M2

Question 1

what was chargaff findings

Answer 1

1. A=T, G=C
2. composition of DNA varies between species

Question 2

what 3 things were noted in the photo 51

Answer 2

1. Bases perpendicular to length of DNA molecule
   
   2. Helical structure
2. Double stranded

Question 3

what are the 5 main features of the waston-crick model

Answer 3

1. Sugar phosphate backbone is on outside
   
   2. Bases inside
   3. Stabilised by hydrogen bonds
   4. Double stranded helical structure
2. 2 polynucleotide strands are oriented in opposite directions

Question 4

what was provided in the waston-crick model

Answer 4

○ Stimulus for deciphering the genetic code
Possible mechanism for replication of DNA

Question 5

nucleotide monomer join with what to form polynucleotide

Answer 5

phosphodiester

Question 6

How does the semiconservative DNA allow genetic info to be passed to the next generation

Answer 6

replication to give a complementary strand

Question 7

why do we need cells to replicate

Answer 7

for injury, pregnancy, growth

Question 8

what direction does DNA (or RNA) synthesised in

Answer 8

5 to 3

Question 9

what direction does the parental template strand run in

Answer 9

3 to 5

Question 10

what does it mean by Aneuploidy

Answer 10

abnormal amount of particular chromosome e.g. down syndrome

Question 11

to progressive addition of new nucleotides (A,C,T or G) what enzyme achieves this

Answer 11

DNA polymerase 111

Question 12

what enzyme creates a staring point for nucleotide addition

Answer 12

primase enzyme make RNA primer

Question 13

what enzyme is involved in unwinding the helical double stranded DNA to give 2 parental templates

Answer 13

Helicase

Question 14

How dow you release tension generated by unwinding DNA helix (enzyme)

Answer 14

topoisomerase nicks and rejoins DNA strands

Question 15

what enzyme prevents unwound double-stranded helical DNA from reforming and to protect it from degradation

Answer 15

single stranded DNA binding protein

Question 16

what enzyme removes RNA primer and fills gap with DNA nucleotide

Answer 16

DNA polymerase 1

Question 17

what enzyme joins ends of newly synthesised fragments together

Answer 17

DNA ligase

Question 18

During replication what is used to repair DNA error

Answer 18

Exonuclease

Question 19

After replication what is used to repair DNA error

Answer 19

endonucleasue

Question 20

T/F does DnA replication show high accuracy - what enzyme shows this
DURING

Answer 20

true
DNA pol 111

Question 21

what enzyme has a proofreading mechanism
DURING DNA REP

Answer 21

DNA pol 111

Question 22

what direction is an incorrect base removed by
and with what during

Answer 22

3 to 5 direaction
exonuclease

Question 23

what are 3 things that can cause DNA damage

Answer 23

• incorrectly inserted bases not corrected by DNA pol 111
• radiation damage
• chemical modification bases

Question 24

in the polymerase chain reaction what DNA region will be copied

Answer 24

targeted

Question 25

what type of increase of DNA molecules occur in polymerase chain reaction

Answer 25

rapid exponential increase

Question 26

what are the 2 activities that DNA pol 1 carry out

Answer 26

1. RNase activity 2. DNA polymerase activity

Question 27

what type of enzyme is RNase

Answer 27

endonuclease enzyme

Question 28

RNase activity is responsible for recognise what and degrade what part

Answer 28

DNA and RNA hybrids degrades RNA part

Question 29

what joins together lagging strand (okazaki) fragments together, but also the newly syntehsised fragments from multiple replication bubbles (leading strands

Answer 29

DNA ligase

Question 30

why is replication semi discontinuous

Answer 30

leading (continous) lagging (discontinuous)

Question 31

what does it mean by nondisjunction and when does this occur

Answer 31

chromosomes failure to separate properly during meiosis (anaphase)

Question 32

what would someone with kinlefelter syndrome have for their sex chromosome - what appearance does this give

Answer 32

XXY female appearance in males

Question 33

someone with turner syndrome will have what sex chromosomes and what appearance does this give

Answer 33

XO male appearance on females

Question 34

if someone is polyploidy what does this mean

Answer 34

possession of multiple sets of chromosomes

Question 35

karpechenko is when

Answer 35

a polyplod 4n raddage is created

Question 36

what is inversion

Answer 36

reverses chromosomes in opposite order sequence

Question 37

what is translocation

Answer 37

segment is moved from one chromosome to a nonhomologous chromosome

Question 38

what chromosomes are involved in philadelphia translocation

Answer 38

9 and 22

Question 39

what chromosomes are involves in familial down syndrome

Answer 39

14 and 21

Question 40

individuals with familial down syndrome have what done to chromosome 21

Answer 40

translocation

Question 41

ransom inactivation of X chromosomes lead to what type of patterning

Answer 41

mosaic

Question 42

Why might we need to estimate frequencies of genotype in a population

Answer 42

1. to predict how many individuals will inherit a disease 2. to estimate proportion of individuals that are carriers of genetic diseases

