genetics homework 4

Question 1

Which sequences are present in both the pre-mRNA and the mature mRNA?

Answer 1

exons, 5’ UTR, 3’ UTR

Question 2

Which sequences are important to predict the protein sequence from the DNA sequence?

Answer 2

start codon, stop codon

Question 3

Which statement about RNA is not true?

Answer 3

RNA is a more stable molecule than DNA.

Question 4

Which class of RNA serves as the coding instruction read by the ribosome to produce a polypeptide chain?

Answer 4

mRNA

Question 5

Which RNA type is found only in eukaryotes?

Answer 5

SnoRNA

Question 6

Which region would not be present in the final RNA transcript?

Answer 6

promoter

Question 7

What are these conserved sequences called?

Answer 7

consensus sequences

Question 8

How is the transcription start site determined in bacteria?

Answer 8

by the binding of RNA polymerase to the consensus sequences of the promoter

Question 9

Which of the subunits does not permanently associate with the enzyme core?

Answer 9

sigma (σ)

Question 10

Which is the most precise definition of a gene?

Answer 10

the entire DNA sequence that is required to transcribe and encode a single RNA molecule

Question 11

What is the Shine–Dalgarno sequence?

Answer 11

the ribosome binding site in bacterial RNA

Question 12

Which is not a characteristic of the 5’ cap?

Answer 12

The 5’ cap is a tag for mRNA degradation.

Question 13

What is the outcome of RNA editing?

Answer 13

The protein translated from the edited mRNA has a sequence different from its gene.

Question 14

Alternative splicing produces

Answer 14

mRNAs of different lengths from the same pre-mRNA.

Question 15

transplicing

Answer 15

This process joins exons from different mRNA molecules, which creates an amino acid sequence that does not correspond to a single gene.

Question 16

alternative splicing

Answer 16

This process produces different mRNA molecules from a single gene, which causes a single gene to produce different proteins.

Question 17

RNA editing

Answer 17

This process adds nucleotides to the pre-mRNA molecule after transcription, which results in an amino acid sequence that does not directly correspond to the original gene sequence.

Question 18

Which RNA sequences can potentially fold to form double-stranded RNA via a hairpin loop?

Answer 18

5′−…..AGUCC…….GGACU……−3′

Question 19

Which statement is most consistent with the one gene, one enzyme hypothesis?

Answer 19

Every gene encodes a separate enzyme.

Question 20

Proteins are composed of amino acids linked together by peptide

Answer 20

peptide

Question 21

Which statement does not help explain these numbers?

Answer 21

The 3’ base of the anticodon on the tRNA can pair weakly with the 5’ codon base.

Question 22

Which statements about the genetic code are most accurate?

Answer 22

The genetic code is generally non overlapping.

Question 23

Which of these is the first step of translation elongation?

Answer 23

A charged tRNA binds to the A site.

Question 24

Which does the termination of translation require?

Answer 24

release factors

Question 25

Primary structure

Answer 25

Amino acid chain

Question 26

Secondary structure

Answer 26

local hydrogen-bond pattern

Question 27

Tertiary structure

Answer 27

three-dimensional structure

Question 28

Quaternary structure

Answer 28

multiple poly-peptide interactions

Question 29

Primary structure: example

Answer 29

N-terminal to C-terminal

Question 30

Secondary structure:example

Answer 30

alpha helices

Question 31

Tertiary structure:example

Answer 31

immunoglobulin domain

Question 32

Quaternary structure:example

Answer 32

hemoglobin complex

Question 33

Using the codon table, what conclusions can be drawn about the genetic code?

Answer 33

many amino acids are encoded by multiple codons. Three codons do not code for amino acids.

Question 34

Which of the options are mechanisms of mRNA surveillance?

Answer 34

no go decay nonsense mediated mRNA decay nonstop mRNA decay

Question 35

What type of cell is represented by the diagram?

Answer 35

bacterial

Question 36

What properties in the diagram indicate the cell type?

Answer 36

Translation and transcription are coupled. The mRNA has a Shine–Dalgarno sequence.