Genome Structure and Function

Question 1

Gene

Answer 1

Sequence of nucleotides forming part of nucleotide coding for protein (exons)

Question 2

Exome

Answer 2

Coding DNA of the genome

Question 3

Epigenome

Answer 3

chemical modifications attached to DNA controlling their expression

Question 4

What will cause a chromosome to stay in tact?

Answer 4

Must have telomere and centromere

Question 5

chromosome structure?

Answer 5

p arm (shorter), q arm (longer) attached by centromere

Question 6

four categories of chromosomes

Answer 6

metacentric, sub-metacentric, acrocentric, telocentric

Question 7

metacentric

Answer 7

bang in middle

Question 8

sub-metacentric

Answer 8

off centre

Question 9

acrocentric

Answer 9

tiny p arm, long q arm only contains genes for coding RNA molecules. 5 autosomal acrocentric chromosomes have the same p arms so you don’t need all of them.

Question 10

telocentric

Answer 10

no p arm

Question 11

three ways to distinguish chromosomes

Answer 11

where the centromere is, size, banding pattern

Question 12

What is Chromatin

Answer 12

DNA + Histones = Chromatin

Question 13

What are chromosomes made of?

Answer 13

Chromatin

Question 14

What is a nucleosome

Answer 14

octamer of histones

Question 15

charge of DNA

Answer 15

negative

Question 16

Charge of histones

Answer 16

positive

Question 17

two states of chromatin

Answer 17

euchromatin and heterochromatin

Question 18

what is the structure of euchromatin

Answer 18

extended, dispersed, gene is expressed

Question 19

what is the structure of heterochromatin

Answer 19

highly condensed, gene not expressed

Question 20

how do the two types of chromatin show up in G banding?

Answer 20

Euchromatin: Light
Heterochromatin: Dark

Question 21

what is the function of the centromere?

Answer 21

• keep sister chromatids together
• attach to microtubules in division
• rich in heterochromatin

Question 22

what is the function of the telomeres?

Answer 22

• prevent degradation

- repetitive sequence

Question 23

sequence of the telomeres?

Answer 23

TTAGGG

Question 24

What is the genome?

Answer 24

20,000 genes
3 billion base pairs
= mitochondrial + nuclear DNA

Question 25

what is the exome

Answer 25

Parts of the genome that code for protein (only exons)

Question 26

Nuclear genome

Answer 26

22 pairs of autosomes

1 pair of sex chromosomes

Question 27

mitochondrial genome

Answer 27

much smaller, multiple copies

Question 28

how many coding genes in mitochondrial genome

Answer 28

13

Question 29

how many non-coding genes in mitochondrial genome

Answer 29

24 (only code for RNA)

Question 30

pattern of mitochondrial inheritance?

Answer 30

MATERNAL! only the egg/ova provides mitochondria

Question 31

what is the strucutre of DNA

Answer 31

phosphate + deoxyribose sugar + nitrogenous base

Question 32

what are the four nitrogenous bases?

Answer 32

Adenine
Guanine
Cytosine
Thymine

Question 33

What are the purine bases?

Answer 33

Adenine and Guanine

Question 34

What are the pyrimidine bases?

Answer 34

Cytosine and Thymine

Question 35

Which bases pair together?

Answer 35

A + T

G + C

Question 36

How many hydrogen bonds between A+T

Answer 36

2

Question 37

How many hydrogen bonds between G+C

Answer 37

3

Question 38

how does epigenome affect gene activity?

Answer 38

Alter chromatin structure
Recruit histone modifiers
Repress transcription
Genome-wide pattern established at fertilisation
Important for differential gene expression (transcription)
Responds to environmental cues (cellular and external)

Question 39

examples of epigenome alterations

Answer 39

E.g. DNA methylation, histone acetylation