Module 4

Question 1

Which of the following is most likely the number of base pairs in a bacterial chromosome?
4,000,000
4,000
400
40

Answer 1

4,000,000

Question 2

Where are prokaryotic chromosomes located?

Answer 2

In the cytosol

Question 3

What is a plasmid?

Answer 3

Extrachromosomal DNA

Question 4

A histone uses what kind of bond with eukaryotic DNA to stabilize it?

Answer 4

An ionic bond

Question 5

What is found in four forms, each with a deoxyribose sugar, a phosphate and a base?

Answer 5

A nucleotide

Question 6

What molecule functions as a proofreader for newly replicated DNA?

Answer 6

DNA polymerase III

Question 7

What is methylation?

Answer 7

The addition of -CH3 to a cytosine nucleotide after DNA replication

Question 8

In translation, the site where tRNA leaves the ribosome is called what?

Answer 8

The E site

Question 9

Which test uses auxotrophs and liver extract to reveal mutagens?

Answer 9

The Ames test

Question 10

What is the method of DNA repair that involves enzymes that recognize and correct nucleotide errors in unmethylated DNA?

Answer 10

Mismatch repair

Question 11

What are three mechanisms of genetic transfer between cells?

Answer 11

Transduction
Transformation
Conjugation

Question 12

Cells that can take up DNA from their environment are considered?

Answer 12

Competent

Question 13

Conjugation requires what, extending from the surface of a cell?

Answer 13

Sex pilus

Question 14

What are called jumping genes?

Answer 14

Transposons

Question 15

What is the process called when two unrelated cell exchange DNA and incorporate it into their chromosome?

Answer 15

Horizontal gene transfer

Question 16

What does transcription produce?

Answer 16

RNA molecules from DNA molecules

Question 17

What is a nucleotide made of?

Answer 17

A five carbon sugar, a nitrogen base and a phosphate

Question 18

In DNA forms how many hydrogen bonds does adenine share with which other base?

Answer 18

Two hydrogen bonds with thymine

Question 19

A sequence of nucleotides made during replication of a lagging DNA strand is called?

Answer 19

An Okazaki fragment

Question 20

What are the three components of an operon?

Answer 20

1. operator
2. promoter
3. gene

Question 21

repressible operons are important in regulating prokaryotic what?

Answer 21

RNA transcription

Question 22

What is part of each molecule of mRNA?

Answer 22

A codon

Question 23

Ligase plays a major role in what?

Answer 23

The replication of lagging strands

Question 24

What three characteristics must a mutation have before it can affect a population permanently?

Answer 24

It must be lasting, beneficial and inheritable

Question 25

The trp operon is repressible, meaning that it is usually in what state and controlled by what?

Answer 25

it is usually in an active state and controlled by repressor

Question 26

The three steps in RNA transcription are?

Answer 26

1. initiation 2. elongation 3. termination

Question 27

A triplet of mRNA nucleotides that specifies a particular amino acid is called what?

Answer 27

A codon

Question 28

What are the three effects of a point mutation?

Answer 28

1. silence 2. missense 3. nonsense

Question 29

Insertions and deletions in a genetic code are also called what?

Answer 29

Frameshift mutations

Question 30

What kind of operons are inactive until the substrate of their genes' polypeptides is present?

Answer 30

Inducible

Question 31

Why is DNA replication considered semiconservative?

Answer 31

Because a daughter DNA molecule is made of one new strand and one original strand

Question 32

What are nucleotide sequences containing palindromes and genes for proteins that cut DNA strands?

Answer 32

Transposons

Question 33

What is a recombination event that occurs during gamete formation in eukaryotes?

Answer 33

Crossing over

Question 34

What kind of RNA carries amino acids

Answer 34

Transfer RNA (tRNA)

Question 35

What two kinds of RNA are antisense, in that they are complementary to another nucleic acid molecule?

Answer 35

1. Small interfering RNA | 2. Micro RNA

Question 36

What does recombinant DNA technology accomplish?

Answer 36

The modification of an organism's genome

Question 37

What is DNA synthesized from an RNA template?

Answer 37

Complementary DNA

Question 38

After Penicillium were exposed to agents X, Y and Z and examined the type/amount of penicillin the fungi produced to find the most effective. Agents X, Y and Z were probably?

