Midterm review 1 Genetics

Question 1

Most genes are HAPLO-sufficient

Answer 1

True

Question 2

LOSS of function mutations in HAPLO-insufficient genes are dominant.

Answer 2

True

Question 3

Huntington disease is due to gene HAPLO-insufficiency

Answer 3

False

Question 4

Siamese cats have dark paws and a light body because they are HETEROZYGOUS for a mutation that affects melanin synthesis.

Answer 4

False

Question 5

The Meiosis 1 metaphase plate has twice the number of chromatids that the mitosis metaphase plate has.

Answer 5

False

Question 6

For homologous to be held together in a tetrad until anaphase of Meiosis 1 requires cohesion of sister chromatid arms.

Answer 6

True

Question 7

HAPLOID cells can undergo mitosis but not Meiosis.

Answer 7

True or False

True for HAPLOID yeast cells

False for HAPLOID human cells

Question 8

An example of codominance is the (O) blood type.

Answer 8

False

Question 9

A woman with Down syndrome (Trisomy 21) marries a man with a normal set of chromosomes. What is the probability that their first child will have Down syndrome?

Answer 9

50%

Or

1/2

Question 10

The Y and G genes are on different CHROMOSOMES and function in a biochemical pathway to produce yellow color in dandelions.

y/y mutants have white flowers, and g/g mutants have white flowers. If you mate y/y parents with g/g parents, what proportion of the F1 progeny do you expect to be white?

Answer 10

0%

Question 11

The Y and G genes are on different CHROMOSOMES and function in a biochemical pathway to produce yellow color in dandelions.

If you mate those F1’s with each other, what proportion of the F2 progeny do you expect to be white?

Answer 11

7/16

Question 12

The Y and G genes are on different CHROMOSOMES and function in a biochemical pathway to produce yellow color in dandelions.

If you instead perform a test cross with the F1 plants, what proportion of the progeny do you expect to be white?

Answer 12

3/4