Practice Exam #2

Question 1

Transfer ribonucleic acid (tRNA) is a type of RNA molecule that helps decode a messenger RNA by…

Answer 1

Providing the anticodon in one end and an specific amino acids on the other end of the molecule

Question 2

Gene expression is regulated at different levels. What is an example of transcriptional regulation?

Answer 2

A cap at the 5’ end and tail at the 3’ end are added to the RNA

Question 3

What is false when describing restriction enzymes and ligases?

Answer 3

Ligases cut DNA and Restriction enzymes join DNA fragments

Question 4

Before Darwin published his work, Lamarck and others had suggested mechanisms for evolution. By what means did Darwin propose species evolved over time?

Answer 4

Natural selection

Question 5

In what way(s) can mRNAs be processed?

Answer 5

1. By removing the introns (the noncoding regions) of the mRNAs
2. By adding caps and tails to the ends of the mRNAs
3. By splicing the exons (the coding regions) of the mRNAs in different ways

Question 6

DNA polymerase binds to specific regions in the DNA before DNA replication takes place. This regions are called…

Answer 6

Origin of replications

Question 7

Why can a person who is unable to produce insulin be successfully treated with insulin derived from genetically modified bacteria?

Answer 7

The gene that produces insulin in humans was inserted into the bacteria where it continues to
produce human insulin.

Question 8

What is the gender and color of a calico cat whose genotype is XBXB; where “B” is the dominant allele for black color and “X” is the sex chromosome?

Answer 8

Female, black

Question 9

The oldest fossils typically are found in the ________ sediments.

Answer 9

lower

Question 10

After PCR, gel electrophoresis is performed. Which direction does the PCR product migrate towards?

Answer 10

the positive (+) pole because DNA is negatively charged

Question 11

What is not a target for DNA profilers?

Answer 11

Coding regions in the genome

Question 12

The difference between cDNA and DNA is that…

Answer 12

cDNA does not contain introns

Question 13

In many ways, a mule is a superior animal to the horse or donkey. Mules are often stronger and can jump higher than either of their parents. Why, then, are mules considered to be a “weak hybrid”?

Answer 13

They are sterile.