A possible sequence of nucleotides in DNA that would code for the polypeptide sequence Phe-Leu-Lie-Val would be

A possible sequence of nucleotides in DNA that would code for the polypeptide sequence Phe-Leu-Lie-Val would be

a. 5' TTG-CTA-CAG-TAG 3'

b. 3' AAC-GAC-GUC-AUA 5'

c. 3' AAA-AAT-ATA-ACA 5'

d. 3' AAA-GAA-TAA-CAA 5'

Answer: D

A frameshift mutation could result from

A frameshift mutation could result from

a. a base insertion only.

b. a base deletion only.

c. a base substitution only.

d. deletion of three consecutive bases.

e. either an insertion or a deletion of a base.

Answer: E

With each replication of the DNA molecule, the DNA molecule becomes shorter.

With each replication of the DNA molecule, the DNA molecule becomes shorter.

a. This is best explained by the fact that DNA polymerase can only add nucleotides to the 5' end

b. This problem is resolved by telomerase, which extends the 3' end of the DNA

c. This is not a problem because the telomere is a nonessential repeating unit

d. This is true only if the organism has been exposed to excessive amounts of ultraviolet radiation

e. This is due to the fact that thymine dimers cause DNA to buckle and interfere with DNA replication

Answer: B

In DNA, the designations 3' and 5' refer to the

In DNA, the designations 3' and 5' refer to the

a. bonds formed between phosphate groups and carbon atoms of deoxyribose.

b. carbon or nitrogen atoms on the rings of purine or pyrimidines.

c. cross-linking of the third and fifth carbon atoms of deoxyribose.

d. bonding between purines and deoxyribose and between pyrimidines and deoxyribose.

e. bonds that form between adenine and thymine and between guanine and cytosine.

Answer: A

The 3' Poly-A tail is attached to

The 3' Poly-A tail is attached to

a. the Poly-A polymerase enzyme.

b. the mRNA.

c. the tRNA.

d. the coding strand of the DNA molecule.

e. the template strand of the DNA molecule.

Answer: B

Eukaryotic mRNA molecules are occasionally interspersed with non-coding sequences that must be removed before protein synthesis. These are called

Eukaryotic mRNA molecules are occasionally interspersed with non-coding sequences that must be removed before protein synthesis. These are called

a. anticodons.

b. introns.

c. exons.

d. nucleosomes.

e. chromomeres.





Answer: E