Cell Cycle Intro and DNA Replication + PCR and Genome Variation

The estimated number of genes in the human genome is: 15,000. 250,000. 400,000. 25,000. 40,000.

25,000

Approximately what percentage of the human genome consists of repetitive DNA or transposable elements? 25 percent 5 percent 50 percent 10 percent 1 percent

50 percent

Only 2.5 percent of the human genome actually codes for proteins. The other 97.5 percent includes: repetitive DNA. templates for noncoding RNA. introns. All of other answer options are correct.

All of other answer options are correct.

What is the benefit of using Taq polymerase in PCR? - Because it is taken from bacteria that live in high temperatures, it does not have a proofreading function. - Because it is taken from bacteria, this enzyme works much more efficiently than other types of DNA polymerase. - None of the answer options is correct. - Because it is taken from bacteria that live in high temperatures, it stays active during denaturation steps of the reaction. - Because it is taken from bacteria, it makes fewer mistakes.

Because it is taken from bacteria that live in high temperatures, it stays active during denaturation steps of the reaction.

RNA primase lays down an RNA primer to start DNA replication. If a mutation occurs that blocks the function of RNA primase, which synthesis of which strand is affected, and why? - Both strands are affected because all DNA polymerase can only add new nucleotides to a 3′-OH present at the end of the RNA primer. - The leading strand is affected because it leads DNA synthesis. - The lagging strand is affected because it requires an RNA primer for each Okazaki fragment produced.

Both strands are affected because all DNA polymerase can only add new nucleotides to a 3′-OH present at the end of the RNA primer.

Which of the strands use a template for DNA replication? - the lagging strand - the leading strand - Both strands use a template during DNA replication.

Both strands use a template during DNA replication.

The enzyme responsible for joining Okazaki fragments together during DNA replication is: - topoisomerase II. - DNA ligase. - helicase. - DNA replicase. - DNA polymerase.

DNA ligase.

Why are primers needed for DNA replication? - They help direct the placement of the telomeres. - The primers help with the proofreading function of DNA polymerase. - A tiny amount of RNA is needed to tell the cell where genes are located. - DNA polymerase can only add nucleotides to an existing chain. - They help with the joining of Okazaki fragments.

DNA polymerase can only add nucleotides to an existing chain.

The correct sequence of steps in the eukaryotic cell cycle is: - G1→ S phase → G2→ mitosis → cytokinesis. - G0→ S phase → G1→ S phase → G2→ cytokinesis → mitosis. - G1→ S phase → G2→ cytokinesis → mitosis. - G0→ S phase → G1→ S phase → G2→ mitosis → cytokinesis. - G0→ S phase → G1→ G2→cytokinesis → mitosis.

G1→ S phase → G2→ mitosis → cytokinesis.

Which does not occur after an incorrect base is removed by DNA polymerase? - Polymerase activity is restored. - The template and daughter strands are separated by helicase activity. - The correct nucleotides are moved into place and attached. - New nucleotides are incorporated into the growing daughter strand.

The template and daughter strands are separated by helicase activity.

Why are telomeres a necessary component of linear chromosomes? - They direct where DNA synthesis will end. - None of the answer options is correct. - They fix mistakes that are made during DNA replication. - They maintain the length of a chromosome because DNA is shortened every time it is replicated. - They direct where DNA synthesis will begin.

They maintain the length of a chromosome because DNA is shortened every time it is replicated.

Which statement about DNA replication is true? - The lagging strand requires an RNA primer to initiate DNA synthesis, whereas the leading strand does not require an RNA primer. - On the leading strand, new DNA is added to the 3′ end of the growing strand, whereas on the lagging strand, new DNA is added to the 5′ end. - DNA polymerase performs DNA synthesis on the leading strand, and RNA polymerase performs synthesis on the lagging strand. - When DNA polymerase reaches a primer from prior DNA synthesis, the primer is removed and replaced with DNA.

When DNA polymerase reaches a primer from prior DNA synthesis, the primer is removed and replaced with DNA.

Select the correct order of steps during PCR. - initiation, extension, termination - denaturation, annealing, extension - annealing, initiation, termination - denaturation, extension, termination - initiation, denaturation, extension

denaturation, annealing, extension

The C-value paradox applies to: viruses. archaea. eukaryotes. bacteria. All of these choices are correct.

eukaryotes.

What is the name for the enzyme activity that DNA polymerase has when it removes an improperly paired base from the end of the growing strand? - exonuclease activity - polymerase activity - endonuclease activity - helicase activity

exonuclease activity

Organisms that have bigger genomes are more complex than organisms with smaller genomes. true false

false

The complexity of an organism is proportional to the number of genes in its genome. false true

false

Telomerase is fully active in _____ and _____ cells, but almost completely inactive in _____ cells. somatic; blood; germ germ; stem; somatic stem; blood; germ germ; somatic; stem somatic; germ; stem

germ; stem; somatic

In contrast to linear DNA replication, circular DNA replication typically: - All of these choices are correct. - does not produce Okazaki fragments. - has a single origin of replication. - does not produce a replication bubble. - occurs only at a single replication fork.

has a single origin of replication.

