Reproduction - Section 4.2 Quiz

Which of the following statements about gene mutation is false?

A gene mutation always results in the death of the organism
If a gene sequence of nitrogen bases is CGATA, then an example of a mutated form of the gene sequence might be AGATA
A faulty gene could potentially mutate into a healthy gene
Radiation, such as X-rays or UV rays, is an example of a potential mutagen

To protect the population of B.C. spirit bears (white kermode bears) the black bear population must also be protected. Why?

Black bears also carry the mutated gene that produces white bears
Black bears protect the white bears
If black bears were not protected, the entire population of bears would eventually be white
White bears are born only when there are a substantial number of black bears in a population

Which of the following is an example of a positive mutation?

A human carries a mutated gene that makes that individual resistant to HIV infection
A white bear is produced in the B.C. black bear population
The disease, cystic fibrosis, is caused by any of over 1300 mutations on a single gene
People who carry the sickle cell gene have c-shaped red blood cells that can block blood flow

Which of the following mutations should be classified as a negative mutation?

A change in a gene results in misshaped blood cells that cannot carry oxygen properly
A mutation occurs in a gene for brown hair. Yet that gene still produces brown hair
A base pair is deleted from a strand of junk DNA
A gene mutation produces a healthy cat with six toes

Which of the following is least likely to be a mutagen?

Hypothermia (when the body is cooled below normal temperature)
A biological virus
Second hand cigarette smoke
Sunlight

In gene therapy, in order to be successful, the healthy gene inserted into a target cell must

be able to make the correct amount of the protein needed.
take over and kill the defective gene.
become attached to the cell's ribosomes.
be inserted manually into the cell's Golgi apparatus.

The diagram below illustrates a potential gene therapy for cystic fibrosis.

What is the most likely identity of the structure labeled X in the diagram?

An inactivated cold virus
The cystic fibrosis mutation
A cell nucleus
A droplet of nasal decongestant

Scientists are injecting genes that make the coat protein of hepatitis B virus into young banana trees. Which of the following is not a potential advantage of this experiment?

Banana trees could make antibodies to hepatitis B virus and kill it
Humans that eat the bananas will ingest the virus coat protein and make antibodies to it
Bananas are a potential inexpensive way to deliver a vaccine against hepatitis B
Bananas can be eaten raw, so the coat protein is not deactivated by cooking

Our genes represent about 3 percent of the DNA in our chromosomes. How might such a relatively large amount of junk DNA affect the chances of a mutagen altering a gene's function?

It might decrease the probability of a gene being affected
It might increase the mutagen's effectiveness by increasing the volume of the mutagen's target DNA
It probably has no effect because it does not code for any genes
It would decrease the effectiveness of the mutagen because the junk DNA would repair the gene

Mutations are most often

neutral.
harmful.
beneficial.
deadly.