Basics

Question 1

Euchromatin

Answer 1

light bands, transcriptionally active, less tightly condensed

Question 2

Heterochromatin

Answer 2

dark bands, transcriptionally inactive

Question 3

Facultative heterochromatin

Answer 3

inactive but can become active (eg inactive X chromosome in females)

Question 4

Constitutive heterochromatin

Answer 4

always inactive (centromeric regions, distal long arm of Y, short arms of actrocentrics)

Question 5

histones

Answer 5

H2A, H2B, H3, H4

Question 6

basic unit of DNA condensation

Answer 6

nucleosome

Question 7

Cells can be synchronized by blocking the _ phase

Answer 7

S

Question 8

Achromatic

Answer 8

Lens that has been corrected for 2 colours

Question 9

Apochromatic

Answer 9

Lens that has been corrected for 3 colours and spherical aberration

Question 10

Substage condenser diaphragm

Answer 10

controls contrast, numerical aperture, ultimate resolution

Question 11

when the substage condenser diaphragm is wide open ___ is greatest and ___ is least

Answer 11

resolution is greatest, contrast is least