What is the name of the enzyme that separates the two strands of DNA during replication? DNA polymerase primase topoisomerase helicase DNA ligase

helicase

The C-value paradox states that genome size: - is negatively correlated with the complexity of the organism. - is positively correlated with the complexity of the organism. - is uncorrelated with the complexity of the organism. - differs in reproductive cells and nonreproductive cells.

is uncorrelated with the complexity of the organism.

A eukaryotic chromosome has _____ origin(s) of replication, and a bacterial chromosome has ______ origin(s) of replication. one; one one; many many; one many; many

many; one

The division of genetic material in a eukaryotic cell is called: replication. binary fission. cytokinesis. mitosis.

mitosis

The polymerase chain reaction (PCR) is used to generate: - multiple copies of whole chromosomes and a targeted region of DNA. - multiple copies of a targeted region of DNA.single copies of whole chromosomes. - a single copy of a targeted region of DNA.multiple copies of whole chromosomes.

multiple copies of a targeted region of DNA.

As a piece of linear DNA is replicated, the leading strand will have _____ RNA primer(s) and the lagging strand will have _____ RNA primer(s). one; many many; many many; one one; one

one; many

Having more than two sets of chromosomes in a genome is called: extraploidy. aneuploidy. diploidy. polyploidy. haploidy.

polyploidy.

What is the process of "proofreading" by DNA polymerase? - changing the DNA sequence to produce improved protein structures - re-replicating a template of DNA for a second time - removing an improperly paired base and replacing it with the proper one - removing introns from the sequence and joining exons to each other

removing an improperly paired base and replacing it with the proper one

Which of the choices is not needed for DNA replication? - None of the answer options is correct. - DNA - nucleotides - enzymes - ribosomes

ribosomes

When DNA with tandem repeats is visualized on a gel, the resulting fragments separate according to their: size. shape. color. A-T content. G-C content.

size

If you were able to find a drug that could inhibit the reactivation of telomerase activity in cancer cells, the cancer cells would: - become less invasive. - slowly erode their chromosome ends. - stop dividing immediately. - gradually revert to normal cells. - eventually die from lack of energy.

slowly erode their chromosome ends. Cancer cells acquire unlimited replicative potential because they reactivate their telomerase.

In DNA replication, each individual parent strand acts as a _____ strand for the synthesis of a _____ strand. daughter; template template; duplicate template; daughter duplicate; daughter daughter; duplicate

template; daughter

A match between the DNA in a sample and the genomic DNA of a particular individual for a single tandem repeat site is not sufficient to establish identity. However, a mismatch is definitive. The primary reason is that: - the sample might have been contaminated. - the DNA in the sample must match its origin. - variable number tandem repeats (VNTRs) have multiple alleles and many possible genotypes. - an individual could show an extra VNTR band merely by chance. - any band in the sample could have been degraded by nucleases.

the DNA in the sample must match its origin.

On which strand is DNA synthesis discontinuous, occurring in fragments that are later connected? the lagging strand Both strands synthesize DNA in fragments. the leading strand

the lagging strand

On which strand are new nucleotides being added in the same direction as the replication fork is opening? - the leading strand - the lagging strand - On both strands, DNA synthesis is proceeding in the same direction as the replication fork.

the leading strand

What is the first thing to occur in DNA replication? - the removal of the RNA primer, which is replaced by DNA - the extension of DNA from the 3′ end of the RNA primer - the strands of the DNA double helix are separated - the synthesis of a short RNA primer

the strands of the DNA double helix are separated

What is the function of the enzyme DNA polymerase? - to synthesize a strand of mRNA using mRNA as a template - to synthesize a polypeptide using DNA as a template - to synthesize a strand of DNA using DNA as a template - to synthesize a strand of DNA using a polypeptide as a template - to synthesize a strand of mRNA using DNA as a template

to synthesize a strand of DNA using DNA as a template

A skin cell in G2 of interphase has _____ as much DNA as it had in G1. half exactly twice four times one-fourth

twice S phase, where DNA synthesis occurs, and the chromosomes are all replicated, is in between G1 and G2 phases of the cell cycle.

How frequently is an improper base incorporated into the growing daughter strand? - about half the time - each time there is a purine rather than a pyrimidine on the template strand - frequently - very rarely

very rarely

When we say that DNA replication is semiconservative, we mean that: - parental DNA stays in the parent cell and daughter DNA ends up in the daughter cell. - when DNA is replicated each new double helix contains one parental strand and one newly synthesized daughter strand. - only half of an organism's DNA is replicated during each cell division. - None of the other answer options is correct.

when DNA is replicated each new double helix contains one parental strand and one newly synthesized daughter strand.