DNA 2

Question 1

State the length of total DNA and the diameter of a nucleus in which is resides

Answer 1

2 meters of DNA compressed into about a 10 micrometer (x 10^-6m) diameter nucleus

Question 2

Define nucleosome

Answer 2

DNA and histones together (DNA wrapped around histone) its the smallest functional unit of chromatin

Question 3

Describe all components of a nucleosome

HELP

Answer 3

DNA, histones, octamer

Question 4

State the length in bp of DNA wrapped around a histone , including the number of turns

Answer 4

146 bp of DNA wrapped 1 3/4 turns around octamer. His time protein H1 holds DNA in place

Question 5

Protein that holds DNA to the octamer

Answer 5

Histone protein H1

Question 6

How else does DNA adhere to the histone octamer

Answer 6

Positive octamers bond to negatively charged DNA

Question 7

Role of linker DNA and their maximum length

Answer 7

To link the nucleosomes together. Up to 80 bp

Question 8

Define chromatin

Answer 8

Substance distributed in nucleus of cell that condenses into chromosomes during cell division. Made up of DNA and protein histones

Question 9

How does chromatin form

Answer 9

Histone protein H1 holds nucleosomes together. Additional scaffolding proteins used to condense chromatin into tightly packed chromosomes of metaphase

Question 10

What phase of cell cycle does chromatin exist

Answer 10

Interphase

Question 11

Differentiate chromatin from chromosomes by cell cycle phase, compaction, and proteins used

Answer 11

Chromatin: interphase, nucleosomes condense into chromatin fiber, histone protein H1 holds nucleosomes together

Chromosome: metaphase, scaffolding proteins used to condense chromatin into tightly packed chromosomes, scaffolding proteins

Question 12

Identify phase in cell cycle where DNA is condensed to the level of nucleosome
HELP

Answer 12

Interphase

Question 13

Identify phase in cell cycle where DNA is condensed to the level of chromatin
HELP

Answer 13

Interphase