Chapter 14 | GEN BIO 111

X-ray diffraction was used to determine that the diameter of a DNA molecule is ________.

2 nm

A segment of DNA has the sequence 5'-ATGCCC-3'. The complementary sequence would be...

5'-GGGCAT-3'

How are the origins of replication adjusted in eukaryotic cells, so that early in the embryonic development of eukaryotic organisms DNA can be replicated faster?

Cells can increase the number of origins used in early development.

Which of these is not involved in the unwinding of DNA during replication?

RNA polymerase (makes primers)

The major significance of the Hershey and Chase's experiments is that they...

determine that DNA is the genetic material.

An Okazaki fragment is a short fragment of DNA created on the ________ strand of DNA.

lagging

The continuously synthesized DNA strand is called the ________ strand, while the discontinuously synthesized strand is called the ________ strand.

leading; lagging

In an aging cell, the activity of telomerase would be...

low

Radiation, UV light, x-rays, and chemicals in the environment can cause mutations in DNA and are therefore referred to as ________.

mutagen

Nucleotides contain a sugar, a phosphate, and a ________ base.

nitrogenous

Which origins are more sequence-specific?

oriC

Repeating sugar and phosphate units in a single DNA strand make up the...

phosphodiester backbone.

The enzyme DNA ________ covalently links nucleotides to synthesize new DNA strands together during DNA replication.

polymerase

The enzyme DNA ________ synthesizes the RNA primers required by DNA polymerases during replication.

primase

The ________ is the part of the replisome composed of primase, helicase, and accessory proteins that prime the lagging strand.

primosome

The function of telomeres is to...

protect the ends of chromosomes

A ________ ________ is the partial opening of a DNA helix to form two single strands.

replication fork

The DNA controlled by an origin is called a ________.

replicon

DNA replication that leads to the production of double helices with one parental strand and one newly synthesized strand is consistent with...

semiconservative replication

Which of the following is a region at the ends of eukaryotic chromosomes?

telomere

The partial opening of a DNA helix to form two single strands is called

the replication fork

Chargaff's experiments showed that the amount of adenine in a sample was always the same as the amount of ________.

thymine

In base pairing between complimentary strands of DNA, A pairs with ________ and C pairs with ________.

thymine; guamine

Chargaff's rule indicates that the amount of A in a sample is equal to the amount of ________ and the amount of C in a sample is equal to the amount of ________.

thymine; guanine

The enzyme DNA ________ relieves coiling in DNA strands ahead of the replication fork.

topoisomerase or gyrase

Griffith defined ________ as the transfer of virulence from one cell to another.

transformation

How many hydrogen bonds are formed between adenine and thymine in the double DNA helix?

two

Short fragments of DNA created on the lagging strand of DNA during replication are called...

Okazaki fragments

The DNA fibers Franklin used in her x-ray diffraction studies came from...

Wilkins

When trying to discover the substance responsible for transformation, Avery, MacLeod and McCarty removed ________ from their preparation and found that the transforming activity persisted.

protein

DNA repair mechanisms have evolved because...

there is no way for cells to avoid exposure to mutagens

In a DNA double helix, two hydrogen bonds form between...

adenine and thymine

DNA'S phosphodiester ________ is composed of sugars and phosphates.

backbone or spine

The enzymes in the replisome are active on...

both strands

Telomeres are related to...

cellular aging

Genes, which contain trait specifying information, are located on...

chromosomes

Which model for DNA replication suggests that both strands of the double helix remain intact and the new DNA double helix consists of two new DNA strands?

conservative

The enzyme ________ uses ATP to unwind the DNA template.

helicase

The primary purpose of the Meselson and Stahl experiments was to determine...

how DNA replicates

Which of these are part of the Watson-Crick model?

1. Each DNA molecule is composed of two strands that run antiparallel. 2. Each DNA molecule is composed of 2 phosphodiester strands.

Which of these are involved in the unwinding of DNA?

