Question 1

Why is the AMY1 gene more prevalent in humans than in chimpanzees and more prevalent in some human populations than others? (Select all correct choices)

Accepted Answer

Chimpanzees consume less starch, so they need less amylase, while some human populations consume more starch, leading to a higher prevalence of the AMY1 gene.

Question 2

The bonds that hold DNA and RNA backbones together are known as __________.

Accepted Answer

The bonds that hold DNA and RNA backbones together are known as 3'-5'-phosphodiester linkages. These linkages involve the connecting of the 3' carbon of one nucleotide to the 5' carbon of another nucleotide through a phosphate group. Choice A is incorrect because it incorrectly lists the positions of the carbons involved. Choice C is incorrect because it refers to a different type of chemical bond. Choice D is incorrect because it refers to the bond between the sugar and nitrogenous base of a nucleotide, not the bond between nucleotides in the backbone. Choice E is incorrect because it refers to a bond found in proteins, not nucleic acids.

Question 3

Purines are characterized by _______; pyrimidines are characterized by ______.

Accepted Answer

Purines are characterized by two rings, while pyrimidines are characterized by one ring.

Question 4

Which statement below explains the uniform width of the DNA molecule along its entire width?

Accepted Answer

The uniform width of the DNA molecule is maintained because a pyrimidine nitrogenous base (which has a single ring structure) always pairs with a purine nitrogenous base (which has a double ring structure). This pairing (Cytosine with Guanine, and Adenine with Thymine in DNA) ensures a consistent width along the length of the DNA molecule.

Question 5

Which of the following is a DNA nucleotide?

Accepted Answer

A DNA nucleotide consists of a phosphate group, a nitrogenous base (in this case, guanine), and a deoxyribose sugar. Therefore, only option B fits this description.

Question 6

How is the degree of DNA denaturation measured in C₀t studies?

Accepted Answer

The absorbance of UV light by DNA increases as DNA denatures, therefore measuring the absorbance of UV light is a common method for determining the degree of denaturation in C₀t studies.

Question 7

The ends of a polynucleotide chain are the ____ end and the ____ end.

Accepted Answer

The 3' end of a polynucleotide chain has a free hydroxyl (-OH) group on the 3' carbon of the sugar molecule, while the 5' end has a free phosphate group on the 5' carbon of the sugar molecule. Therefore, the correct answer is C.

Question 8

The original model of DNA structure stated that each unit in DNA contained all four nitrogenous bases in a repeating pattern; it was called the ________.

Accepted Answer

The original model of DNA structure was proposed by Phoebus Levene and it stated that DNA was composed of repeating units, each containing all four nitrogenous bases (adenine, thymine, cytosine, and guanine) in a fixed proportion. This theory was known as the Tetranucleotide Theory. However, this model was later disproved by Rosalind Franklin's X-ray crystallography data and Watson and Crick's discovery of the double helix structure of DNA.

Question 9

Which of the following is an RNA nucleoside?

Accepted Answer

Cytosine is a nitrogenous base found in RNA, and it is always paired with ribose, which is a sugar molecule specific to RNA nucleotides. Therefore, option C (cytosine and ribose) is the correct answer. The other options either have deoxyribose instead of ribose or contain a nitrogenous base that is found in DNA (adenine, guanine, and thymine).

Question 10

What function does topoisomerase II serve in preparation for mitosis?

Accepted Answer

Topoisomerase II is responsible for disentangling DNA molecules by cutting and rejoining strands of DNA, thus preventing tangling and allowing for proper chromosome separation during mitosis.

Question 11

The backbone of a DNA molecule is _________.

Accepted Answer

The backbone of a DNA molecule is made up of alternating phosphate and sugar groups, specifically deoxyribose sugar. The nitrogenous bases (adenine, guanine, cytosine, and thymine) are attached to the deoxyribose sugars.

Question 12

Which type of enzyme is essential for processes like DNA replication and transcription to prevent excessive supercoiling from developing as the complementary strands of the DNA duplex separate and unwind?

Accepted Answer

Topoisomerases are enzymes that are essential for DNA replication and transcription because they prevent excessive supercoiling from developing as the complementary strands of the DNA duplex separate and unwind. Topoisomerases work by breaking the DNA strands, allowing them to rotate around each other, and then rejoining them to alleviate the tension caused by DNA unwinding.

Question 13

The inheritable information encoded in DNA resides in ________.

Accepted Answer

The DNA base sequence contains the genetic information that is inherited and passed down from one generation to the next. The phosphates and sugars in the DNA backbone provide the structure for the DNA molecule but do not contain the actual genetic information.

Question 14

________ refers to the fact that the sequence of one DNA strand specifies the sequence of the other strand in the double helix.

Accepted Answer

Complementarity refers to the fact that the sequence of one DNA strand is complementary to and thus specifies the sequence of the other strand in the double helix. This is due to the pairing of complementary nitrogenous bases (A with T, and C with G) between the two strands. Indirectionality, Complexity, Similarity, and Compulsivity do not accurately describe this property of DNA.

Question 15

What technique supplied the data that led Watson and Crick to hypothesize the double helical structure of DNA?

Accepted Answer

X-ray crystallography was used by Rosalind Franklin and Maurice Wilkins to generate X-ray diffraction images of DNA fibers, which provided crucial information about the molecular structure of DNA. Watson and Crick used these images, along with other data, to propose the double helical structure of DNA.

