heredity unit 1 review

Question 1

in snap dragons, heterozygotes for one of the genes have pink flowers, whereas homozygotes have red or white flowers. when plants with red flowers are crossed with plants with white flowers, what proportion of the offspring will have pink flowers?

Answer 1

100%

Question 2

Tallness (T) in snapdragons is dominant to dwarfness (t), while red (R) flower color is dominant to white (r). the heterozygous condition results in pink (Rr) flower color. A swarf, red snapdragon is crossed with a plant homozygous for tallness and white flowers. What are the genotype and phenotype of the F1 individuals?

Answer 2

TtRr- tall and pink

Question 3

in cattle, roan coat co,or occurs in the heterozygous offspring of red and white homozygotes. which of the following corsses would produce offspring in the ratio of 1 red: 2 roan: 1 white?

Answer 3

roan x roan

Question 4

A woman who has blood type A positive has a daughter who is type O and a son who is type B.
which of the following is a possible genotype for the son?

Answer 4

IBi

Question 5

A woman who has blood type A positive has a daughter who is type O and a son who is type B.
which of the following is a possible genotype for the mother?

Answer 5

IAi

Question 6

a man who is an achondroplastic dwarf with normal vision marries a color-blind woman of normal height. the man’s father was 6 feet tall, and both the woman’s parents were of average height. achondroplastic dwarfism is autosomal dominant, and red-green color blindness is X-linked recessive.
how many of their daughters might be expected to be color-blind dwarfs?

Answer 6

none

Question 7

a man who is an achondroplastic dwarf with normal vision marries a color-blind woman of normal height. the man’s father was 6 feet tall, and both the woman’s parents were of average height. achondroplastic dwarfism is autosomal dominant, and red-green color blindness is X-linked recessive.
what proportion of their sons would be color blind and of normal height?

Answer 7

half

Question 8

a man who is an achondroplastic dwarf with normal vision marries a color-blind woman of normal height. the man’s father was 6 feet tall, and both the woman’s parents were of average height. achondroplastic dwarfism is autosomal dominant, and red-green color blindness is X-linked recessive.
hey have a daughter who is a dwarf with normal color vision. what is the possibility that she is heterozygous for both genes?

Answer 8

1.00

Question 9

which of the following statements is true?

Answer 9

the closer two genes are on a chromosome, the lower the probability that a crossover will occur between them

Question 10

a cell that has 2n+1 chromosomes is…

Answer 10

trisomic

Question 11

the frequency of down syndrome in the human population is most closely correlated with which of the following?

Answer 11

age of the mother

Question 12

pea plants were particularly well suited for use in Mendel’s breeding experiments for all of the reasons except…

Answer 12

peas have an unusually long generation time

Question 13

what is the difference between a monohybrid cross and a dihybrid cross?

Answer 13

a monohybrid cross produces a single progeny, whereas a dihybrid cross produces two progeny

Question 14

what was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants?

Answer 14

traits are inherited is discrete units, and are not the result of “blending”

Question 15

how many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE?

Answer 15

8

Question 16

two plants are cross, resulting in offspring with a 3:1 ration for a particular trait. this suggests…

Answer 16

that the parents were both heterozygous

Question 17

when crossing an organism that is homozygous recessive for a single trait with a heterozygote, what is the chance of producing offspring with the homozygous recessive phenotype?

Answer 17

50%

Question 18

black fur in mice is dominant to brown fur. short tails are dominant to long tails. what fraction of the progeny cross BbTt x BBtt will have black fur and long tails?

Answer 18

1/2

Question 19

in cats, black fur is caused by an x-linked allele; the other allele at this locus causes orange color. the heterozygote is tortoiseshell. what kinds of offspring would you expect from the cross of a black female and an orange male?

Answer 19

tortoiseshell female; black male

Question 20

red-green colorblindness is a sex-linked recessive trait in humans. two people with normal color vision have a color-blind son. what are the genotypes of the parents?

Answer 20

XCXc and XCY

Question 21

at which phase is it preferable to obtain chromosomes to prepare a karyotype?

Answer 21

late prophase or metaphase

Question 22

in order for chromosomes to undergo inversion or translocation, which of the following is required?

Answer 22

chromosome breakage and rejoining

Question 23

mitochondrial DNA is primarily involved in coding for proteins needed for electron transport. therefore in which body systems would you expect most mitochondrial gene mutations to be exhibited?

Answer 23

nervous and muscular system

Question 24

similarities and differences in meiosis and mitosis

Answer 24

similiar
- take place in cell nucleus
- both involve cell division
- both have PMAT
- occur in M-stage of cell cycle
- both have synthesis of DNA
different
- mitosis produces two genetically identital daughter cells from single parent cell, uses 100% of parent cell DNA
- meiosis produces 4 genetically unique cells from parent cells and only contain 50% of their DNA
-meiosis uses crossing over and independent assortment
- mitosis involved diploids, meiosis involved haploids
-