Question 1

Which of the following best describes the difference between DNA and RNA nucleotides?

Accepted Answer

DNA nucleotides have a pentose sugar with an H on the 2' carbon, while RNA nucleotides have an OH group on the 2' carbon.

Question 2

According to Chargaff's rules, if a segment of DNA contains 60 adenines and 50 cytosines, how many nucleotides are present in the segment?

Accepted Answer

$$60 + 60 + 50 + 50 = 220$$

Question 3

Which of the following statements about homologous chromosomes is correct?

Accepted Answer

Homologous chromosomes contain the same genes but may have different alleles.

Question 4

What is the primary function of nucleic acids in cells?

Accepted Answer

They store and transmit genetic information.

Question 5

In the Hershey-Chase experiment, which radioactive element was used to label DNA?

Accepted Answer

Phosphorus-32 ($$^{32}P)$$

Question 6

Which molecule was identified as the 'transforming principle' in Griffith's experiment by Avery, MacLeod, and McCarty?

Accepted Answer

Nucleic acid (DNA)

Question 7

Which of the following best explains why prokaryotic chromosomes are supercoiled?

Accepted Answer

To condense the genome for efficient storage in the cell.

Question 8

A diploid human cell contains 46 chromosomes. How many chromosomes are present in a human gamete?

Accepted Answer

23

Question 9

Which of the following is the correct order of DNA compaction in eukaryotic cells?

Accepted Answer

Double helix → Nucleosome → Chromatin → Higher order chromatin → Condensed chromosome

Question 10

Which nitrogenous base is found in RNA but not in DNA?

Accepted Answer

Uracil

Question 11

If a DNA molecule has 30% adenine, what percentage of guanine does it contain?

Accepted Answer

$$20\%$$

Question 12

Which of the following best describes the outcome when R strain bacteria are mixed with heat-killed S strain and injected into mice?

Accepted Answer

The mice die because the R strain is transformed into a virulent form.

Question 13

Which enzyme, when destroyed in Avery, MacLeod, and McCarty's experiment, prevented transformation of R strain to S strain?

Accepted Answer

Nuclease

Question 14

What is the structural difference between purines and pyrimidines?

Accepted Answer

Purines have a double ring structure, while pyrimidines have a single ring structure.

Question 15

Which of the following is NOT a component of a nucleotide?

Accepted Answer

Fatty acid

Question 16

Which statement best describes the role of chromosomes in eukaryotic cells?

Accepted Answer

Chromosomes carry genetic information in the form of DNA.

Question 17

In the process of bacteriophage infection, what is injected into the host bacterial cell?

Accepted Answer

Viral DNA

Question 18

Which of the following best explains why the S strain of bacteria is virulent in Griffith's experiment?

Accepted Answer

It has a polysaccharide capsule that protects it from the immune system.

Question 19

Which of the following is true about the number of chromosomes in human somatic cells and gametes?

Accepted Answer

Somatic cells have 46 chromosomes, gametes have 23.

Question 20

Which of the following best describes the structure of a nucleosome?

Accepted Answer

A nucleosome consists of DNA wrapped around 8 histone proteins.

Genetic Material, DNA Structure, Chromosomes, and Experiments Demonstrating DNA as Genetic Material

Study Guide - Practice Questions