Question 1

Color blindness is a recessive X-linked trait.A normal couple has a color-blind child.Who else in this family is probably color blind?

Accepted Answer

A) the child's maternal grandfather 
B) the child's maternal grandmother 
C) the child's paternal grandfather 
D) the child's paternal grandmother 
E) the child's maternal grandmother or grandfather

Question 2

You see a recombination frequency of 0.3%.What does this indicate?

Accepted Answer

A) That the genes are located close together on the same chromosome 
B) That the genes are on different chromosomes 
C) That the genes are assorting independently most of the time 
D) That the offspring has a large number of non-parental phenotypes 
E) That the genes are located on the same chromosome,but very far apart

Question 3

In goats,the gene for coat color is on an autosome and light brown color is dominant to black.A light brown male is mated to a black female,producing a black kid (baby goat).If they produce another kid,could it be light brown? If so,what are the chances of it being light brown?

Accepted Answer

A) No,since the black allele is present all offspring will be black 
B) Yes,100% since the first kid was black the next one has to be light brown 
C) Yes,75% since light brown is dominant 
D) Yes,50% as the male must be heterozygous for color 
E) Yes,but it will depend on whether the kid is male or female

Question 4

Two identical twins were separated at birth,one grew up in a prosperous home with ample food and time for rest.The other twin was tragically abandoned and grew up in and out of foster homes and living on the streets.After more than 20 years,the two twins were reunited,but despite their identical genomes,the twins looked very different.The most noticeable difference was their difference in stature,the prosperous twin was tall and well built,while the abandoned twin was short and scrawny.How can you explain these differences?

Accepted Answer

A) The twins actually have different genotypes. 
B) The poor twin was undernourished as a child,and as a result his genes that control height and stature were mutated,resulting in a different phenotype. 
C) The poor twin was undernourished as a child,and as a result he was unable to reach the full potential of his genes. 
D) Traits such as height and stature are are not controlled by a person's genes,rather they are determined by environmental factors,such as nutrition,rest,and exercise. 
E) Twins often have different phenotypes,because one twin gets more resources in the womb than the other.

Question 5

The Xist gene product

Accepted Answer

A) is never translated into protein. 
B) is required for the production of Barr bodies. 
C) coats the X chromosome with RNA. 
D) associates with proteins to compact the chromosome. 
E) All of these statements are correct.

Question 6

If a plant species exhibits maternal inheritance for leaf pigmentation,what is the phenotype of the parents of a variegated (green and white leaves)plant?

Accepted Answer

A) The maternal plant must be white and the paternal plant must be green. 
B) The maternal plant must be green and the paternal plant must be white. 
C) The maternal plant must be variegated and the paternal plant can be any color. 
D) Both the maternal and paternal plant must be variegateD. 
E) The maternal plant must be variegated and the paternal plant must be whitE.

Question 7

An organism has one Z chromosome and one W chromosome.That organism is

Accepted Answer

A) a female bird. 
B) a male bird. 
C) a female insect. 
D) a male insect. 
E) a male or female human.

Question 8

The single-factor crosses performed by Mendel support the observation that

Accepted Answer

A) the two alleles for a given gene are distributed randomly among an individual's gametes. 
B) the two alleles for a given gene are found within the same gamete. 
C) if the recessive alleles for two different genes are on the same chromosome,they will never be found within the same gamete. 
D) only the dominant alleles for a given trait are found in an organism's gametes. 
E) if the dominant alleles for two different genes are on different chromosomes,they will never be found within the same gametE.

Question 9

The actions of Xist result in an organism that is a phenotypic mosaic.

Accepted Answer

A) True 
 B)False

Question 10

_________ occurs when 50% of a protein produces a different phenotype than that produced by 100% or 0% of the protein.

Accepted Answer

A) Incomplete dominance 
B) Recessive inheritance 
C) Codominance 
D) Loss of function mutation 
E) Hybridization

Question 11

When a single-gene mutation can have phenotypic effects at multiple stages of development,it is

Accepted Answer

A) pleiotropic. 
B) incompletely dominant. 
C) recessive. 
D) causing a disease. 
E) X-linked.

Question 12

You are trying to improve growth in an economically important fish species.These fish have a gene that controls their size.There are two size alleles;L and S.You cross a large female (LL)with a small male (SS)and get all large fish! The genotypes of the F1 are 100% LS so you assume that large size is dominant to small.You then cross a small female (SS)with a large male (LL)and get all small fish! The genotypes of this F1 are all LS.How do you explain this result?