Question 43

how can allele frequencies change

Answer 43

1. non random mating (imbreeding, assortive) 2. mutation 3. random genetic drift 4. bottle neck 5. founder effect 6. genetic flow 7. natural selection

Question 44

explain what a random genetic drift

Answer 44

random change in allele frequencies due to sampling error over generations

Question 45

What happens in the bottle neck effect

Answer 45

only a few species get through, rest gets trapped in the bottle

Question 46

explain the founder effect

Answer 46

new populations of same species being establish over the world

Question 47

2 birds: 1 has a small beak that feeds on soft food other has a large beak that can crack open a hard seed what time of selection is this

Answer 47

Disruptive selection - on either scales of the spectrum

Question 48

The change in genotype and phenotype depending on geographic change is called what

Answer 48

Cline spatial distribution of genetic variation

Question 49

what can non-coding DNA regions do

Answer 49

transcribe

Question 50

what are non-coding DNA involved in

Answer 50

gene expression

Question 51

what can cause disruption to gene expression

Answer 51

mutation

Question 52

why is the genetic code call triplet codon hypothesis

Answer 52

must be at least triplet based each condon (3 letters) encodes for one amino acids

Question 53

what codon specifically stop

Answer 53

UAA, UAG, UGA

Question 54

what codon specifically starts

Answer 54

AUG

Question 55

what is the adaptor molecule

Answer 55

transfer RNA = tRNA

Question 56

what can each tRNA molecule bind to and interact with

Answer 56

bind with amino acids interact with mRNA

Question 57

where does the tRNA attach to (attachment site)

Answer 57

3 end

Question 58

in translation what is mRNA used as

Answer 58

instructitions

Question 59

what are the three sites of the ribosomes

Answer 59

Accept peptide exit

Question 60

what are the 2 locations of the ribosomes

Answer 60

1. bound to rER 2. free in cytosol

Question 61

in translation there are 3 stages - what are these

Answer 61

1. Initiation 2. Elongation 3. Termination

Question 62

what do initation, elongation and termination all need

Answer 62

energy

Question 63

what are mendels two laws

Answer 63

1. law of segregation 2. law of independent assortment

Question 64

when are both mendals laws explain (mitosis or meiosis)

Answer 64

meiosis

Question 65

in independent assorment what is the type of cross done

Answer 65

dihybrid cross

Question 66

what is polymorphic

Answer 66

one gene - many alleles

Question 67

explain why white and red flowers can produce pink offspring - what is this called

Answer 67

incomplete dominance - means that blending is likely to occur

Question 68

what is the polygenic trait

Answer 68

phenotype have additive effect

Question 69

what is additive effect

Answer 69

e.g. skin colour where phenotype is determined by totoal number of colour producing allele

Question 70

what are Hemizygotes

Answer 70

people that only have one of the gene instead of two

Question 71

How are linked genes inherited

Answer 71

show bias towards parental genotypes

Question 72

How can we determine the order and loction of genes within a chromosme

Answer 72

by using recomination frequencies

Question 73

smaller distance between two genes means that what is the less likely will be formed between them

Answer 73

chiasma

Question 74

what is the relationship between distance and recombination frequency

Answer 74

near linear

Question 75

how does crossing over during meiosis explain recombination

Answer 75

Two chromatids cross over at random points and swap genetic material - simple cross

Question 76

how many chiasma are formed

Answer 76

during crossing over

Question 77

when does crossing over occur in meisosis

Answer 77

prophase 1

Question 78

in the Hardy weinberg equation p^2 referes to

Answer 78

homozygous dominant

Question 79

in the Hardy weinberg equation q^2 refers to

Answer 79

homozygous reccessive

Question 80

in the Hardy weinberg equation pq refers to

Answer 80

hetrozygous

Question 81

for an x linked trait what do females need to be to get the disease

Answer 81

homozygous recessive

Question 82

in a test cross what genotypes cross

Answer 82

unknown dominant phenotype x homozygous recessive

Question 83

what is pure bred and what are individuals have to be in a test cross

Answer 83

individual w/ known phenotype and genotype - always homozygous

Question 84

what is the ratio of incomplete assortment

Answer 84

1:1:1:1

Question 85

when a somatic cell is about to divided by mitosis this involves what chromosomes

Answer 85

replicated chromosomes