04b: Genetics

Question 1

(X) are the vehicles for genes.

Answer 1

X = chromosomes

Question 2

We have how many pairs of chromosomes?

Answer 2

23 pairs

Question 3

Meiosis produces (haploid/diploid/polyploid) cells.

Answer 3

Haploid (1n)

Question 4

Turner’s syndrome has (X) karyotype, which indicates (extra/missing):

Answer 4

X = XO

Missing sex chromosome

Question 5

A small change in number of chromosomes has what effect on genes?

Answer 5

Changes hundred to thousands of genes

Question 6

Gene mutations can be found in which specific parts of gene?

Answer 6

Anywhere! (Promoter region, exons, introns, etc)

Question 7

In meiosis I, (X) separate. And in meiosis II, (Y) separate.

Answer 7

X = homologous chromosomes

Y = sister chromatids

Question 8

What’s the sum rule?

Answer 8

Determine probability of normal offspring by:

P (homozygous normal) + p (heterozygous normal)

Question 9

What’s the law of independent assortment?

Answer 9

Individual hereditary factors assort independently of each other

Question 10

Is there an exception to law of independent assortment?

Answer 10

Yes - linked genes

Question 11

Describe meiotic recombination.

Answer 11

Shuffling of genetic components between homologs

Question 12

Probability of recombination between two genetic (X) is directly proportional to:

Answer 12

X = loci

Physical distance that separates them on chromosome

Question 13

Two genes closer together are (more/less/equally) likely to undergo recombination than two genes further apart.

Answer 13

Less likely

Question 14

In (X), each genotype has a different phenotype.

Answer 14

X = Incomplete dominance

Question 15

Crossing red and white flowers gives some pink flowers. This is example of:

Answer 15

Incomplete dominance

Question 16

Inheritance of Hyperlipoproteinemia follows rules of incomplete dominance. Heterozygous phenotype would be:

Answer 16

Mild case of disease

Question 17

Give example of Codominance.

Answer 17

Blood type

Question 18

What’s the difference between Codominance and incomplete dominance?

Answer 18

Codominance shows simultaneous expression of both alleles, not a blend of traits.

Question 19

What’s incomplete penetrance?

Answer 19

Having certain genotype means there’s

Question 20

What are phenocopies?

Answer 20

Two different phenotypes that look identical, but one case is inherited while the other is sporadic

Question 21

Albinism is an example of (X), where (Y) gene(s) mutated results in multiple affected systems.

Answer 21

X = pleiotropy

Y = one

Question 22

We must fit (X) length of DNA into a nucleus of what size?

Answer 22

X = 2 m

Nucleus of 6 micrometers

Question 23

Addition of acetyl groups on (X) will (open/close) chromatin. Why?

Answer 23

X = Histone tail

Open;

Neutralizes Lys, decreasing attraction of Histone to DNA backbone

Question 24

T/F: If a methylated DNA strand is replicated, there’s maintenance of methylation on copy strand.

Answer 24

True

Question 25

A (methylated/unmethylated) CpG and (acetylated/deacetylated) Histone gene is OFF.

Answer 25

Methylated; deacetylated

Question 26

A (methylated/unmethylated) CpG and (acetylated/deacetylated) Histone gene is ON.

Answer 26

Unmethylated; acetylated

Question 27

Imprinting refers to:

Answer 27

Genes inherited with different methylation states (from each parent)