Deck 5: The Inheritance of Single Gene Traits

Question 1

Fill in the blank. Ploidy refers to the number of sets of chromosomes found in an organism. Most multicellular organisms are _____

Answer 1

diploid

Question 2

The physical outcome - or trait - that results from gene expression is a genotype.

Answer 2

False

Question 3

What term is used for a variety that passes a trait onto all its offspring when crossed to a similar variety?

A) Self-fertile
B) Cross-fertile
C) True-breeding
D) Dominant

Answer 3

True-breeding

Question 4

Which characteristics are true of complex traits? Please select all that apply.

A) Complex traits exhibit continuous variation
B) Complex traits are the result of expression of multiple genes
C) Genes underlying complex traits are inherited in a non-Mendelian fashion
D) Complex traits are true-breeding

Question 5

Match the genetic notations to their definitions.

-strains used to initiate a mating experiment

A) P₀
B) F₁
C) R
D) +

Question 6

Match the genetic notations to their definitions.

-offspring of the initial mating cross

A) P₀
B) F₁
C) R
D) +

Question 7

Match the genetic notations to their definitions.

-dominant allele

A) P₀
B) F₁
C) R
D) +

Question 8

Match the genetic notations to their definitions.

-wild-type allele

A) P₀
B) F₁
C) R
D) +

Question 9

This question relates to Mendel's breeding experiments with peas. A true breeding plant producing smooth peas was crossed with a true-breeding plant producing wrinkled peas (cross 1). The offspring of cross 1 all produced smooth peas. The offspring of cross 1 were then crossed with the wrinkled-pea parent (cross 2). Which of the statements about the cross outcomes are true? Please select all that apply.

A) Half the offspring of cross 2 had smooth peas
B) All the offspring of cross 2 had smooth peas
C) All the offspring of cross 1 had the same genotype
D) The offspring of cross 2 had a 3:1 smooth:wrinkled ratio
E) The wrinkled allele is recessive

Question 10

This question relates to Mendel's breeding experiments with peas. Mendel crossed a true-breeding smooth pea plant with a true-breeding wrinkled pea plant. Mendel then crossed the offspring to each other. Which statements are true about the offspring of the second cross? Please select all that apply.

A) All the offspring had smooth peas
B) Half the offspring had a genotype with 1 recessive and 1 dominant allele
C) Half the offspring had smooth peas
D) The offspring of cross 2 had a 3:1 smooth:wrinkled ratio

Question 11

What term describes a situation where two functional alleles are required for proper biological function

A) Dominant
B) Heterozygous
C) Loss-of-function
D) Haplo-insufficient

Question 12

Match the missing words in the following phrase. In a breeding experiment, a plant with alleles [A] produced white flowers. A plant with alleles a2/a2 produced purple flowers. A cross between these plants produced white flowers with genotype [B]. Therefore, allele a1 was [C] and allele a2 was [D].

Question 13

Fill in the gaps in the Punnett square.
$\begin{array}{|l|l|l|}\hline & \mathrm{T} & {[\mathrm{A}]} \\\hline \mathrm{t} & \mathrm{t}[\mathrm{B}] & \mathrm{tt} \\&\text { tall } & {[\mathrm{C}]} \\\hline \mathrm{t} & \mathrm{tT} & \mathrm{tt} \\& {[\mathrm{D}]} & \text { short } \\\hline\end{array}$

Question 14

The genotype of an organism with a dominant phenotype but unknown genotype can be inferred using a test cross. What genotype should a plant A_ be crossed to in a test cross?

A) A_
B) AA
C) Aa
D) aa

Question 15

In an experiment, you have a tall plant that produces round peas. Tall and round are dominant and the plant is heterozygous for both traits. The plant is then self-fertilized. What is the probability that a single offspring plant is tall and has wrinkled peas? Express your answer as a decimal.

Question 16

Mendel's Law of Segregation refers to the fact that the two alleles for a gene in a diploid organism separate during gamete formation and each gamete receives only one of these alleles.

Question 17

A cross between tall plants (Tt genotype) and short plants (tt genotype) produced 6 offspring. What is the probability that all 6 offspring are tall?

A) 1/2
B) 1/16
C) 1/64
D) 1/128

Question 18

How many offspring plants from a cross between R_ (round peas) and rr (wrinkled peas) genotypes would need to be examined to be confident at the 1% level that the R_ plant is actually RR?

A) 4
B) 7
C) 16
D) 21

Question 19

A tall plant with purple flowers with genotype TtPp was self-fertilized. There were 8 offspring. What is the chance that at least one of the plants was short?

A) 10%
B) 25%
C) 90%
D) 75%

Question 20

What is the term used for the first individual identified in a family to be affected by a phenotype?

A) Pedigree
B) Heterozygote
C) Product
D) Proband

Question 21

Match the letter to the correct description in the pedigree

Question 22

Which of the statements about inheritance of rare traits in pedigrees are true? Please select all that apply.

A) An affected child must have at least one unaffected parent
B) An unaffected child cannot have an affected parent
C) It is assumed that unrelated individuals who join an affected family do not carry the trait
D) Males and females are always equally affected by a rare trait

Question 23

What is the probability that offspring ? is affected?

A) 33%
B) 25%
C) 50%
D) 100%

Question 24

The chi-square test can be used to test genetics hypotheses. For example, it can be used to test the hypothesis that a trait is recessive, in which case two heterozygous parents would be expected to yield 25% homozygous offspring expressing the trait. Large deviations from the expected 25% may indicate the hypothesis is incorrect.
The chi-square equation is as follows:
chi-square = [total of (observed-expected)²] / expected
A cross between two heterozygous tall plants resulted in 136 tall offspring and 36 short offspring. Calculate the chi square value. Give your answer to 2 decimal places.

Question 25

Which of the following characteristics do genes need to possess? Please select all that apply.

A) They must be expressed
B) They must be heritable
C) They must be translated
D) They must be recessive

Question 26

Fill in the blank. If two or more independent events produce the same result, the probability that either will occur is the ____ of their probabilities.

Question 27

A cross between Aa and aa produced four offspring. What is the chance that at least one of the offspring had the recessive phenotype?

A) 1/16
B) 1/4
C) 3/4
D) 15/16

Question 28

In a cross between two heterozygotes, the ratio of genotypes is the same as the ratio of genotypes