L4 Chromosome Structure

Question 1

What do diploid eukaryotic cells contain

Answer 1

two copies of each chromosome

Question 2

What can individual chromosomes be easily distinguished

Answer 2

metaphase of mitosis

Question 3

Karotype

Answer 3

organised representation of all chromosomes at metaphase

Question 4

Describe the organisation of individual chromosomes in interphase

Answer 4

occupy distinct subnuclear terriotories

Question 5

Chromosome

Answer 5

highly coiled fibre of chromatin

Question 6

Types of chromatin

Answer 6

euchromatin, heterochromatin

Question 7

Nucleosome

Answer 7

building material of chromosomes

Question 8

Types of histone

Answer 8

4 distinct types

Question 9

Core histones

Answer 9

protein subunit of nucleosome

Question 10

Function of histone tails

Answer 10

interact with proteins, facilitate regulation of chromatin

Question 11

H1

Answer 11

linker histone

Question 12

Function of H1

Answer 12

straps DNA onto histone octamers - limits DNA movement

Question 13

What does H1 facilitate

Answer 13

establishment of transcriptionally silent heterochromatin

Question 14

Interphase chromatin

Answer 14

set of dynamic fractal globules

Question 15

Nuclear periphery in interphase cells composition

Answer 15

transcriptionally inactive DNA

Question 16

Heterochromatin

Answer 16

transcriptionally silent

Question 17

Inner part of the nucleus in interphase cells

Answer 17

RNA transcripts, transcriptionally active genes

Question 18

Telomere

Answer 18

DNA sequences at ends of linear chromosome

Question 19

Telomere function

Answer 19

maintain chromosomal integrity

Question 20

Replication origin

Answer 20

DNA sequence, initiation of DNA replication

Question 21

Centromere

Answer 21

DNA sequences, kinetochore assembly

Question 22

Centromere function

Answer 22

Mediate chromosome segregation

Question 23

Kinetochore

Answer 23

protein complex

Question 24

Kinetochore function

Answer 24

binds microtubules in mitotic spindle

Question 25

Telomerase

Answer 25

DNA polymerase that replicates telomeres

Question 26

True or False - telomeres are double stranded

Answer 26

false

Question 27

Two forms of kinetochore

Answer 27

inner and outer plate

Question 28

Inner kinetochore plate function

Answer 28

binds to chromatin containing alpha satellite DNA

Question 29

Kinetochore outer plate function

Answer 29

binds to protein components of mitotic spindle

Question 30

What do centromeres contain

Answer 30

alpha satellite DNA repeats

Question 31

Alpha satellite DNA repeats function

Answer 31

form condensed heterochromatin with histone octamers

Question 32

CENP-A

Answer 32

specialised histone in centromeric chromatin

Question 33

CENP-A function

Answer 33

connects inner kinetochore plate to methylated histones

Question 34

H3-K4me

Answer 34

methylated histone

Question 35

H3-K4me function

Answer 35

hold sister chromatids together

Question 36

Kinetochore in yeast

Answer 36

Hollow cylinder / basket

Question 37

Kinetochore in yeast function

Answer 37

links single nucleosome of centromeric chromatin to single microtubule

Question 38

Relationship between complex organisms and protein coding genes

Answer 38

More complex organisms, more protein coding genes, more non protein coding DNA

Question 39

Transposons

Answer 39

mobile repeated DNA sequences

Question 40

Types of transposons

Answer 40

DNA transposons, Retroviral retrotransposons, Non-retroviral polyA retrotransposons

Question 41

DNA transposon movement

Answer 41

cut and paste mechanism, without self duplication

Question 42

Requirements of DNA transposon movement

Answer 42

transposase

Question 43

DNA transposon discovery

Answer 43

Maize by Barbara McClintock

Question 44

Retroviral transposons function

Answer 44

replicate via RNA intermediates, produce new DNA copies - integrate at new genomic locations

Question 45

Retroviral transposon requirement

Answer 45

self encoded reverse transcriptase

Question 46

non-retroviral retrotransposons

Answer 46

replicate via RNA intermediate, copy and paste

Question 47

non-retroviral retrotransposon requirement

Answer 47

retrotransposon encoded reverse transcriptase

Question 48

TRUE or FALSE - most transposons are defective

Answer 48

true

Question 49

Large numbers of transposable elements are found in...

Answer 49

genomes of more complex organisms

Question 50

How much of the human genome is made up of transposons

Answer 50

around 50%