Chapter 11

Question 1

Negative supercoiling

Answer 1

DNA is understated

Question 2

Positive supercoiling

Answer 2

DNA is overrotated

Question 3

Supercoiling is achieved what enzyme

Answer 3

Topoisomerase

Question 4

DNA is usually _____ supercoiled

Answer 4

Negatively

Question 5

Eukaryotice chromosomes must be _____ for transcription but _____ for cell division

Answer 5

Accessible, condensed

Question 6

What is chromatin?

Answer 6

Complex of DNA and associated proteins, mostly histones

Question 7

Euchromatin

Answer 7

Decondensed during interphase

Question 8

Heterochromatin

Answer 8

Chromatin that is always condensed

Question 9

Constitutive Heterochromatin

Answer 9

In all cells (centromere and telomeres)

Question 10

Facultative Heterochromatin

Answer 10

In specific cells or developmental stages

Question 11

What are nucleosomes?

Answer 11

Core of DNA-wrapped histones. Tails extend out. Strong positive charge.

Question 12

What is a polytene chromosome?

Answer 12

Found in drosophila larvae.

Question 13

Chromosome puffs

Answer 13

Regions of relaxed DNA actively transcribed in drosophila larvae

Question 14

Centromeres

Answer 14

Constructed region of chromosome that kinetochores and spindle fibres attach to

Question 15

Centromeres made up of _____ euchromatin

Answer 15

hetero

Question 16

Telomeres

Answer 16

Protective caps for linear chromosome ends

Question 17

C value

Answer 17

Amount of DNA per cell

Question 18

Differences in chromosomes across species

Answer 18

C value
Gene density within chromosome
Base composition

Question 19

Unique Sequence DNA

Answer 19

Only a few copies per cell

Includes non-coding DNA of unknown function

Question 20

Gene family

Answer 20

Group of related genes

Question 21

Moderately repeated DNA

Answer 21

Thousands of times in genome

Question 22

Highly repeated DNA

Answer 22

Occurs millions of times in a genome; 10bp or less

Question 23

Which organelles contain DNA

Answer 23

Mitochondria and chloroplasts

Question 24

Endosymbiont Theory

Answer 24

Anaerobic eukaryote engulfed aerobic prokaryote, resulting in the prokaryote becoming mitochondria

Question 25

Uniparental Inheritance

Answer 25

Traits inherited form one parent (usually due to cytoplasmic inheritance)

Question 26

Why is mtDNA inherited from mother in animals, and not father?

Answer 26

Sperm are too small to carry DNA other than nuclear. Autophagy results in mitochondria being disallowed in the embryo.

Question 27

Heteroplasmic cells

Answer 27

Organelles segregate randomly

Question 28

Homoplasmic cells

Answer 28

A cell does not inherit a mixture of mutant and wild-type organelles; inherits only one type