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Problem 7.2a
A triplet of mRNA nucleotides that specifies a particular amino acid is called a ____________ .
Problem 7.23a
Ligase plays a major role in ____________ .
a. replication of lagging strands
b. mRNA processing in eukaryotes
c. polypeptide synthesis by ribosomes
d. RNA transcription
Problem 7.24a
Before mutations can affect a population permanently, they must be __________ .
a. lasting
b. inheritable
c. beneficial
d. all of the above
Problem 7.3
The drugs ddC and AZT are used to treat AIDS.
Based on their chemical structures, what is their mode of action?
Problem 7.3a
Three effects of point mutations are ___________ , ___________ , and ____________ .
Problem 7.4a
Polypeptide synthesis requires large amounts of energy. How do cells regulate synthesis to conserve energy? Describe one specific example.
Problem 7.4a
Insertions and deletions in the genetic code are also called ___________ mutations.
Problem 7.5a
An operon consists of __________ , ___________ , and __________ , and is associated with a regulatory gene.
Problem 7.5a
Describe the operon model of gene regulation.
Problem 7.6a
In general, __________ operons are inactive until the substrate of their genes’ polypeptides is present.
Problem 7.7a
Besides the fact that it synthesizes RNA, how does RNA polymerase differ in function from DNA polymerase?
Problem 7.8a
Describe the formation and function of mRNA, rRNA, and tRNA in prokaryotes and eukaryotes.
Problem 7.8a
A gene for antibiotic resistance can move horizontally among bacterial cells by __________ , __________ , and __________ .
Problem 7.9a
Describe how DNA is packaged in both prokaryotes and eukaryotes.
Problem 7.9a
The Ames test ___________.
a. uses auxotrophs and liver extract to reveal mutagens
b. s time intensive and costly
c. involves the isolation of a mutant by eliminating wild-type phenotypes with specific media
d. proves that suspected chemicals are carcinogenic
Problem 8.3a
After scientists exposed cultures of Penicillium to agents X, Y, and Z, they examined the type and amount of penicillin produced by the altered fungi to find the one that is most effective. Agents X, Y, and Z were probably __________ .
a. recombinant cells
b. competent
c. mutagens
d. phages
Problem 8.4a
Describe a CRISPR system and its usefulness.
Problem 8.4a
Indicate which of the following are true and which are false. Rewrite any false statements to make them true by changing the underlined words.
__________ Protoplast fusion is often used in the genetic modification of plants.
Problem 8.8a
The CRISPR-associated enzyme Cas9 __________ .
a. cuts RNA at a specific nucleotide sequence
b. cuts DNA at a specific nucleotide sequence
c. is likely derived from a bacteriophage
d. All of the above are correct.
Problem 12.8a
What is the role of rRNA sequencing in the classification of eukaryotic microbes?
Problem 17
A nucleotide is made of ____________ .
a. A five-carbon sugar
b. Phosphate
c. A nitrogenous base
d. All of the above
Problem 25.1a
A segmented genome is one that has __________.
a. more than one strand of nucleic acid
b. double-stranded RNA
c. both RNA and DNA strands
d. both +ssRNA and -ssRNA molecules
