Exam 11: Mendelian Patterns of Inheritance

In a case of incomplete dominance, the phenotypic ratio of the F₂ generation is the same as the genotypic ratio.

A testcross involves an individual exhibiting the dominant phenotype but an unknown genotype being crossed with an individual that has a(n) ___________ genotype.

If an individual with a dominant phenotype is crossed with an individual with a recessive phenotype, 4 of their 9 offspring show the recessive phenotype. What is the genotype of the first parent?

Lethal genes (genes that result in the failure to develop a vital organ or metabolic pathway) are nearly always recessive. Animal breeders who discover a unique trait and selectively breed to increase the occurrence of that trait often encounter a noticeable increase in lethal genes. Why?

Which of the following is not part of Mendel's law of segregation?

The F₂ offspring of a classic Mendelian monohybrid cross between homozygous dominant and homozygous recessive parents would produce the genotype(s)

If the probability of event A is 3/4 and the probability of event B is 1/4, then the probability of both A and B occurring at the same time is

What are alleles?

Black and brown guinea pigs are bred. Assuming their color is determined by one gene, and that there is a dominant and a recessive allele, how would you determine which allele is dominant? How could you determine the genotypes of the parents? Explain.

If individuals exhibiting a dominant phenotype are crossed and produce only offspring with the dominant phenotype, what would be the logical genotype of the parents?

In what kind of classic Mendelian cross would you expect to find a ratio of 9:3:3:1 among the F₂ offspring?

Computer simulations are sometimes used to demonstrate the outcome of monohybrid fruit fly crosses, where a student can run generation after generation of fruit flies with 100 offspring produced each generation, half male and half female, and a 3-to-1 phenotype ratio (or 75 to 25) in the F₁ generation. Compared with real genetics results,

Which of the following scenarios would not have been used by Mendel during his research?

Which of the following reasons helped make Mendel successful with his genetic experiments?

Some plants fail to produce chlorophyll, and this trait appears to be recessive. Many plants also self-pollinate. If we locate a pea plant that is heterozygous for this trait, self-pollinate it and harvest seeds, what are the likely phenotypes of these seeds when they germinate?

When crossing a true-breeding red snapdragon flower with a true-breeding white flower of the same species, we secure all pink offspring. This would seem to support the pre-Mendel view that inheritance is a blending of parental traits. However, Mendel and conventional wisdom agree that "blending" of parental traits is not correct and that particles of inheritance are actually involved because

When a round fruit plant is crossed with a long fruit plant their offspring are oval. What is the best explanation for this scenario?

Which allele combination represents a homozygous dominant individual?

If a woman is a carrier for the color-blind recessive allele and her husband is normal, what are their chances that a son will be color-blind?

The offspring of a monohybrid testcross would have what possible genotype(s)?