Unit 5: Heredity

Based on the F₂ phenotypic ratio, the inheritance pattern of seed color in this species is best described as

The genotype of the F₁ offspring is most likely

A chi-square test is performed on the F₂ data using a 3:1 expected ratio. Calculate the chi-square value. Round to two decimal places.

If a yellow-seeded F₂ plant is test-crossed with a green-seeded plant and produces approximately equal numbers of yellow and green offspring, the F₂ plant's genotype is

In humans, if a father has blood type AB and a mother has blood type O, which blood types are possible in their children?

Crossing over during meiosis I increases genetic variation by

In Drosophila, the gene for eye color is X-linked. Red eyes (X^R) are dominant over white eyes (X^r). If a heterozygous red-eyed female is crossed with a white-eyed male, what proportion of the female offspring will have white eyes?

The law of independent assortment states that

A pedigree shows that every affected child has at least one affected parent, and the trait appears in every generation. The most likely inheritance pattern is

Two genes, A and B, are on the same chromosome and are 20 map units apart. In a cross AaBb × aabb, what percentage of offspring would be expected to show a recombinant phenotype?

Based on the pedigree, the most likely mode of inheritance for this trait is

What is the probability that an unaffected son in Generation III is a carrier of the trait?

The Generation II daughter married an unaffected male. For the daughter to have affected children, the unaffected male must be

Non-disjunction during meiosis can result in

Incomplete dominance is best demonstrated when

In a monohybrid cross between two heterozygous parents (Aa × Aa), what fraction of the offspring is expected to be homozygous recessive? Express as a decimal.

In a population in Hardy-Weinberg equilibrium, the frequency of the homozygous recessive genotype (aa) is 0.16. What is the frequency of the dominant allele (p)? Express as a decimal.

Epistasis is demonstrated when

Which of the following would violate the Hardy-Weinberg equilibrium?

Based on the cross between two heterozygous parents (RrYy × RrYy), what is the expected phenotypic ratio in the F₂ generation?

The observed results closely match the expected 9:3:3:1 ratio. This supports the conclusion that

If 556 offspring were produced and the expected ratio is 9:3:3:1, how many wrinkled, green offspring are expected? Round to the nearest whole number.

During meiosis, homologous chromosomes separate during

A woman who is a carrier for hemophilia (X^H X^h) has children with a man who has normal blood clotting (X^H Y). What proportion of their sons would be expected to have hemophilia?

Epistasis is demonstrated when

Nondisjunction during meiosis I would result in gametes that

Two genes are located 20 map units apart on the same chromosome. In a testcross involving a heterozygous parent, the expected frequency of recombinant offspring is

In snapdragons, red flower color (C^R C^R) and white flower color (C^W C^W) show incomplete dominance, producing pink heterozygotes (C^R C^W). If two pink snapdragons are crossed, the expected phenotypic ratio of offspring is

A Barr body visible in the nucleus of a cell indicates that

In a cross between two heterozygous individuals (Aa × Aa), what fraction of offspring are expected to be heterozygous? Express as a decimal.

Mendel's Law of Segregation states that

Polygenic inheritance differs from single-gene inheritance in that polygenic traits

Genetic testing reveals that in a population, the frequency of the PKU allele (autosomal recessive) is 0.02. What is the expected carrier frequency in the population, assuming Hardy-Weinberg equilibrium?

A man with type AB blood and a woman with type O blood have children. Which blood types are possible among their offspring?

A student crosses two heterozygous tall pea plants (Tt × Tt) and observes 160 tall and 40 short offspring out of 200 total. The calculated chi-square value is 2.67 with 1 degree of freedom (critical value at p = 0.05 is 3.84). What conclusion is most supported by these results?

Two genes located on the same chromosome show a recombination frequency of 30% in a mapping cross. This indicates that:

In a test cross of a heterozygous tall pea plant (Tt) with a homozygous recessive short plant (tt), what percentage of offspring are expected to be tall? Enter a whole number.

Genetic variation in sexually reproducing organisms is increased by all of the following EXCEPT: