Question 1

Which experiment provided the most direct evidence that DNA, and not protein, is the hereditary material in cells?

Accepted Answer

Avery, MacLeod, and McCarty's experiment using DNase, RNase, and protease

Question 2

According to Chargaff’s rule, if a DNA sample contains 30% adenine, what percentage of guanine does it contain?

Accepted Answer

20%

Question 3

Which of the following best describes the structure of DNA as determined by Watson and Crick?

Accepted Answer

A double helix with antiparallel strands and complementary base pairing

Question 4

What is the significance of the major and minor grooves in the DNA double helix?

Accepted Answer

They provide binding sites for DNA-binding proteins to interact with specific base sequences

Question 5

Which of the following statements about DNA replication is correct?

Accepted Answer

Replication is semiconservative, with each daughter molecule containing one parental and one new strand

Question 6

In the Meselson-Stahl experiment, what was the key evidence supporting semiconservative replication?

Accepted Answer

The formation of hybrid DNA (intermediate density) after one round of replication in $$^{14}N$$ medium

Question 7

If the sequence of a DNA template strand is 5'-ATCGGTA-3', what is the sequence and polarity of the newly synthesized complementary strand?

Accepted Answer

3'-TAGCCAT-5'

Question 8

Why is replication of the ends of linear chromosomes (telomeres) problematic in eukaryotes?

Accepted Answer

DNA polymerase cannot fully replicate the 3' ends, leading to progressive shortening

Question 9

How does telomerase solve the end-replication problem in eukaryotic chromosomes?

Accepted Answer

By using an RNA template to extend the 3' end of the DNA strand

Question 10

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

Accepted Answer

DNA polymerase III

Question 11

A researcher is studying a eukaryotic chromosome that is 100,000 base pairs long. If each nucleosome contains 147 base pairs of DNA, approximately how many nucleosomes are required to package this chromosome?

Accepted Answer

$$\approx 680$$

Question 12

Which enzyme is responsible for joining Okazaki fragments during DNA replication?

Accepted Answer

DNA ligase

Question 13

In a bacterial chromosome, DNA replication begins at a single origin (oriC) and proceeds bidirectionally. What is the result of this process?

Accepted Answer

Two replication forks move in opposite directions, meeting at the terminus

Question 14

Which of the following best explains why eukaryotic genomes require multiple origins of replication?

Accepted Answer

Eukaryotic chromosomes are much larger and linear, so multiple origins ensure timely replication

Question 15

Which bond type is responsible for holding the two DNA strands together in the double helix?

Accepted Answer

Hydrogen bonds

Question 16

A scientist uses dideoxynucleotide sequencing to determine a DNA sequence. What is the main advantage of next-generation sequencing technologies over traditional Sanger sequencing?

Accepted Answer

Next-generation sequencing allows massively parallel sequencing, increasing speed and throughput

Question 17

Which of the following scenarios best illustrates the application of the central dogma in a medical context?

Accepted Answer

A mutation in DNA leads to a change in mRNA, resulting in a defective protein that causes cystic fibrosis

Question 18

Which of the following is a correct representation of complementary base pairing in DNA?

Accepted Answer

$$A = T$$ and $$G = C$$

Question 19

During DNA replication, which strand is synthesized continuously and in the same direction as the replication fork?

Accepted Answer

Leading strand

DNA Structure, Replication, and Chromatin Organization: Study Notes for Genetics Students

Guida di studio - Domande di pratica

Study guide - Flashcard