Chromatin and Chromosomes

This is an MCQ-based quiz for GRE on the topic of Chromatin and Chromosomes.

Chromatin is a complex formed by histones packaging the DNA double helix. Chromosomes are structures of proteins and nucleic acids found in the living cells and carry genetic material. Chromatin is composed of nucleosomes. Chromosomes are composed of condensed chromatin fibers.

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Which answer choice incorrectly matches the type of chromatin with the phase of mitosis?

Euchromatin—interphase Euchromatin—telophase Heterochromatin—interphase Heterochromatin—metaphase Heterochromatin—prophase

What is a nucleosome?

A repeating unit of chromatin A membrane-bound organelle that contains epigenetic information A complex of proteins that controls nuclear import Non-chromosomal DNA that is free floating in the cytosol

__________ are proteins used to package DNA.

Nucleosomes Chromatins Histones Telomerases

__________ is also known as "light" chromatin and represents DNA that can actively undergo __________.

Heterochromatin . . . translation Heterochromatin . . . transcription Euchromatin . . . translation Euchromatin . . . transcription

Which of the following is true of chromatin?

Nucleosomes consist of DNA wrapped in proteins known as transcriptions factors Patterns of methylation or acetylation of histones can regulate gene expression Chromatin never gets further compacted than the 10nm fiber Chromatin is present in all eukaryotic and prokaryotic DNA

Which correctly describes eukaryotic histones in a nucleosome structure?

A core histone octamer plus 2 linker histones A core histone heptamer plus a linker histone A core histone octamer plus a linker histone A core histone plus a linker histone octamer A core histone nonamer

Which of the following are not observed when performing a karyotype?

Size of chromosomes Position of centromeres Differences in satellite chromosome position and number Gene loci Number of chromosomes

What is the name of the globular protein around which DNA is wrapped in a chromosome?

Nucleosome Histone Chromatin Nucleolus

Which of the following proteins is necessary for nucleosome formation?

DNA ligase Histones Histone methyltransferases Nuclear lamin Chromatin

Proteins that DNA wraps around to form tightly packaged and organized structural units are referred to as __________.

Histones

Chromosomes

Nucleosomes

None of the other answers

Chromatin