Exam 29: Heredity

Mitochondrial genes are free of errors. As a result, all genetic problems are due exclusively to nuclear genes.

Delayed action genes can result in fatal diseases.

Among members of the Fuzzy Wuzzy tribe, we will consider two pairs of genes: F = fuzzy hair vs. f = straight hair, and T long hair vs. t = short hair. A homozygous, straight- shorthaired male marries a homozygous, fuzzy- longhaired female (P1 generation). Their offspring (the F1 generation) intermarry and produce progeny (second generation) of four types: fuzzy- longhaired, fuzzy- shorthaired, straight- longhaired, and straight- shorthaired. The results follow a standard dihybrid pattern. -When might amniocentesis be appropriate?

Figure 29.2 Use Figure 29.2 to answer the following: -An allele that completely masks the expression of the other alleles is called .

The folk singer, Woody Guthrie, died of Huntington's chorea. One of his parents also died of this disease affecting the nervous system. The disease usually affects carriers between 25 and 45 years of age and is inherited as a Mendelian autosomal dominant trait. Using Punnett squares, determine the probability that any of the three Guthrie offspring will have this devastating disease.

An example of multiple- allele inheritance is .

Assume that brown eyes (B) are dominant over blue (b); and right- handedness (R) is dominant over left- handedness (r). A brown- eyed, right- handed man marries a blue- eyed, right- handed woman. Their first child is brown- eyed and right- handed, and their second child is blue- eyed and left- handed. What are the genotypes of the parents?

Figure 29.1 -The main way a recessive allele would be expressed even when only one copy is present would be )

Figure 29.1 -In meiosis the spermatozoa that are produced are genetically unlike each other and unlike the cell that produces them. This is one reason for the great variation among humans. What causes this effect?

Figure 29.2 Use Figure 29.2 to answer the following: -Albinism is a good example of a(n) trait.

Figure 29.2 Use Figure 29.2 to answer the following: -Color blindness is a(n) trait.

Figure 29.2 Use Figure 29.2 to answer the following: -Identify, by numbers, any other possible carriers.

is the most common type of fetal testing.

Figure 29.2 Use Figure 29.2 to answer the following: -Is the trait dominant or recessive?

Environmentally produced phenotypes that mimic conditions that may be caused by genetic mutation are called phenocopies.

Among members of the Fuzzy Wuzzy tribe, we will consider two pairs of genes: F = fuzzy hair vs. f = straight hair, and T = long hair vs. t = short hair. A homozygous, straight- shorthaired male marries a homozygous, fuzzy- longhaired female (P1 generation). Their offspring (the F1 generation) intermarry and produce progeny (second generation) of four types: fuzzy- longhaired, fuzzy- shorthaired, straight- longhaired, and straight- shorthaired. The results follow a standard dihybrid pattern. -What is (are) the phenotype(s) of the first- generation offspring?

Figure 29.1 -Given the information in Figure 29.1, if C were an incomplete dominant trait, what would the phenotype ratio be for the offspring?

Some segments of the Y chromosome have no counterpart on the X chromosome.

Inheritance of stature (height) in humans is probably due to .

Among members of the Fuzzy Wuzzy tribe, we will consider two pairs of genes: F = fuzzy hair vs. f = straight hair, and T = long hair vs. t = short hair. A homozygous, straight- shorthaired male marries a homozygous, fuzzy- longhaired female (P1 generation). Their offspring (the F1 generation) intermarry and produce progeny (second generation) of four types: fuzzy- longhaired, fuzzy- shorthaired, straight- longhaired, and straight- shorthaired. The results follow a standard dihybrid pattern. -What would be the gametes of the first- generation individuals?