1. Flower color in the garden pea is due to two interacting genes, A and B. If either gene is recessive (aaB_, A_bb, or aabb) then the phenotype is white. A dominant allele must be present at both genes for flower color to be purple. Among the selfed progeny from the genotype AaBb, what ratio will have purple flowers?

2. What results in a reduction of the number of chromosomes?

3. What is true of sex-linked traits?

4. The haploid chromosome number of Drosophila is n=4. How many autosomes are there in the zygote?

5. A woman discovers that both her parents have Huntington's disease, which is caused by a dominant autosomal allele. What is the chance that she will have the disease?

6. In the following metabolic pathway for anthocyanin (purple coloration) the enzymes A and B are coded for by the dominant alleles at the gene loci A and B, respectively. The A and B loci are not linked, but assort independently. What would be the ratio of green (purple deficient) progeny from the cross AaBb X AaBb?

7. In contrast to meiosis, in mitosis there is/are:

8. A mother has blood type A and a father has blood type B. Their first child has blood type O. What is the chance that their second child will have blood type O?

9. Green colorblindness is a sex-linked recessive trait. In a family, the older son has normal vision, whereas the younger son is colorblind. We can be certain that:

10. Plants with genotype AAbb and aaBB were crossed, and their F₁ progeny were self-pollinated. What ratio of the second generation (F₂) progeny will be aabb?

11. A chi-square was calculated from a genetics experiment, based on a comparison of observed phenotypes with their expected distribution based on Mendelian genetics. The tabular probability level for chi-square was P = 0.20, thus we:

12. In Drosophila, all members of a strain of flies express a jagged wing margin due to a recessive mutation. What experiment can give you evidence to determine if the mutation is sex-linked or autosomal?

1. An adjective describing genetically determined traits which express themselves in both homozygous and heterozygous condition.

4 A species which normally has 23 chromosomes in its gametes.

6 An organism with more than two complete sets of chromosomes.

9 A coat color variation in the female house cat believed to result from random inactivation of an X chromosome early in development.

10 This syndrome is the only human autosomal trisomy in which a significant number of individuals survive longer than a year.

11 A genetic interaction or nonreciprocal masking, e.g., when expressed, the white allele in Drosophila (ww females; and w­ males) always leads to white eyes, regardless of whether they had the sepia allele at a different gene.

14 Homologous ("similar") chromosomes do this, only in meiosis.

15 A form of a gene; new forms arise through mutation.

16 The particle which determines a character in Mendelian genetics.

18 A characteristic of an organism; transmitted from parent to offspring.

19 A stage of cell division when chromosomes have reached the opposite poles, but the cell has not yet divided.

20 A "vehicle" which carries genes, in eukaryotes consisting mainly of DNA and proteins.

1 The condition of having two copies of each chromosome.

2 The heterogametic sex in humans.

3 A chromosome variation involving three complete sets of chromosomes; often results in sterility.

5 This is a structure which contains chromosomes and is a distinguishing feature of eukaryotes.

7 A tabular value used to accept or reject a null hypothesis.

8 A condition giving rise to progeny ratios which would not be predicted on the Mendelian principle of independent assortment of genes during meiosis.

12 All the genes of an organism; also, the allelic condition for a particular gene or genes.

13 The diploid cell from the union of two haploid gametes.

17 The main hypothesis being tested.