Biology 101 Chapter 11: DNA: The Genetic Material

Select all of the following that are true of the base pairs of a DNA molecule.

- G pairs with C.- A pairs with T.- Base pairs project toward the middle of a DNA strand.

Select all of the following that are large organic bases known as purines in DNA.

- adenine - guanine

Select all of the following that are characteristics of a DNA molecule.

- contains base pairs- has a sugar-phosphate backbone- double-stranded helix- contains deoxyribose sugars

Put the following steps of DNA replication into the correct order, beginning with the first step at the top.

-Helicase unwinds the DNA double helix. -The new strand is begun by a primer -The DNA polymerase adds the correct complementary nucleotide. The primer are removed, and segments of newly synthesize DNA are joined.

Select all of the ways that CRISPR technology can be used.

-alter complementary base-pairing rules -modify which amino acid is encoded by each codon on the mRNA move genes from one part of a genome to another

What enzyme functions in unwinding the DNA double helix during DNA replication?

helicase

tautomeric shift

hydrogen atoms move to form a base with altered hydrogen bonding properties.

DNA is a long chain of subunits called ______.

nucleotides

What subunits make up DNA?

nucleotides

Select all the components of a DNA nucleotide.

organic base phosphate group deoxyribose sugar

What is a characteristic of double-stranded DNA?

2 nanometers in width 10 base pairs per turn 0.34 nanometers per base pair 2 nanometers in width and 10 base pairs per turn R// All of the answer choices are correct.

The DNA molecule is a double , a structure that resembles a winding staircase of two strands.

Helix

If one strand in a DNA molecule has the sequence of bases TTACGCTA, what is the sequence of the other strand?

AATGCGAT

The addition of what key component to an endonuclease gene drive could cause a gene preventing transmission of malaria to not only be inserted into a mosquito and passed on to its offspring but also to be passed on to all future descendants of the offspring?

CRISPR

What enzyme adds the correct complementary nucleotide to the newly formed DNA strand during DNA replication?

DNA polymerase

What enzyme is indicated by the black arrow on this image of a DNA replication fork?

DNA polymerase

What enzyme is responsible for assembling a new strand of complementary nucleotides on each old strand during DNA replication?

DNA polymerase

After DNA polymerase synthesizes new segments of DNA and the RNA primers are removed, an enzyme called RNA polymerase joins together the newly synthesized segments of DNA on the lagging strand.

False Reason: The enzyme that joins segments together on the lagging strand is called ligase. Refer to section 11.2.

What DNA molecule would be the most stable?

GCGTGCAC CGCACGTG

If the sequence of one strand of a DNA molecule is CGAT, the sequence of the complementary strand is

GCTA

The short DNA segments formed on the discontinuously replicated strand are called

Okazaki fragments.

Select all of the following that are the same in every nucleotide of DNA.

Phosphate Sugar

Select all the observations of Chargaff's rule.

The amount of A equals the amount of T. The amount of G equals the amount of C.

A mutation that changes a single nucleotide can result in a different amino acid being added into a protein.

True

Asymmetrical spacing of the backbones of the DNA double helix generates major and minor grooves.

True

DNA mutations are passed on to daughter cells produced by mitosis.

True

DNA replication results in two identical daughter molecules each consisting of one old (original) strand and one newly synthesized strand.

True

Double-stranded DNA consists of two antiparallel strands, meaning that one strand is oriented in the 5´ to 3´ direction, while the other is oriented in the 3´ to 5´ direction.

True

The point where separation of the DNA occurs is called the replication fork.

True

After a tautomeric shift in adenine

adenine bonds with cytosine

In Watson and Crick's model of DNA, the DNA molecule keeps a constant thickness because ______.

base pairs always consists of a purine and a pyrimidine

A pairs with T and not C because ______.

both A and T form two hydrogen bonds

A mutation that causes a change in a single nucleotide in DNA

changes the corresponding nucleotide in mRNA, resulting in a different codon.

If the sequence of one strand of a DNA molecule is GCGTAA, then the sequence of the other strand is CGCATT due to ______.

complementarity

Select all of the following that are small, single-ringed, organic bases known as pyrimidines in DNA.

cytosine thymine

What order represents how the components of a DNA nucleotide are connected?

phosphate-sugar-base

Chargaff suggested that DNA had equal amounts of purines and pyrimidines, which Watson and Crick confirmed when they stated that a bulky ______ on one strand pairs with a slender ______ on the other strand of DNA.

purine; pyrimidine

Adenine and guanine are the large, double-ringed, organic bases called ______ in the nucleotides of DNA.

purines

Cytosine and thymine are the small, single-ringed, organic bases called ______ found in DNA nucleotides.

pyrimidines

The copying of DNA before cell division is called DNA ______. Multiple choice question.

replication

In the DNA double helix, the ______ form the backbone strands, and the ______ face each other in the middle.

sugars and phosphate groups; bases

The complementarity of DNA refers to the fact that ______.

the base sequence on one strand of DNA completely determines the base sequence on the other strand

DNA replication

the copying of DNA before cell division.

Chargaff's rule says that in a molecule of DNA, ______.

there are equal amounts of purines and pyrimidines

How many hydrogen bonds exist between cytosine and guanine?

three

What is the function of the enzyme primase during DNA replication?

to add an RNA primer to enable replication of DNA

How many hydrogen bonds occur between adenine and thymine?

two