Molecular

Question 1

DNA exists as ____ to fit into nucleus

Answer 1

Chromatin

Question 2

Beads on a string…

Answer 2

Negatively charged DNA loops twice around positively charged histone octamers.

Question 3

Histones are rich in what amino acids

Answer 3

Lysine and arginine

Question 4

What binds to the nucleosome and “linker DNA” to stabilize chromatin fibers?

Answer 4

H1

Question 5

In Mitosis, DNA condenses into ___.

Answer 5

Chromosomes

Question 6

Histone synthesis occurs during what phase of mitosis

Answer 6

S phase w/DNA

Question 7

Highly condensed Chromatin that is transcriptionally inactive and sterically inaccessible?

Answer 7

Heterochromatin. Barr bodies (inactive X chromosomes) are an example.
Appears Darker on EM

Question 8

Less condensed, transcriptionally active, and sterically accessible chromatin

Answer 8

Euchromatin
Eu= true (truly transcribed)
Appears lighter on EM

Question 9

Methylation makes DNA _____?

Answer 9

Mute!

Cytosines and adenine on the template strand will be methylated in DNA replication. This allows mismatch repair enzymes to distinguish between new and old strands in prokaryotes

Question 10

Histone methylation _____ ____ _____.

Answer 10

Represses DNA transcription.

But, can activate in some cases depending on methylation location.

Question 11

Histone acetylation ____ ____ ____.

Answer 11

Relaxes DNA coiling

This allows transcription to take place.