Fundamentals of Genetics

Study Questions

1.         Briefly describe Mendel’s experiments?

2.         Why did Mendel begin is experiments by allowing pea plants to self germinate for several generations?

3.         What is the difference between the P, F₁, and F₂ generations?

4.         What conclusions did Mendel draw from his results?

5.         Define the terms dominant and recessive.

6.         Describe the Dominance Principle.

7.         According to the Law of Segregation, what happens to the alleles during meiosis?

8.         State the Law of Independent Assortment.

9.         Differentiate between traits and characteristics.

10.       How many factors/alleles determine each characteristic?

11.       Why was Mendel’s work not accepted when it was first published in the 19^th century?

12.       What was Walter Sutton’s contribution to genetics?

13.       What is the Chromosome Theory?

14.       Mendel proposed two factors for each characteristic. What did he call the masking factor?

15.       Compare genotype and phenotype.

16.       For most characteristics, how many alleles affect each characteristic?

17.       Compare homozygous and heterozygous genotypes?

18.       What trait is expressed in the phenotype for a heterozygous genotype?

19.       When is the recessive trait expressed in the phenotype?

20.       Define probability.

21.       You have a deck of cards with the 12 face cards removed. What is the probability of drawing a 5?

22.       What is a Punnet Square?

23.       What is a cross?

24.       Draw a Punnet Square for a cross between AA and Aa.

25.       What is the relationship between genes and alleles?

26.       Define self-pollination.

27.       Name an important aspect of Mendel’s experimental design.

28.       Explain the difference between a monohybrid and a dihybrid cross.

29.       What is the genotype of the F₁ generation of a homozygous to homozygous cross?

30.       What is the phenotype of the F₁ generation of a homozygous to homozygous cross?

31.       What are the genotypes and phenotypes found in the F₂ generation of a homozygous to homozygous cross?

32.       What is the ratio of dominant trait to recessive trait in a heterozygous to heterozygous cross?

33.       Explain how a test cross can determine the genotype of an individual with a dominant trait?

34.       Why does a cross between a red 4 o’clock flower and a white 4 o’clock flower produce a pink flower?

35.       Explain the difference between codominance and incomplete dominance.

36.       Why is it obvious that the genotype of an individual showing recessive trait is homozygous?

37.       In rabbits the allele for black coat (B) is dominant over the allele for brown coat (b). Predict the genotype and the phenotype of a cross between a homozygous black rabbit and a homozygous brown rabbit.

38.       Write the Punnet Square for a dihybrid cross for two individuals that are heterozygous for both traits.

39.       In guinea pigs the allele for rough coat (R) is dominant over the allele for smooth coat (r). In order for all offspring to have smooth coats what would be the genotype of the parents. Show the Punnet Square to support your answer.

40.       You are an explorer who has found a new species of plant. Some of the plants have red flowers and some have yellow flowers. You cross a red flowered plant with a yellow flowered plant and all offspring have orange flowers. Explain your results. How could you prove your hypothesis. Support your answer with a Punnet Square.