Answer 38

Mutagens

Question 39

What recombinant DNA technique is used to replicate copies of a DNA molecule?

Answer 39

PCR

Question 40

What technique is most useful in following gene expression in a yeast cell?

Answer 40

DNA microarray

Question 41

What do restriction enzymes do?

Answer 41

Cut DNA at a specific nucleotide sequence

Question 42

What application of recombinant DNA technology involves replacing a non-functional, mutated gene with a functional one?

Answer 42

Gene therapy

Question 43

What does a DNA microarray consist of?

Answer 43

Single-stranded DNA localized on a substrate

Question 44

What cuts DNA at specific sites?

Answer 44

Restriction enzymes

Question 45

What process separates molecules based on their size, shape and electrical charge?

Answer 45

Electrophoresis

Question 46

What kind of fusion is often used in the genetic modification of plants?

Answer 46

Protoplast fusion

Question 47

Gel electrophoresis is used in what process?

Answer 47

Southern blotting

Question 48

How do genetic changes help modern bacteria?

Answer 48

1. bacteria have been the recipients of genetic engineering. 2. bacteria can thrive everywhere. 3. bacteria multiply rapidly allowing for genetic changes to appear quickly.

Question 49

A bacterium's genome consists of?

Answer 49

the complete set of genetic information.

Question 50

How does a long circular chromosome fits into a small E. coli cell?

Answer 50

1. by the DNA double helix twisting on itself like a wound-up rubber band 2. by using nucleoid associated proteins for packing 3. by supercoiling

Question 51

The genetic information carried on a plasmid can be used for?

Answer 51

1. bacteriocin synthesis. 2. antibiotic resistance. 3. transfer of genetic material.

Question 52

The base sequence of a messenger RNA molecule that is complementary to the sequence CGTTAGA would be expressed as?

Answer 52

GCAAUCU.

Question 53

Transcription acts to?

Answer 53

produce RNA molecules.

Question 54

Which codon matches to the tRNA anticodon TTT?

Answer 54

No such anticodon exists.

Question 55

An mRNA stop codon codes for?

Answer 55

no amino acid.

Question 56

What are the parts of an operon?

Answer 56

1. Structural genes 2. Operator 3. Promoter

Question 57

The Ames test is used to?

Answer 57

learn whether a chemical can induce a bacterial mutation.

Question 58

Genes that are passed between parent and offspring is called?

Answer 58

vertical gene transfer.

Question 59

Describe a F plasmid

Answer 59

1. They contain genes for production of the pilus 2. They are a double-stranded loop of DNA. 3. They are found in F+ cells.

Question 60

If a donor E. coli cell transfers DNA to a recipient Shigella cell what could happen?

Answer 60

possible transfer of antibiotic resistance

Question 61

A plasmid was produced through genetic engineering that contains a gene for human insulin. Such a plasmid is called a(n)?

Answer 61

recombinant plasmid.

Question 62

To transfer a gene into plants, transposons isolated from which bacteria are used?

Answer 62

Agrobacterium.

Question 63

The mRNA that codes for a particular protein will have ___ nucleotides for each amino acid in the protein.

Answer 63

three

Question 64

Mutations arising from chance events in the environment are known as __________ mutations.

Answer 64

spontaneous

Question 65

The enzyme that seals DNA fragments together is called _______________. (2 word answer)

Answer 65

DNA ligase

Question 66

A ______________ is a substance which induces changes in DNA bases.

Answer 66

mutagen

Question 67

A ________________ is a closed circular piece of DNA that contains few genes which are non-essential to the cell.

Answer 67

plasmid

Question 68

_________ is a useful tool in biotechnology that is a small slide surface on which genes or DNA segments are attached and arranged spatially in a known pattern that can be used to assess gene expression in microorganisms. (2 word answer)

Answer 68

DNA microarray

Question 69

____________ is a technique that takes a segment of DNA and replicates it millions of times in just a few hours.

Answer 69

PCR

Question 70

A cell that is capable of accepting DNA from the environment is called ___________.

Answer 70

competent

Question 71

Cell contact is necessary for bacterial conjugation to occur but does not occur for what?

Answer 71

transduction.