bio test 3

Translation is terminated when a stop codon is presented at the ________ site.

A

mRNA contains three base units of RNA that are called _____, each of which code for one amino acid.

codons

Efficient binding of RNA polymerase

increases the rate of transcription initiation.

DNA, or the instructions for making proteins, is found within the _____ of the cell; while protein synthesis machinery is found in the _____ of the cell.

nucleus; cytoplasm

DNA mutations are passed on to a cell's progeny

true

Arrange the following proteins in the proper order in which they participate in DNA replication. 1 = Primase 2 = Helicase 3 = Single-strand binding proteins 4 = DNA polymerase I

2314

Which of the following is true regarding DNA structure?

Adenine-thymine base pairs form two hydrogen bonds, while guanine-cytosine base pairs form three.

The passage of an mRNA transcript out of the nucleus is a passive, nonspecific process.

FALSE

Which of the following DNA molecules is the most stable?

GCGTGCAC CGCACGTG

At which of the following level(s) can gene expression be regulated in eukaryotes?

passage of mRNA through the nuclear membrane, destruction of the mRNA, and rate of protein synthesi

The correct structure of DNA components can be presented as

phosphate-sugar-base.

The initial tRNA, carrying the first amino acid, occupies the A site on the ribosome.

true

After a tautomeric shift in adenine,

adenine bonds with cytosine.

Place the following steps in the order in which they occur during gene expression.

DNA is transcribed into mRNA in the nucleus, mRNA is carried to ribosomes in the cytoplasm, mRNA is translated into polypeptides by tRNA

A codon is found on the tRNA. It is complementary to the anticodon of mRNA.

False

Translation is the synthesis of

proteins from mRNA.

During the process of translation, mRNA is carried to the ribosome, where it is translated into polypeptides by _____ molecules.

tRNA

A nucleotide deletion in DNA replication

results in a change in the codons in mRNA from the point of the deletion onward, changing the sequence of amino acids inserted into the protein.

A mutation that causes a change in a single nucleotide in DNA

changes the corresponding nucleotide in mRNA, resulting in a different codon.

At which of the following level(s) can gene expression be regulated in eukaryotes?

passage of mRNA through the nuclear membrane, destruction of the mRNA, and rate of protein synthesis

During transcription, double-stranded DNA is transcribed into a complementary molecule of

single-stranded mRNA.

A mutation that changes a single nucleotide can result in a different amino acid being added into a protein.

true

Double-stranded DNA consists of two antiparallel strands, meaning that one strand is oriented in the 5' to 3' direction, while the other is oriented in the 3' to 5' direction.

true

Gene expression can be controlled by altering intron removal and the splicing of exons because this produces different mRNA products.

true

Nucleotide pairing between DNA strands allows the sequence of one strand to determine the sequence of the complementary strand during DNA replication.

true

Which of the following occurs as the ribosome shifts down the mRNA by a distance of three nucleotides?

The tRNA that was in the P site moves into the E site.