Question 1

Which of the following best describes the structure of DNA as discovered by Watson and Crick using Rosalind Franklin's X-ray diffraction data?

Accepted Answer

A double helix with antiparallel strands and complementary base pairing

Question 2

Which of the following statements about nucleotides is correct?

Accepted Answer

Nucleotides are composed of a phosphate group, a pentose sugar, and a nitrogenous base

Question 3

Which of the following base pairs is held together by three hydrogen bonds in DNA?

Accepted Answer

Guanine and Cytosine

Question 4

According to Chargaff’s Rule, if a DNA molecule contains 30% adenine, what percentage of guanine would you expect to find?

Accepted Answer

$$20\%$$

Question 5

Which of the following is a difference between DNA and RNA?

Accepted Answer

DNA is double-stranded, while RNA is single-stranded

Question 6

Which of the following best explains why chromatin is the preferred form of DNA when the cell is not dividing?

Accepted Answer

Chromatin is more relaxed, allowing access for replication and repair enzymes

Question 7

Which of the following is a purine base found in both DNA and RNA?

Accepted Answer

Adenine

Question 8

What is the function of telomeres in eukaryotic chromosomes?

Accepted Answer

They protect genetic information at the ends of chromosomes

Question 9

A scientist discovers a nucleic acid molecule with the following characteristics: single-stranded, contains uracil, and has a ribose sugar. What is this molecule?

Accepted Answer

RNA

Question 10

Which of the following best describes the role of hydrogen bonds in the structure of DNA?

Accepted Answer

They hold the two complementary strands together by joining nitrogenous bases

Question 11

If a segment of DNA has the sequence 5'-ATCG-3', what is the complementary sequence on the other strand?

Accepted Answer

3'-TAGC-5'

Question 12

Which of the following statements about chromosomes is correct?

Accepted Answer

Chromosomes are condensed forms of DNA that appear during cell division

Question 13

Which of the following best explains why the number of chromosomes does not determine the complexity of an organism?

Accepted Answer

Chromosome number is unrelated to the amount of genetic information or gene regulation

Question 14

During DNA replication, which type of bond is formed between the phosphate group of one nucleotide and the sugar of the next?

Accepted Answer

Phosphodiester bond

Question 15

A mutation causes a cytosine (C) in DNA to be replaced by a thymine (T). Which of the following base pairing changes would result from this mutation?

Accepted Answer

The base would now pair with adenine (A) instead of guanine (G)

Question 16

Which experiment provided the first strong evidence that DNA, and not protein, is the genetic material?

Accepted Answer

Hershey and Chase’s experiment with bacteriophages

Question 17

Which of the following best describes the antiparallel nature of DNA?

Accepted Answer

The two strands run in opposite directions: one 5' to 3', the other 3' to 5'

Question 18

Which of the following is a correct pairing of a purine and a pyrimidine in DNA?

Accepted Answer

Adenine and Thymine

Question 19

A gene is best defined as:

Accepted Answer

A section of DNA that codes for a protein

Question 20

Which of the following best explains why uracil is found in RNA but not in DNA?

Accepted Answer

Uracil is less stable than thymine and is more suitable for the temporary nature of RNA

Cellular Reproduction and DNA Structure: Study Notes for General Biology

Guida di studio - Domande di pratica

Study guide - Flashcard