Chromosome structure

Question 1

Chromosome

Answer 1

Condensed thread-like structure consisting of proteins and a molecule of DNA.

Question 2

Centromere

Answer 2

A constricted point in a chromosome which divides a chromosome into two arms.

Question 3

P-Arm

Answer 3

Short arm of a chromosome

Question 4

Q-Arm

Answer 4

Long arm of a chromosome

Question 5

Sister Chromatids

Answer 5

“One half” of a chromosome.

Question 6

Euchromatin

Answer 6

During interphase, chromatin that is being actively expressed

Question 7

Heterochromatin

Answer 7

During interphase, chromatin that is not being expressed

Question 8

Histones

Answer 8

Small, positively charged proteins that bind to DNA in order to compact it. (H1, H2A, H2B, H3, H4).

Question 9

Nucleosome

Answer 9

Eight histone proteins with 1.65 times DNA wrapped around it. 10 nm fiber.

Question 10

Chromatosome

Answer 10

A nucleosome with an H1 histone, a “pin” that holds it together.

Question 11

30 nm fiber

Answer 11

Nucleosomes that coil into a 30 nm wide structure.

Question 12

300 nm Loops

Answer 12

30 nm fibers that coil into loops.