Biology '11 Exam 2

Front 1

In the lytic life cycle of phages _________. (19.2)

Back 1

The cell typically dies, releasing many copies of the virus

Front 2

What determines how long a particular mRNA molecule will persist in a eukaryotic cell? (18.2)

Back 2

Nucleotide sequences in the poly-A-tail

Front 3

How do retroviruses, such as HIV, differ from other viruses? (19.2)

Back 3

They contain the enzyme reverse transcriptase

Front 4

Why do flare-ups of herpes virus infection recur through a person's life? (19.2)

Back 4

Herpes-virus can leave its DNA behind as minichromosomes in nerve cell nuclei. Stress can trigger another round of virus production, producing characteristic blisters and sores.

Front 5

Reverse transcription, carried out by retroviruses, is the process by which ______.

Back 5

RNA information is copied into DNA

Front 6

To create recombinant DNA with long-term stability, it is necessary to have which of the following in the test tube? (20.1)

Back 6

DNA ligase

Front 7

Which statement about feedback inhibition is true?

Back 7

---All of these
-It is typically found in anabolic pathways
-The end product of the metabolic pathway controls the activity of first enzyme in the pathway
-It allows a cell to adapt quickly to fluctuations in the availability of important substances
-If the end product accumulates in the cell, the whole pathway is shut down

Front 8

What two enzymes are needed to produce recombinant DNA? (20.1)

Back 8

A restriction enzyme and a ligase

Front 9

A point mutation in which a single base pair is inserted or deleted from DNA is called a(n)_____.

Back 9

Frame-shift mutation

Front 10

The control of gene expression is more complex in multicellular eukaryotes than in prokaryotes because _______. (18.2)

Back 10

In a multicellular eukaryote, different cells are specialized for different funtions

Front 11

During translation in eukaryotic cell _________. (17.4)

Back 11

Polypeptides are synthesized at ribosomes, according to instructions carried by mRNA

Front 12

What is the origin of the phospholipid membrane that envelopes many animal viruses? (19.2)

Back 12

It is "stolen" from the host cell, but it contains some proteins encoded by the viral genome

Front 13

The efficiency of cloning, and the ability to generate healthy cloned animals, has been largely hampered by the difficulty of ________. (20.3)

Back 13

Completely reversing epigenetic alterations in donor cell nuclei such as DNA methylation and chromatin packing

Front 14

In prokaryotic genomes groups of functionally related genes along with their promoters and operators are found together in _______. (18.1)

Back 14

An operon

Front 15

A phage that inserts itself into the host DNA is called ________. (19.2)

Back 15

Lysogenic

Front 16

Which arrangement of the following four enzymes represents the order in which they would be used in a typical gene-cloning experiment resulting in the insertion of a cDNA into a bacterial plasmid? Begin with the gene's mRNA transcript. (20.1)

Back 16

Reverse transcriptase, DNA polymerase, restriction enzyme, DNA ligase

Front 17

Which one of the following enzymes could seal a nick in one strand of a double-stranded DNA molecule by creating a sugar-phosphate bond between the adjacent, unjoined nucleotides? (20.1)

Back 17

DNA ligase

Front 18

In a eukaryotic cell, transcription takes place_______. (17.2)

Back 18

In the nucleus

Front 19

Ultraviolet (UV) radiation is damaging to cells because it _______. (17.5)

Back 19

Causes mutations in the DNA

Front 20

Nuclear transplantation involves _______. (20.3)

Back 20

Removing the nucleus of an egg cell and replacing it with the nucleus of a somatic cell

Front 21

Most human cancers are ________. (18.5)

Back 21

Caused by the accumulation of somatic mutations

Front 22

In an inducible operon, the inducer is often the ____ in the pathway being regulated; the inducer binds to the ______, thus rendering it _____ (18.1)

Back 22

Substrate; repressor; inactive

Front 23

The number of nucleotides bases "read" together on the mRNA to designate each amino acid is _____; this unit is called a(n)_____. (17.1)

Back 23

3; codon

Front 24

The codons AAA, CCC, GGG, and UUU specify the amino acids lysine, proline, glycine, and phenylalanine, respectively. What peptide sequence would be encoded by the sequence 5'-CCCAAATTTGGG-3', if present in the coding strand of the DNA? (17.1)

Back 24

Pro-lys-phe-gly

Front 25

In some cases DNA methylation and histone deacetylation combine to ________. (18.2)

Back 25

Silence certain genes

Front 26

Cell differentiation is first observable when _____. (18.4)

Back 26

mRNAs for tissue-specific proteins appear in a cell

Front 27

Vaccines for viral diseases are ______ and help prevent infection by_______. (19.3)

Back 27

Harmless derivatives of pathogenic viruses; stimulating the immune system to mount a defense against the actual pathogen

Front 28

Which of the following, if any, may be a component of a virus? (19.1)

Back 28

---All of the above
-Protein
-Phospholipid bilayer
-Double-stranded (ds) DNA
-Single-stranded (ss) RNA

Front 29

When a typical restriction enzyme cuts a DNA molecule, the cuts are staggered so that the DNA fragments have single-stranded ends. This is important in recombinant DNA work because _______. (20.1)

Back 29

The fragments will bond to other fragments with complementary single-stranded ends

Front 30

When a virus infects an E. coli cell, what part of the virus enters the bacterial cytoplasm? (19.2)

Back 30

Only the nucleic acid