when it infects its target

cells.

Selective breeding

Gene therapy

41. Name traits that are a result of polygenic inheritance. human height, human eye color, human skin color, human hair color, grain color in wheat, milk production in cows, egg production in chickens

42. Why was Mendel’s predictions for dominant and recessive traits so accurate?

He worked with a large number of plants (over 30,000) and concentrated on one trait at a time and he kept a record of the results.

43. How can Punnett Squares predict results of crossbreeding in plants?

It shows all the ways in which alleles for a particular trait can be combined

44. How many crosses of red and white four-o’clock flowers would you need to find out all the possible phenotypes for color of flowers? You would need 2, the first cross would be red with white and the second cross would be pink with pink which would give you red, white and pink phenotypes

45. Write a pedigree for a family (parents and four children) in which one girl and one boy are color-blind while one boy and one girl are not.

x Xc YXcX

XcXc XcY

XcX XY

46.If two people are heterozygous for sickle cell anemia, what are the chances that their children will have the disease? S = non sickle cell anemia and s = sickle cell anemia+_______________________________________________________________________________________________________________________________________________________

xS s

S

s

47. Family pedigree of color-blindness. How is the disease inherited?

Disease is sex linked and inherited on the X chromosome. Mother is a carrier.