Exam 4: Gene Interaction

IA and IB alleles exhibit ________ (complete or incomplete)dominance over the i allele.

Two pure-breeding mutant plants produce white flowers. When they are crossed, all of the progeny have wild-type purple flowers. What does this genetic complementation tell you?

To better understand which genes are involved in developmental pathways, geneticists use experimental analyses of mutant phenotypes. What is this analytic approach called?

Mendel studied tall and short pure-breeding lines of pea plants. Inherited genetic variation would dictate that one line would produce tall plants and the other short plants, but the genes and phenotypes are influenced by what external factor?

The 9:6:1 ratio seen in the dihybrid cross of summer squash indicates what genetic relationship between the two genes controlling fruit shape?

Individuals with blood type A have which blood antigen(s)?

A mutation resulting in an inactive gene product is classified as __________.

A metabolic reaction requires 10 units of enzymatic activity to proceed. If a dominant allele D can generate 8 units of enzyme and a recessive allele d can generate 2 units of enzyme, what can be said of the dominant wild-type allele?

An individual who is a "universal acceptor," meaning he or she will not have an adverse reaction to a transfusion with any type of blood, has which blood type?

The four different human blood types are caused by how many different alleles? What are the alleles?

What type of allele is often detected as a distortion in segregation ratios, where one class of expected progeny is missing?

Which type of pathway is responsible for melanin production: a biosynthetic pathway, signal transduction pathway, or developmental pathway?

A metabolic reaction requires 40 units of enzymatic activity to proceed. If a dominant allele D can generate 40 units of enzyme and a mutant allele d" generates 20 units of enzyme, what can be said of the dominant wild-type allele?

Deafness is caused by recessive mutations in any one of at least five genes. Two deaf individuals have nine children, all of whom have normal hearing. Which of the following can you conclude?

If an organism with a particular genotype fails to produce the corresponding phenotype, the organism is said to be ________ for the trait.

Most people with the dominant mutant polydactyly allele have extra digits, but at least 25% have the normal number of digits. What is the genetic explanation for this observation?

Alleles of the Sbe1 gene, which controls pea shape, can be detected by DNA analysis. In heterozygous plants, two distinct bands of DNA are visible. What is the relationship between the alleles of the heterozygote at the molecular level?

In familial hypercholesterolemia, individuals who are homozygous for the mutation lack LDL cholesterol receptors in the liver, causing high levels of serum cholesterol. This is a defect in which type of gene pathway: a biosynthetic, signal transduction, or developmental pathway?

The amount of enzyme activity in a cell that is homozygous for a mutant allele is 0 units. The amount of enzyme activity in a cell homozygous for the WT allele is 200 units. The amount of enzyme activity in a heterozygote is 0 units. What type of allele is the mutant allele?

Proper cross-matching of blood type is essential for safe blood transfusion. What is the general rule for safe blood transfusion, and what are the consequences if a patient receives the incorrect blood type by accident? If a patient's blood type is unknown, what is the safest course of action?