Question 16

In humans, the genome is essentially equivalent to all of the genetic information that is present in a ______ set of chromosomes.

Accepted Answer

The human genome is defined as the complete set of genetic information in a haploid set of chromosomes, which includes one copy of each chromosome.

Question 17

In a right-handed double helix, if one looks down the central axis of the molecule, _________.

Accepted Answer

In a right-handed double helix, each strand follows a clockwise path as it moves away from the observer when one looks down the central axis of the molecule.

Question 18

Which type of enzyme makes a transient break in both DNA duplex strands and then transports another segment of a DNA molecule (or separate molecule entirely)through the break and reseals the severed strands?

Accepted Answer

Type II topoisomerases make a transient break in both DNA duplex strands, pass another segment of a DNA molecule through the break, and then reseal the severed strands. Type I topoisomerases also make transient breaks but only in one strand of the DNA duplex. Topologicases and isomerases are not types of topoisomerases.

Question 19

You isolate DNA from a particular organism and analyze it. The amount of adenine was 6 µmoles and the A+T/G+C ratio is 4.0. How much guanine should be in the sample?

Accepted Answer

Given the A+T/G+C ratio is 4.0 and the amount of adenine (A) is 6 µmoles, the total amount of adenine and thymine (A+T) is 4 times the amount of guanine and cytosine (G+C). Since A = T in DNA, A+T = 12 µmoles. Therefore, G+C must be 3 µmoles (since 12 µmoles is 4 times 3 µmoles). Given that G = C in DNA, the amount of guanine (G) must be half of 3 µmoles, which is 1.5 µmoles.

Question 20

Which molecule provides a DNA molecule with most of its negative charge?

Accepted Answer

The phosphate groups in the DNA molecule contain negatively charged oxygens, which provide the molecule with its overall negative charge.

Quiz 10: The Nature of the Gene and the Genome

Why is the AMY1 gene more prevalent in humans than in chimpanzees and more prevalent in some human populations than others? (Select all correct choices)

The bonds that hold DNA and RNA backbones together are known as __________.

Purines are characterized by _; pyrimidines are characterized by .

Which statement below explains the uniform width of the DNA molecule along its entire width?

Which of the following is a DNA nucleotide?

How is the degree of DNA denaturation measured in C₀t studies?

The ends of a polynucleotide chain are the end and the end.

The original model of DNA structure stated that each unit in DNA contained all four nitrogenous bases in a repeating pattern; it was called the ________.

Which of the following is an RNA nucleoside?

What function does topoisomerase II serve in preparation for mitosis?

The backbone of a DNA molecule is _________.

Which type of enzyme is essential for processes like DNA replication and transcription to prevent excessive supercoiling from developing as the complementary strands of the DNA duplex separate and unwind?

The inheritable information encoded in DNA resides in ________.

________ refers to the fact that the sequence of one DNA strand specifies the sequence of the other strand in the double helix.

What technique supplied the data that led Watson and Crick to hypothesize the double helical structure of DNA?

In humans, the genome is essentially equivalent to all of the genetic information that is present in a ______ set of chromosomes.

In a right-handed double helix, if one looks down the central axis of the molecule, _________.

Which type of enzyme makes a transient break in both DNA duplex strands and then transports another segment of a DNA molecule (or separate molecule entirely) through the break and reseals the severed strands?

You isolate DNA from a particular organism and analyze it. The amount of adenine was 6 µmoles and the A+T/G+C ratio is 4.0. How much guanine should be in the sample?

Which molecule provides a DNA molecule with most of its negative charge?

Quiz 10: The Nature of the Gene and the Genome

Why is the AMY1 gene more prevalent in humans than in chimpanzees and more prevalent in some human populations than others? (Select all correct choices)

The bonds that hold DNA and RNA backbones together are known as __________.

Purines are characterized by _______; pyrimidines are characterized by ______.

Which statement below explains the uniform width of the DNA molecule along its entire width?

Which of the following is a DNA nucleotide?

How is the degree of DNA denaturation measured in C0t studies?

The ends of a polynucleotide chain are the ____ end and the ____ end.

The original model of DNA structure stated that each unit in DNA contained all four nitrogenous bases in a repeating pattern; it was called the ________.

Which of the following is an RNA nucleoside?

What function does topoisomerase II serve in preparation for mitosis?

The backbone of a DNA molecule is _________.

Which type of enzyme is essential for processes like DNA replication and transcription to prevent excessive supercoiling from developing as the complementary strands of the DNA duplex separate and unwind?

The inheritable information encoded in DNA resides in ________.

________ refers to the fact that the sequence of one DNA strand specifies the sequence of the other strand in the double helix.

What technique supplied the data that led Watson and Crick to hypothesize the double helical structure of DNA?

In humans, the genome is essentially equivalent to all of the genetic information that is present in a ______ set of chromosomes.

In a right-handed double helix, if one looks down the central axis of the molecule, _________.

Which type of enzyme makes a transient break in both DNA duplex strands and then transports another segment of a DNA molecule (or separate molecule entirely) through the break and reseals the severed strands?

You isolate DNA from a particular organism and analyze it. The amount of adenine was 6 µmoles and the A+T/G+C ratio is 4.0. How much guanine should be in the sample?

Which molecule provides a DNA molecule with most of its negative charge?

Purines are characterized by _; pyrimidines are characterized by .

How is the degree of DNA denaturation measured in C₀t studies?

The ends of a polynucleotide chain are the end and the end.