Accepted Answer

A) The gene for large size is a maternal effect gene. 
B) L is not dominant to S. 
C) The gene for large size is a sex-linked gene. 
D) L is dominant to S. 
E) The gene for large size is a maternal effect gene and L is dominant to S.

Question 13

Barr bodies are a diagnostic feature of X inactivation.

Accepted Answer

A) True 
 B)False

Question 14

Epigenetic inheritance

Accepted Answer

A) only refers to autosomal genes. 
B) only effects female offspring. 
C) only effects male offspring. 
D) can result in the expression of different alleles in different generations. 
E) only refers to X inactivation.

Question 15

In cats,the gene for coat color is found on the X chromosome.Shown below is a mass of cells making up an early female cat embryo.The X chromosomes are shown in each cell;this embryo has one orange coat color allele (O)and one black coat color allele (B).Which of the following is ACCURATE about this embryo?

Accepted Answer

A) It will give rise to a calico cat 
B) It will give rise to a black cat,because black is dominant to orange 
C) It will give rise to an orange cat,as the paternal chromosomes carrying the black allele will be inactivated 
D) Since it is heterozygous,it will give rise to a cat with two Barr bodies in each cell 
E) Since it is heterozygous,it will give rise to a calico cat with two Barr bodies in each cell

Question 16

A cross between two pea plants results in 732 purple and 268 white plants.What is (are)the genotype(s)and phenotype(s)of the parents that produced these offspring?

Accepted Answer

A) both parents are heterozygous purple 
B) one parent is homozygous purple,second parent is homozygous white 
C) one parent is heterozygous purple,second parent is heterozygous white 
D) one parent heterozygous purple,second parent homozygous white 
E) one parent is homozygous purple,second parent is heterozygous white

Question 17

What is a testcross?

Accepted Answer

A) Any genetics cross you do in order to test a hypothesis. 
B) Any genetics cross you see on an exam 
C) A cross between two organisms of different species 
D) A cross between an organism of unknown genotype with a homozygous recessive individual 
E) A cross between two true-breeding individual (such as we see in the P generation)

Question 18

Offspring receive both the alleles for a given trait from one parent.

Accepted Answer

A) True 
 B)False

Question 19

Extranuclear inheritance was first described by Carl Correns based on his observations of Mirabilis jalapa (the four o'clock plant).M.jalapa can have either white,variegated (white and green)or green leaves.Pollen from a variegated M.jalapa plant is used to fertilize a white M.jalapa flower.Which of the following phenotypes would you expect to see in the offspring of this cross?

Accepted Answer

A) White 
B) Green 
C) Variegated 
D) White and variegated 
E) White,green,and variegated

Question 20

An organism that is heterozygous for two traits can produce a maximum of _______ different gametes for these traits.

Accepted Answer

A) 2 
B) 4 
C) 2;if they are on the same chromosome 
D) 27 
E) 8

Exam 14: Patterns of Inheritance

Color blindness is a recessive X-linked trait.A normal couple has a color-blind child.Who else in this family is probably color blind?

You see a recombination frequency of 0.3%.What does this indicate?

In goats,the gene for coat color is on an autosome and light brown color is dominant to black.A light brown male is mated to a black female,producing a black kid (baby goat) .If they produce another kid,could it be light brown? If so,what are the chances of it being light brown?

The Xist gene product

If a plant species exhibits maternal inheritance for leaf pigmentation,what is the phenotype of the parents of a variegated (green and white leaves) plant?

An organism has one Z chromosome and one W chromosome.That organism is

The single-factor crosses performed by Mendel support the observation that

The actions of Xist result in an organism that is a phenotypic mosaic.

_________ occurs when 50% of a protein produces a different phenotype than that produced by 100% or 0% of the protein.

When a single-gene mutation can have phenotypic effects at multiple stages of development,it is

Barr bodies are a diagnostic feature of X inactivation.

Epigenetic inheritance

A cross between two pea plants results in 732 purple and 268 white plants.What is (are) the genotype(s) and phenotype(s) of the parents that produced these offspring?

What is a testcross?

Offspring receive both the alleles for a given trait from one parent.

An organism that is heterozygous for two traits can produce a maximum of _______ different gametes for these traits.