$$2^n \times$$ original DNA content

Question 1

Which of the following statements best describes the structure of bacterial chromosomes?

Accepted Answer

Bacterial chromosomes are double-stranded, circular DNA molecules associated with histone-like proteins.

Question 2

Polytene chromosomes are characterized by which of the following features?

Accepted Answer

They consist of clusters of identical homologous chromosomes with 1000-5000 DNA strands in precise alignment.

Question 3

Which region of polytene chromosomes is associated with active transcription?

Accepted Answer

Puff regions

Question 4

Lampbrush chromosomes are most commonly observed in which cell type and stage?

Accepted Answer

Vertebrate oocytes during prophase I of meiosis

Question 5

Which of the following statements about chromatin structure in eukaryotes is correct?

Accepted Answer

Chromatin consists of DNA associated with histone and non-histone proteins, forming nucleosomes as the basic unit.

Question 6

What is the approximate number of base pairs contained in the core particle of a nucleosome?

Accepted Answer

$$147$$

Question 7

Which histone protein binds to the linker DNA between nucleosomes, facilitating higher-order chromatin structure?

Accepted Answer

H1

Question 8

Chromatin remodeling is essential for which cellular processes?

Accepted Answer

DNA replication and gene expression

Question 9

Which chemical modifications of histone tails are important for regulation of gene expression?

Accepted Answer

Acetylation, methylation, and phosphorylation

Question 10

Epigenetics refers to heritable yet reversible changes in gene expression that are NOT due to:

Accepted Answer

Changes in DNA sequence

Question 11

Which type of chromatin is mostly inactive for gene expression and appears darker during interphase?

Accepted Answer

Heterochromatin

Question 12

G-banding of chromosomes reveals which regions?

Accepted Answer

A-T rich regions

Question 13

Satellite DNA is highly repetitive and is most commonly found in which chromosomal region?

Accepted Answer

Centromeric heterochromatic regions

Question 14

Which of the following is NOT a feature of mitochondrial DNA?

Accepted Answer

DNA associates with histone proteins

Question 15

Which equation best represents the total DNA content in a polytene chromosome after $$n$$ rounds of replication without cell division?

Accepted Answer

$$2^n 	imes$$ original DNA content

Question 16

Which category of repetitive DNA includes SINEs and LINEs, and what proportion of the human genome do they represent?

Accepted Answer

Moderately repetitive DNA; about 45% of the human genome

Question 17

A scientist uses Giemsa staining after proteolytic digestion to visualize chromosomes. Which banding pattern is she most likely observing?

Accepted Answer

G-banding

Question 18

Which of the following best describes the nucleosome 'beads-on-a-string' structure observed under electron microscopy?

Accepted Answer

DNA wound around octet histone cores, separated by linker DNA

Question 19

Which of the following is a real-world application of short tandem repeats (STRs) in genetics?

Accepted Answer

Forensic DNA fingerprinting

Question 20

If a eukaryotic cell needs to express a gene, which chromatin state must the DNA be in?

Accepted Answer

Euchromatin

Chromosome Structure and DNA Sequence Organization: Study Guide

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