Heterochromatin and Euchromatin Overview

<p>DNA translation (B)</p> Signup and view all the answers

<p>It is permanently silenced DNA. (C)</p> Signup and view all the answers

<p>To repress transcription of genes that are not necessary for the current cellular function. (B)</p> Signup and view all the answers

<p>The centromere region (B)</p> Signup and view all the answers

<p>Heterochromatin is more compact and requires more time to unwind for replication. (C)</p> Signup and view all the answers

<p>To ensure equal gene expression between males and females. (D)</p> Signup and view all the answers

<p>One of the two X chromosomes in females is randomly inactivated in every cell, leading to mosaic expression of genes on the X chromosome. (D)</p> Signup and view all the answers

<p>Constitutive heterochromatin is always transcriptionally inactive, while facultative heterochromatin can be active or inactive depending on the cell type. (D)</p> Signup and view all the answers

<p>The gene will become less active or silenced. (D)</p> Signup and view all the answers

<p>To prevent the spread of heterochromatin along the chromosome. (B)</p> Signup and view all the answers

<p>It balances the expression of X-linked genes between males and females, resulting in equivalent amounts of products. (D)</p> Signup and view all the answers

<p>The mechanism of inactivation of the X chromosome. (A)</p> Signup and view all the answers

<p>Heterochromatization inhibits the transcription of genes on the inactive X chromosome. (A)</p> Signup and view all the answers

<p>It allows for the expression of genes on the inactive X chromosome in gametes, ensuring equal contributions from both parents. (A)</p> Signup and view all the answers

<p>Female mammals exhibit a mosaic pattern of gene expression from their X chromosomes. (B)</p> Signup and view all the answers

<p>Somatic Barr bodies are always transcriptionally inactive, while early embryonic X chromosomes can be either active or inactive. (D)</p> Signup and view all the answers

<p>Heterochromatin acts as a physical barrier, preventing access of transcription factors to the genes on the inactive X chromosome. (D)</p> Signup and view all the answers

<p>Acetylation of histone tails generally leads to increased gene expression. (D)</p> Signup and view all the answers

<p>H1 acts as a scaffold protein, organizing multiple nucleosomes into higher-order structures. (A)</p> Signup and view all the answers

<p>Histone acetyltransferase (HAT) (B)</p> Signup and view all the answers

<p>The histone code comprises a combination of histone modifications, influencing chromatin compaction and gene expression. (D)</p> Signup and view all the answers

<p>Increased accessibility of DNA to regulatory proteins. (D)</p> Signup and view all the answers

<p>Glycosylation (C)</p> Signup and view all the answers

<p>A complex, dynamic code, where modification patterns and combinations influence chromatin structure and gene expression. (A)</p> Signup and view all the answers

<p>It inhibits gene expression by limiting the accessibility of the DNA to regulatory factors. (B)</p> Signup and view all the answers

<p>Euchromatin (D)</p> Signup and view all the answers

<p>Histone modifications act as a code that influences the accessibility of DNA to transcription factors, impacting gene expression. (A)</p> Signup and view all the answers

A type of chromatin that remains compacted during interphase and is transcriptionally inactive.

A type of chromatin that is less compacted and accessible for transcription during interphase.

The arrangement of DNA into chromatin, which changes throughout the cell cycle.

The process of copying DNA into RNA, necessary for gene expression.

Heterochromatin that can be temporarily compacted or decompacted based on the cell's needs.

A type of heterochromatin that is always compacted and functionally inactive in all cell types.

A biochemical process involving the addition of methyl groups to DNA, influencing gene activity.

The process by which genetic material is physically mixed during cell division.

Euchromatin is active in gene expression, while heterochromatin suppresses it.

Euchromatin replicates early in the cell cycle, while heterochromatin replicates later.

Structures at the ends of chromosomes consisting of repeated DNA sequences and few genes.

The phenomenon where normally active genes become silenced when adjacent to heterochromatin.

The extension of heterochromatin influence across nearby regions in a chromosome.

Specialized sequences in the genome that block the spread of heterochromatin.

The inactive X chromosome in female mammals, condensed into a clump.

The process where one of the X chromosomes in females is randomly inactivated.

The theory explaining random inactivation of X chromosomes in female embryos.

An adult female pattern where different cells express different alleles from X chromosomes.

A set of modifications on histones affecting gene expression.

Chemical changes to histones after protein synthesis.

Addition of an acetyl group to histones, often increasing gene expression.

Adding methyl groups to histones, can either activate or silence genes.

Phosphate groups added to histones affecting their role in transcription.

Groups of proteins that promote transcription, including histone acetyltransferase.

Enzyme that removes acetyl groups from histones, often silencing genes.

The arrangement and tightness of nucleosomes affecting DNA access.