Exam 14: Mendel and the Gene Idea

Use the following information to answer the questions below. Radish flowers may be red, purple, or white. A cross between a red-flowered plant and a white-flowered plant yields all-purple offspring. The part of the radish we eat may be oval or long, with long being the dominant characteristic. -In the F₂ generation of the above cross, which of the following phenotypic ratios would be expected?

One of two major forms of a human condition called neurofibromatosis (NF 1)is inherited as a dominant gene, although it may range from mildly to very severely expressed. If a young child is the first in her family to be diagnosed, which of the following is the best explanation?

Mendel accounted for the observation that traits which had disappeared in the F₁ generation reappeared in the F₂ generation by proposing that

Use the following information to answer the questions below. A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Rh positive is a trait that shows simple dominance over Rh negative and is designated by the alleles R and r, respectively. A third gene for the MN blood group has codominant alleles M and N. -If both children are of blood type M, which of the following is possible?

What do we mean when we use the terms monohybrid cross and dihybrid cross?

Hutchinson-Gilford progeria is an exceedingly rare human genetic disorder in which there is very early senility and death, usually from coronary artery disease, at an average age of approximately 13. Patients, who look very old even as children, do not live to reproduce. Which of the following represents the most likely assumption?

Use the following information to answer the questions below. Skin color in a certain species of fish is inherited via a single gene with four different alleles. -One fish of this type has alleles 1 and 3 (S₁S₃)and its mate has alleles 2 and 4 (S₂S₄). If each allele confers a unit of color darkness such that S₁ has one unit, S₂ has two units, and so on, then what proportion of their offspring would be expected to have five units of color?

Refer to the following information to answer the questions below. Gene S controls the sharpness of spines in a type of cactus. Cactuses with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cactuses have dull spines. At the same time, a second gene, N, determines whether or not cactuses have spines. Homozygous recessive nn cactuses have no spines at all. -The relationship between genes S and N is an example of

Which of the following is an example of polygenic inheritance?

Which of the following differentiates between independent assortment and segregation?

Use the following information to answer the questions below. Radish flowers may be red, purple, or white. A cross between a red-flowered plant and a white-flowered plant yields all-purple offspring. The part of the radish we eat may be oval or long, with long being the dominant characteristic. -The flower color trait in radishes is an example of which of the following?

Use the information given here to answer the following questions. Feather color in budgies is determined by two different genes, Y and B, one for pigment on the outside and one for the inside of the feather. YYBB, YyBB, or YYBb is green; yyBB or yyBb is blue; YYbb or Yybb is yellow; and yybb is white. -Two blue budgies were crossed. Over the years, they produced 22 offspring, 5 of which were white. What are the most likely genotypes for the two blue budgies?

In cattle, roan coat color (mixed red and white hairs)occurs in the heterozygous (Rr)offspring of red (RR)and white (rr)homozygotes. Which of the following crosses would produce offspring in the ratio of 1 red:2 roan:1 white?