1. Helicase 2. Single-strand binding proteins 3. Topoisomerase

Which enzymes did Avery, MacLeod, and McCarty use in order to identify the genetic material?

1. RNA digesting enzymes 2. protein-digesting enzymes 3. DNA digesting enzymes

Of the following list, which 3 items are required for DNA replication?

1. Template 2. Polymerase 3. Nucleotides

Features of the Watson and Crick model include ________.

1. a helical structure 2. a double stranded structure 3. a sugar phosphate backbone

The DNA structure proposed by Watson and Crick involves...

1. a sugar phosphate backbone 2. a helical structure 3. two grooves (major and minor)

The two main eukaryotic DNA polymerases that extend DNA are...

1. delta 2. epsilon

DNA primase (choose all that apply)...

1. makes a primer about 10 -20 nucleotides in length. 2. makes a primer of RNA complementary to the DNA.

Select all of the following that are components of a nucleotide.

1. sugar 2. phosphate group 3. nitrogenous base

During the synthesis of the lagging DNA strand, Okazaki fragments are joined by the enzyme...

DNA ligase.

Even with the proofreading abilities of ________, mutations still occur.

DNA polymerase

Mutations occur despite the proofreading efforts of ________, therefore, repair mechanisms are necessary to prevent the accumulation of errors.

DNA polymerase

Which enzyme covalently links nucleotides together during DNA replication?

DNA polymerase

In eukaryotes, priming is accomplished by a complex of primase and...

DNA polymerase a

Which of the following facilitates the reversal of damage to our hereditary material before a permanent mutation can occur?

DNA repair systems

Which types of cells have more than one origin of replication?

Eukaryotes

The experiments with radioactively labeled phage that showed that DNA was the genetic material were performed by...

Hershey and Chase

On which strand does the removal of the last primer leave a gap that cannot be primed at the ends of the chromosome.

Lagging

Which of these is not required for DNA replication?

Lipids

While one strand is synthesized continuously, replication is ________ on the other strand, because polymerases can only synthesize DNA in one direction and the two DNA strands run in opposite directions.

discontinuous or lagging

This model of DNA replication suggests that newly synthesized strands of DNA would consist of mixtures of parental and newly synthesized strands of DNA.

dispersive

Franklin used a technique called x-ray ________ to suggest that DNA has a helical structure.

dittraction

In which of the following chromosomal entities are an individual's traits specified?

genes

The enzyme DNA ________ is the topoisomerase involved in DNA replication.

gyrase

Agents that cause mutation are known as...

mutagens

The description of transformation as the transfer of virulence from one cell to another was proposed by...

Griffith

Franklin determined that the structure of DNA was helical based on ________.

x-ray diffraction analysis

The DNA backbone is composed of (choose all that apply)...

1. sugars. 2. phosphate groups.

Match the following strands with the type of synthesis: 1. leading strand... 2. lagging strand...

1. synthesized continuously 2. synthesized in small fragments that are later connected

The problems in replicating the ends of linear chromosomes are caused by (choose all that apply) ________.

1. the need for a primer 2. the directionality of polymerases

The experiments used to distinguish between the three potential DNA replication mechanisms were performed by...

Meselson and Stahl.

Why do eukaryotic cells have multiple origins of replication?

To ensure timely replication of multiple, relatively large chromosomes

Bacterial replication (for example in E. coli) begins at...

a single origin

During DNA replication, the ________ strand is synthesized continuously while the ________ strand is synthesized as small fragments that are connected to each other to form a continuous strand.

leading; lagging

DNA ________ is an enzyme that joins to adjacent Okazaki fragments during the synthesis of the lagging DNA strand.

ligase

The ________ is a macromolecular assembly of enzymes involved in DNA replication.

replisome

The stability of DNA molecules is due to...

the sum of the hydrogen bonds between base pairs

What class of enzymes relieve torsional strain in DNA strands ahead of the replication fork?

Topoisomerases