Question Set 2

Assuming independent assortment, what phenotypic ratio would you expect to see if an individual with the genotype RrGg is self-crossed? A 1:3 B 9:3:3:1 C 3:1 D 1:2:1 E 1:3:2:1

B 9:3:3:1

Mendel performed numerous controlled genetic crosses to obtain strains that consistently produced a single phenotype without variation. What are these strains that consistently produce the same phenotype called?

true breeding strains

Crosses in which F1 plants heterozygous for a given allele are crossed to generate a 3:1 phenotypic ratio in the F2 generation are known as A replicate crosses. B dihybrid crosses. C monohybrid crosses. D test crosses. E reciprocal crosses.

Monohybrid crosses

What is the probability of rolling two six-sided dice and obtaining two 4s?

1/36

What is the probability of rolling two six-sided dice and obtaining at least one 3?

11/36

What genotypic ratio would you expect to see among the progeny of a monohybrid cross? 1:3 3:1 9:3:3:1 1:3:2:1 1:2:1

1:2:1

What is the probability of rolling one six-sided die and obtaining a 1 or a 2?

2/6

What is the probability of rolling two six-sided dice and obtaining an odd number on at least one die?

27/36

What is the probability of rolling one six-sided die and obtaining any number but 6?

5/6

Humans have a gene, "T," that is involved in muscle formation of the tongue. Individuals with the one allele can roll their tongues, while individuals with the other allele cannot. If both parents can roll their tongues, but their child cannot, what can be said about the mode of inheritance and what are the genotypes of the parents? A Tongue rolling is dominant, and both parents were heterozygous (Tt). B Tongue rolling is dominant. C Tongue rolling is recessive, and both parents were heterozygous (Tt). D The parents were both homozygous, but the child was heterozygous. E Tongue rolling is recessive.

A Tongue rolling is dominant, and both parents were heterozygous (Tt).

If a trait is X-linked dominant, who would express the trait? A heterozygous dominant females and hemizygous dominant males B homozygous recessive females and hemizygous dominant males C homozygous recessive females and hemizygous recessive males D significantly more females than males E homozygous dominant females and hemizygous recessive males

A heterozygous dominant females and hemizygous dominant males

By convention, when the difference between the observed experimental outcomes and the expected outcome is less than 5 percent (< 0.05), the experimental results are considered to be A statistically significantly different from the expected outcome. B not significant. C within normal expected range. D equal to the mean. E less than one standard deviation from the mean

A statistically significantly different from the expected outcome.

In peas, the yellow allele is dominant over the green allele. If a plant with yellow peas is crossed to a plant with green peas, the resulting plants are 50% yellow and 50% green. What is the genotype of the parents in this cross? A YY × Yy B Yy × yy C YY × yy D yy × yy E Yy × Yy

B Yy × yy

Mendel performed many types of crosses, including those in which the same genotypes are crossed but the sexes of the parents are switched. These are known as A monohybrid crosses. B reciprocal crosses. C replicate crosses. D dihybrid crosses. E test crosses.

B reciprocal crosses.

What phenotypic ratio would you expect as a result of a test cross between a dihybrid organism and one that is homozygous recessive for alleles at two independent loci? A 3:1 B 1:2:1 C 1:1:1:1 D 9:4:2:1 E 9:3:3:1

C 1:1:1:1

Assuming complete dominance, the law of independent assortment would predict that the F2 progeny of F1 heterozygous plants will exhibit a. A 3:1 phenotypic ratio. B 1:2:1 genotypic ratio. C 9:3:3:1 phenotypic ratio. D 9:3:3:1 phenotypic ratio and 1:2:1 genotypic ratio. E 3:1 phenotypic ratio and 1:2:1 genotypic ratio.

C 9:3:3:1 phenotypic ratio

Morgan's analysis of a white-eyed male Drosophila mutation helped explain A independent assortment. B random mutation. C X-linked inheritance. D autosomal dominance. E crossing over.

C X-linked inheritance.

If a trait is X-linked recessive, who would express the trait? A homozygous dominant females and hemizygous recessive males B heterozygous recessive females and hemizygous dominant males C homozygous recessive females and hemizygous recessive males D heterozygous dominant females and hemizygous dominant males E the same proportions of females and males

C homozygous recessive females and hemizygous recessive males

In peas, axial (A) flower position is dominant to terminal (a), tall (L) is dominant to short (l), and yellow (Y) is dominant to green (y). If a plant that is heterozygous for all three traits is allowed to self-fertilize, how many of the offspring would be dominant for all three traits? A 9/64 B 32/64 C 64/64 D 27/64 E 3/64

D 27/64

In peas, axial (A) flower position is dominant to terminal (a), and tall (L) is dominant to short (l). If a plant that is heterozygous for both traits is allowed to self-fertilize, how many of the offspring would also be heterozygous for both traits? A 1/16 B 3/16 C 9/16 D 4/16 E 2/16

D 4/16

What dosage compensation mechanism is employed by female placental mammals? A X nondisjunction B synteny C X chromosome crossing over D X-inactivation E Y-inactivation

D X-inactivation

A couple has four children. What is the probability that they would have four boys? A 1/2 B 1/8 C 1/32 D 1/4 E 1/16

E 1/16

How many possible gametes can be produced by a short plant with yellow, round peas with a heterozygous genotype (YyRrSs)? A 10 B 6 C 12 D 3 E 8

E 8

In peas, the round allele is dominant over the wrinkled allele. If a plant with round peas is crossed to a plant with wrinkled peas, all of the resulting plants have round peas. What is the genotype of the parents in this cross? A Rr × rr B rr × rr C RR × Rr D Rr × Rr E RR × rr

E RR × rr

In a standard monohybrid cross in which one allele is completely dominant to the other, the law of segregation states that the F2 progeny of F1 heterozygous plants will exhibit. A a 9:3:3:1 phenotypic ratio. B a 3:1 phenotypic ratio. C a 1:2:1 genotypic ratio. D a 9:3:3:1 phenotypic ratio and 1:2:1 genotypic ratio. E both a 3:1 phenotypic ratio and a 1:2:1 genotypic ratio.

E both a 3:1 phenotypic ratio and a 1:2:1 genotypic ratio.

What is the mammalian transcription factor that elicits a cascade of gene transcription and developmental events that ultimately produce male internal and external structures?

SRY

A cross between a short pea plant and a tall pea plant results in a 1:1 genotypic and phenotypic ratio in the offspring. What are the genotypes of the parent plants?

Ss ss

In a test cross, a pure-breeding plant is crossed with a plant suspected to be heterozygous (Aa). What is the genotype of the pure-breeding plant?

aa

What type of cross would be used to illustrate Mendel's law of independent assortment?

dihybrid cross

Any mechanism that compensates for differences in the number of copies of genes due to the different chromosome constitutions of males and females is called what?

dosage compensation

Females have two copies of the X chromosome, so they can be homozygous or heterozygous for any genes found on the X chromosome. Males have only one copy of the X chromosome; what term is used to describe this inheritance state?

hemizygous

What simple type of cross that looks at the inheritance of only one trait could be used to illustrate Mendel's law of segregation?

monohybrid cross

According to Bridges's proposal, exceptional phenotypes and unusual karyotypes were the result of rare mistakes in meiosis caused by the failure of X chromosomes to separate properly in either the first or second meiotic division in females. What term is used in referring to this phenomenon?

nondisjunction

An affected individual is born to parents who are unaffected. Is this disorder inherited as a recessive or as a dominant?

recessive