Eukaryotic Chromosomes Organization (BIO)

Question 1

Histones and non-histone proteins that associate with DNA to either package it into chromosomes, or release it to undergo transcription

Answer 1

Chromosomal proteins

Question 2

A DNA sequence that does not repeat itself

Holds most of the genetic information and low mutation rate

Answer 2

Single Copy

Question 3

A DNA sequence that continues to repeat itself
Mostly found near the centromeres and telomeres
May have some genes (centromere)
No genes (Telomeres)
Higher rate of mutation

Answer 3

Repetitive DNA

Question 4

over or under-winding of a DNA strand that disallows transcription
Occurs in the packaging of DNA

Answer 4

Supercoiling

Question 5

Tightly packed DNA that disallows transcription or at least moderates it

Answer 5

Heterochromatin

Question 6

unpacked DNA that is open for transcription

Answer 6

Euchromatin

Question 7

No genes

Answer 7

telomeres

Question 8

some genes

Answer 8

centromeres

Question 9

Model of the transcriptional regulation of the lac operon by lac repressor
When a lac repressor binds to the operator, which lies upstream of the lac gene, transcription of the gene by RNA polymerase is blocked

Answer 9

Jacob-Monod Model

Question 10

In bacteria genes are often found in operons - more than one gene in an operon and are transcribed as a group
Each operon has a regulatory sequence
Operons can be either inducible or repressible - small molecules can bind and either activate the operon or deactivate it

Answer 10

Gene Repression in Bacteria

Question 11

Regulatory protein is an activator

Answer 11

Positive control in bacteria