Lecture 8 Homework

The DNA sequence of the coding strand of a gene is depicted in the top of this figure. Below it are four different types of mutations. Which of them are transversion mutations?

-I -II -III

In this figure, the normal DNA coding sequence of a gene is shown on top, along with four different mutations. Match the mutation to its appropriate description. -I → -II → -III → -IV →

-Silent mutation -Missense mutation -Nonsense mutation -Frameshift mutation

Which of the following statements about promoter mutations is true?

-Up promoter mutations cause the promoter sequence to be more like the consensus sequence -Down promoter mutations decrease the affinity of transcription factors to the promoters

What can cause a frameshift mutation?

-a nucleotide addition -a nucleotide deletion

True or false: Deleterious mutations that cause the death of a cell are called nonsense mutations.

False

A germ-line mutation is one that occurs in ______.

a sperm or egg cell

A mutation occurring in which of the following cells would be termed a somatic mutation?

adult muscle cell

The region where two chromosome pieces break apart and reattach to other chromosome pieces is called a chromosomal __________.

breakpoint

The term germ line is used to describe the ______.

cells that produce sperm and eggs

A mutant Drosophila fly can land on the side of a fly bottle when the bottle is incubated at 20-23o C but not at 24-27o C. This is an example of a(n) ___________ mutation.

conditional

Mutations that affect the phenotype only under certain circumstances are called ______ mutations.

conditional

The addition or deletion of a number of bases that is not a multiple of three causes a(n) __________ mutation.

frameshift

Cells that give rise to the gametes such as egg and sperm are called ____ _____

germ cells

A mutation that occurs directly in a sperm or egg cell, or in one of their precursor cells, is referred to as a(n) ____-____ mutation.

germ line

If an individual possesses a germ-line mutation, then ______ of the gametes produced by the individual will carry the mutation. If an individual possesses a somatic mutation, then ______ of the gametes produced by the individual will carry the mutation.

half; none

A mutant allele is best defined as an allele that ______.

has a different DNA sequence from the wild type

A deleterious mutation that results in the death of an organism is known as a(n) ______ mutation.

lethal

A bse substitution in DNA that ultimately leads to a change in the encoded amino acid is called a(n) ________ mutation.

missense

A mutation in a gene that causes an amino acid change in the encoded protein is called a ________ mutation.

missense

An allele that has a DNA sequence different from that of the wild type is called a(n) ______ allele.

mutant

A heritable change in the genetic material is called a(n) ________.

mutation

An inherited change in the sequence of the genetic material is called a(n) ________.

mutation

A silent mutation is a mutation that results in ______.

no change to the amino acid sequence of the polypeptide

A mutation that results in a premature termination of the synthesis of a polypeptide is called a(n) ________ mutation.

nonsense

Which type of mutation involves a change from a normal codon to a stop codon?

nonsense mutation

A suppressor mutation is so named because it suppresses the ______.

phenotypic effect of another mutation

A change in a single base pair in the genetic material is known as a(n) _____ mutation.

point

A(n) _____ mutation refers to a mutation in which just one base is changed within the DNA sequence.

point

A mutation that does not change the amino acid sequence of a polypeptide is known as a(n) ______ mutation.

silent

Cells of the body other than germ-line cells are called ______ cells.

somatic

Muscle cells, nerve cells, and skin cells are examples of _______ cells.

somatic

Mutations in body cells that do not go on to form gametes are known as _______ mutations.

somatic

A second mutation that occurs in a different site than the first mutation, and which converts the mutant back to the wild-type phenotype, is best referred to as a(n) __________ mutation

suppressor

The embryo on the left carries a germ-line mutation; the one on the right carries a somatic mutation. Which embryo(s) will be able to pass this mutation on to future progeny?

the embryo on the left

The wild type genotype or phenotype is the one that is _________ found in nature.

typically

Mutations that occur in a promoter sequence can be divided into two types: __ promoter mutations increase the transcription rate, while ____ promoter mutations decrease it.

up; down

A breakpoint refers to the region ______.

where two chromosome pieces break and rejoin with other chromosome pieces

In a natural population, the most common genotype is the ____-____ genotype.

wild type

In this figure, the Xs represent mutations in two different protein subunits. The second mutation restores function. What concept does this represent?

intergenic suppression

Suppressor mutation that occur within the same gene as the first mutation as the first mutation are called __________ suppressors.

intragenic

In this figure, the Xs represent amino acids that are altered due to mutations in a transporter gene. In the last panel, transport is restored due to a(n) __________ __________ mutation.

intragenic suppressor

The restoration of functional by a second mutation at a different site in the same gene is known as a(n) ______.

intragenic suppressor