Organisation of the Human Genome

Question 1

The amount of DNA contained within a haploid nucleus or one half the amount in a diploid somatic cell of a eukaryotic organism is referred to as

Answer 1

the c value

Question 2

what is the c value measured in

Answer 2

picograms or kilobases

Question 3

what does the c value equate to in humans

Answer 3

3.2 x 10^9 bases or 6.55 picograms

Question 4

what is the genome defined as

Answer 4

the complete dna sequence of an organism

Question 5

what is the expectation of the c value

Answer 5

proportional to the genetic complexity (number of genes) of an organism

Question 6

the number of genes in bacterial and archaeal genomes correlates with

Answer 6

the genome size and the complexity of the organism

Question 7

does the number of genes in a eukaryote correlate with the genome size or the complexity of the organism

Answer 7

nope

Question 8

what is the c value paradox

Answer 8

the lack of relationship between the dna content (c-value) of an organism and its coding potential

Question 9

what percentage of the human genome consists of introns

Answer 9

24%

Question 10

what percentage of the human genome consists of exons - protein coding sequences

Answer 10

1.2%

Question 11

8.5% of the human genome is made of

Answer 11

protein binding sequences

Question 12

on heating DNA what happens to it and what is this called

Answer 12

the strands separate and this is called DNA melting

Question 13

melting involves what to happen to the DNA

Answer 13

progressive breaking of base pairs in the double helix

Question 14

the melting temperature is determined by what?

Answer 14

the base composition of the DNA

Question 15

which base pairs melt at a lower temperature

Answer 15

A:T base pairs melt at lower temperatures than G:C

Question 16

the temp at which DNA is half unfolded is referred to as

Answer 16

the melting temperature Tm

Question 17

the higher the G:C ratio the higher the

Answer 17

Tm

Question 18

DNA melting can be followed in a

Answer 18

spectrophotometer

Question 19

at what temperature is the chance in absorbance measured at in a dna melting curve

Answer 19

260nm

Question 20

nucleotide bases absorb UV light at a wavelength of

Answer 20

260nm

Question 21

if melted dna is rapidly cooled complementary strands remain

Answer 21

separated

Question 22

if melted dna is slowly cooled then what will happen to the complementary strands

Answer 22

they will pair up again

Question 23

what is the process of the strands pairing up again called

Answer 23

dna reannealing or renaturation

Question 24

dna reannealing is the basis of which technique

Answer 24

dna hybridisation

Question 25

what four factors is the rate of dna reannealing measured by

Answer 25

concentration, length, composition and complexity

Question 26

the extent of dna reannealing is governed by

Answer 26

time

Question 27

dna reannealing is measured by a

Answer 27

c0t value

Question 28

what is a c0t value and what units

Answer 28

concentration x time in mols per second

Question 29

the lower the c0t value the

Answer 29

less complex

Question 30

dna reanealling experiments show that prokaryotic genomes are

Answer 30

kinetically simple

Question 31

prokaryotic dna reanneals as if it were a

Answer 31

single unique length of dna with no sequence repeats

Question 32

dna reannealing experiments show that eukaryotic genomes are

Answer 32

kinetically complex

Question 33

eukaryotic genomes contain

Answer 33

several classes of dna

Question 34

the fast component in c0t curve is

Answer 34

highly repeated dna sequences

Question 35

the intermediate component of a c0t curve is

Answer 35

moderately repeated dna sequences

Question 36

the slow component of a c0t curve is

Answer 36

non-repetitive or single copy dna sequneces

Question 37

highly repetitive dna is present in almost all

Answer 37

higher eukaryotic genomes

Question 38

what c0t range does highly repetitive dna have

Answer 38

low c0t range 10-4 to 10-2

Question 39

highly repetitive dna doesnt have coding function, what does it do instead?

Answer 39

provide a structural function

Question 40

repeats arranged head to tail in blocks of various lengths are called

Answer 40

tandem arrays

Question 41

repeated regions interspersed within the chromosome are called

Answer 41

interspersed regions

Question 42

what is the longest tandem array known

Answer 42

human alphoid dna

Question 43

major classes of tandemly repeatedly human dna are classified according to size into which three classes

Answer 43

satellite, minisatellite and microsatellite

Question 44

most random sequence dna has a similar buoyant density and forms part of the

Answer 44

main band

Question 45

if one short sequence is repeated many times in a tandem array, it forms what in the equilibrium densitry centrifugation experiment

Answer 45

satellite DNA band

Question 46

which two ways allow expansion of tandemly repeated human dna?

Answer 46

unequal crossing over and replication slippage

Question 47

what does unequal crossing over result in

Answer 47

one recombinant with a deletion of material and one with a duplication

Question 48

what does a replication slippage result in

Answer 48

each slippage adds one repeating unit to the daughter strand

Question 49

where are microsatellites found

Answer 49

widely disperesed over the chromosome

Question 50

where are minisatellites found

Answer 50

telomere

Question 51

tandem repeats of which sequence minisatellite are found at the telomeres

Answer 51

TTAGGG

Question 52

the centromere contains

Answer 52

various satellite components

Question 53

structural intermediate repetitive DNA contains diff classes, these are

Answer 53

retrovirus/LTR retrotransposons, LINEs and SINES and then we have coding DNA

Question 54

The LINE1 element has two open reading frames which are

Answer 54

ORF1 and ORF2

Question 55

ORF1 encodes what

Answer 55

a rna binding protein

Question 56

ORF2 encodes

Answer 56

a protein with both endonuclease and reverse transcriptase activities

Question 57

Lines have a RNA mediated

Answer 57

transposition event

Question 58

what does a retrovirus encode for

Answer 58

integrase and reverse transcriptase activities

Question 59

retrovirus is a rna mediated

Answer 59

transposition event

Question 60

give an example of a sines

Answer 60

alu repeat

Question 61

infromational intermediate repetitive dna exists and contains genes for

Answer 61

histones, collagen, keratins, rRNA, tRNA

Question 62

slow annealing dna is

Answer 62

unique

Question 63

protein coding dna makes

Answer 63

mRNA