Lesson 3 - Properties of Genetic Material

Question 1

genetic material should be FAIRS

Answer 1

F - flexible / respond to external signals
A - altered / generate genetic diversity
I - information
R - replicated and transmitted accurately
S - stable (very)

Question 2

genetic material should be flexible or …?

Answer 2

respond to external signals

Question 3

genetic material should be altered or …?

Answer 3

generate genetic diversity

Question 4

two sections of the chromosome

Answer 4

1. p arm
2. q arm

Question 5

p in p arm meaning

Answer 5

petit

Question 6

short arm of the chromosome

Answer 6

p arm

Question 7

long arm of the chromosome

Answer 7

q arm

Question 8

• appears as a constricted region of a chromosome
• plays a key role in helping the cell divide up its DNA during division
• the region where the cell’s spindle fibers attach.

Answer 8

centromere

Question 9

• region of repetitive DNA sequences at the end of a chromosome
• protect the ends of chromosomes from becoming frayed or tangled
• Each time a cell divides, they become slightly shorter

Answer 9

telomere

Question 10

composed of DNA and associated proteins

Answer 10

chromatin

Question 11

two types of proteins in chromatin

Answer 11

1. histone
2. non-histone chromosomal proteins

Question 12

small, well-defined, basic proteins

Answer 12

histone

Question 13

include diverse structural, enzymatic and regulatory proteins

Answer 13

non-histone chromosomal proteins

Question 14

example of non-histone chromosomal proteins

Answer 14

• transcription factors
• replisomes

Question 15

two types of chromatin

Answer 15

1. heterochromatin
2. euchromatin

Question 16

typically highly condensed, gene-poor, and transcriptionally silent

Answer 16

Heterochromatin

Question 17

less condensed, gene-rich, and more accessible to transcription.

Answer 17

euchromatin

Question 18

epigenetic mark

Answer 18

methyl

Question 19

• flexible regions that flank both ends of the histone fold
• responsible for the formation of stable H2A–H2B and H3–H4 dimers, and the histone octamer is composed of two H2A–H2B dimers and two H3–H4 dimers

Answer 19

Histone tails

Question 20

repeating units of chromatin composed of DNA and histones

Answer 20

nucleosome

Question 21

Classes of histones

Answer 21

• H1
• H2A
• H2B
• H3
• H4

Question 22

other term of H1

Answer 22

linker histone

Question 23

• bind to linker DNA and are involved in the higher-order condensation of the chromatin
• control the accessibility of linker DNA between two neighbor nucleosomes to DNA-binding proteins and regulate chromatin folding

Answer 23

Linker H1 histones

Question 24

complex together and act as a spool which the DNA wraps around

Answer 24

H2A, H2B, H3, and H4

Question 25

octamer

Answer 25

2 copies of each histone (H2A, H2B, H3, H4)

Question 26

Why is DNA of histone highly conserved

Answer 26

if there are changes, it leads to cell death

Question 27

around 147 bp supercoiled DNA wrapped twice around a __

Answer 27

histone

Question 28

how many base pairs of DNA are supercoiled in the histone

Answer 28

147 bp

Question 29

histone H1 are referred to as __ __

Answer 29

linker DNA

Question 30

histone H1 associates with

Answer 30

linker DNA

Question 31

how many bp are there in linker DNA

Answer 31

38-53 base pairs

Question 32

purpose of linker DNA

Answer 32

connects one nucleosome to the next

Question 33

histone H1 runs down the center of the coil acting as __

Answer 33

stabilizer

Question 34

nucleosomes are also described as

Answer 34

"beads on a string"

Question 35

thickness of chromatin

Answer 35

30nm

Question 36

two models of chromatin arrangement

Answer 36

1. solenoid model 2. zig-zag model

Question 37

- characterized by interactions between consecutive nucleosomes - helical loop

Answer 37

solenoid model

Question 38

implies interactions between alternate nucleosomes

Answer 38

zigzag model

Question 39

represents the basic structural unit of eukaryotic chromatin associated with DNA replication, gene expression and higher order packaging

Answer 39

loop domain

Question 40

Summary: Levels of Chromatin Packing

Answer 40

1. DNA double helix 2. DNA wrapped around histone 3. nucleosomes coiled into a chromatin fiber 4. further condensation of chromatin 5. duplicated chromosome