Chapter 8 Tortora Fall 2024

Question 1

What enzyme transcribes a gene composed of exons and introns to RNA?

Answer 1

RNA polymerase

Question 2

What type of RNA is produced after processing exons and introns?

Answer 2

mRNA

Question 3

What is the function of snRNPs during RNA processing?

Answer 3

Remove intron-derived RNA and splice together exon-derived RNA

Question 4

Where does mature mRNA travel after processing?

Answer 4

Cytoplasm

Question 5

What are codons?

Answer 5

Three nucleotides in mRNA

Question 6

What codon signals the start of translation?

Answer 6

AUG

Question 7

What are the stop codons that signal the end of translation?

Answer 7

• UAA * UAG * UGA

Question 8

What is the P site in translation?

Answer 8

The site where the first tRNA sits

Question 9

What type of bond forms between amino acids during translation?

Answer 9

Peptide bond

Question 10

What happens when the ribosome reaches a stop codon?

Answer 10

The polypeptide is released

Question 11

What is the primary role of RNA polymerase in transcription?

Answer 11

Binds to the promoter and synthesizes RNA

Question 12

What is a gene?

Answer 12

A segment of DNA that encodes a functional product, usually a protein

Question 13

Define genome.

Answer 13

All the genetic information in a cell

Question 14

What is the difference between genotype and phenotype?

Answer 14

Genotype: the genes of an organism; Phenotype: expression of the genes

Question 15

What type of replication occurs in circular bacterial DNA?

Answer 15

Bidirectional replication

Question 16

What initiates DNA synthesis?

Answer 16

An RNA primer

Question 17

What are Okazaki fragments?

Answer 17

Short DNA segments synthesized discontinuously on the lagging strand

Question 18

What is transduction in genetics?

Answer 18

The process of transferring genetic material via bacteriophages

Question 19

What are transposons?

Answer 19

Segments of DNA that move from one location to another in the same or different molecule

Question 20

What are the two types of transduction?

Answer 20

• Generalized transduction * Specialized transduction

Question 21

What is attenuation in the trp operon?

Answer 21

Regulation mechanism based on tryptophan levels affecting transcription

Question 22

What is catabolite repression?

Answer 22

A regulatory mechanism where the presence of glucose inhibits the expression of other operons

Question 23

What are the effects of ionizing radiation on DNA?

Answer 23

Induces breaks in chromosomes

Question 24

What are point mutations?

Answer 24

Mutations that affect a single nucleotide base pair

Question 25

What is the spontaneous mutation rate?

Answer 25

1 in 10^9 replicated base pairs or 1 in 10^6 replicated genes

Question 26

Fill in the blank: Transcription begins when RNA polymerase binds to the _____________ sequence.

Answer 26

promoter

Question 27

Fill in the blank: Transcription proceeds in the _____________ direction.

Answer 27

5' to 3'

Question 28

Fill in the blank: Transcription stops when it reaches the _____________ sequence.

Answer 28

terminator

Question 29

What type of radiation induces breaks in chromosomes?

Answer 29

Ionizing radiation

Question 30

Nonionizing radiation induces _______ dimers.

Answer 30

[thymine]

Question 31

What are nucleotide analogs known to disrupt?

Answer 31

DNA and RNA replication

Question 32

Nucleotide-altering chemicals result in what type of mutations?

Answer 32

* Base-pair substitution mutations * Missense mutations

Question 33

What do frameshift mutagens result in?

Answer 33

Nonsense mutations

Question 34

What is the spontaneous mutation rate per replicated base pairs?

Answer 34

1 in 10^9

Question 35

What is the spontaneous mutation rate per replicated genes?

Answer 35

1 in 10^6

Question 36

Mutagens increase the mutation rate to what range per replicated gene?

Answer 36

* 10^-5 * 10^-3

Question 37

What did Griffith's experiment demonstrate?

Answer 37

Genetic transformation

Question 38

What type of bacteria was isolated from dead mice in Griffith's experiment?

Answer 38

Encapsulated bacteria

Question 39

What happened to mice injected with living nonencapsulated bacteria?

Answer 39

They remained healthy

Question 40

What was the result of injecting heat-killed encapsulated bacteria into mice?

Answer 40

No colonies were isolated

Question 41

What occurs during bacterial transformation?

Answer 41

* Donor DNA aligns with complementary bases * Recipient cell takes up donor DNA * Recombination occurs between donor DNA and recipient DNA

Question 42

What is the first step in the mechanism of genetic transformation in bacteria?

Answer 42

Recipient cell takes up donor DNA

Question 43

What are the DNA fragments from donor cells used for in transformation?

Answer 43

They align with complementary bases in the recipient DNA

Question 44

True or False: All animations in the presentation will appear in Normal or Slide Sorter views.

Answer 44

False

Question 45

What is required for most animations to appear in the presentation?

Answer 45

Latest version of Flash Player