Mendelian Inheritance

Question 1

Will 2 restriction target sites on the same DNA strand be compatible?

Answer 1

No

Question 2

The eukaryotic metaphase chromosomes will consist of 2…

Answer 2

sister chromatids. This happens by 1 chromatid opening and being replicated to form an identical sister

Question 3

Cohesin attaches to…

Answer 3

the 2 sister chromatids when the replica has been made. This is designed to keep things organised

Question 4

The centromere is..

Answer 4

a part of the chromosome which is known as the primary constriction site where proteins bind to initially

Question 5

A telomere is

Answer 5

The end parts of chromosomes. There are 2 on each one

Question 6

DNA is 1 single molecule running from….

Answer 6

one telomere to another

Question 7

Centromeres are where…

Answer 7

chromosomes attach, via the kinetochore, to the mitotic spindle during metaphase.

Question 8

The centromere divides the chromosome…

Answer 8

into 2 arms. These are known as the p arm (shorter) and the q arm (longer)

Question 9

DNA of each chromatid is packaged tightly with proteins to form….

Answer 9

chromatin

Question 10

During interphase (s phase)

Answer 10

DNA is replicated

Question 11

During metaphase…

Answer 11

DNA is condensed to form chromosomes

Question 12

Cohesin holding sister chromatids must be broken at the centromere….

Answer 12

after the arms

Question 13

Telomeres have 2 problems.. these are

Answer 13

free ends and telomere shortening

Question 14

New DNA is synthesised in the…

Answer 14

5 prime to 3 prime direction.

Question 15

The lagging strand is synthesised in…

Answer 15

short stretches

Question 16

telomeric repeats are

Answer 16

a bit of DNA which is repeated. These are 6 nucleotides long but take up a reasonable amount of kb. These repeats are recognised by a protein called shelterin which aids in the folding of the strand.

Question 17

Chromosomes 1-22 exist as

Answer 17

homologous chromsomes.

Question 18

Females have a homologous pair of…

Answer 18

x chromosomes

Question 19

Males have a non- homologous pair of

Answer 19

sex chromosomes

Question 20

Issues with chromosome 21 (having an extra 1) can result in

Answer 20

Down’s syndrome

Question 21

cri-du-chat syndrome is

Answer 21

related to the cry that the baby makes. This happens due to the partial deletion of 5p (part of chromosome 5)

Question 22

Fragile X syndrome

Answer 22

results in defects from x chromosome genes. Occurs due to issues with the secondary constriction on part of the arm. Particular genes affected include the FMR1 gene

Question 23

One of the benefits of telomeres forming is that…

Answer 23

it ensures that cells remain mortal, hence, it actually suppresses diseases such as cancer.

Question 24

how do kinetochores know where centromeres are?

Answer 24

Centromeres have different histones which make up the chromatin there

Question 25

Most of the eukaryotic genome is...

Answer 25

non- coding (i.e. they dont code for proteins or anything useful)

Question 26

Our genome contains...

Answer 26

unique and repetitive sequences

Question 27

Some genes are also...

Answer 27

present more than once in the genome

Question 28

In eukaryotic gene expression...

Answer 28

transcription and translation can never be coupled

Question 29

Each eukaryotic gene has its own transcription unit with a promoter at the

Answer 29

5' end

Question 30

each gene is transcribed on its own specifically in...

Answer 30

eukaryotes

Question 31

Multiple transcription factors recognise specific DNA sequence elements within the.....

Answer 31

gene promoter

Question 32

The TATA box is...

Answer 32

the sequence of DNA where the TBP exists and the Transcription factor binds

Question 33

RNA polymerase is recruited by...

Answer 33

transcription factors in eukaryotes

Question 34

In prokaryotes, RNA polymerase...

Answer 34

identifies the promoter on its own.

Question 35

The steps of mRNA processing is

Answer 35

1. capping - this is where mRNA's have a 5 prime cap for ribosome binding 2. slipicing - this is where the introns are spliced and the exons are brought together which maintains the open reading frame 3. Polyadenylation - a polyA tail is added to the 3 prime end for stability

Question 36

splicing occurs in the

Answer 36

spliceosome

Question 37

The spliceosome recognises...

Answer 37

the boundary between the intron and exon nucleotide

Question 38

Only pol II coding genes are

Answer 38

polyadenylated and capped

Question 39

Duchenne Muscular dystrophy

Answer 39

is a progressive muscle degeneration, and it comes across due to defects in dystrophin gene, it is sex linked, there is a milder form known as BMD. Dystrophin protein sits in the membrane that surrounds muscle fibres, and protects the membrane. DMD occurs due to a deleted exon, which therefore results in the protein being non functional.

Question 40

non coding genes could possibly have a function

Answer 40

It is possible that some of the non coding genome does work to make RNA however more investigation is needed. Also having non- coding genes are responsible for alternative splicing.

Question 41

Dominant negative mutations....

Answer 41

is where the mutant allele product interfering with the function of the unaffected allele.

Question 42

Haploinsufficiency is where ...

Answer 42

the gene product is insufficient because of the mutant allele, and this prevents the normal phenotype.

Question 43

Dominance is a property...

Answer 43

of the phenotype

Question 44

loss of function allele is normally

Answer 44

recessive

Question 45

co dominant alleles each produce

Answer 45

a phenotype

Question 46

incomplete dominance arises when two alleles produce

Answer 46

an incomplete phenotype

Question 47

Mammalian coat colour results from the interaction of atleast

Answer 47

5 separate genes

Question 48

complex or multifactorial traits result from

Answer 48

participation in the same or overlapping pathways

Question 49

genome wide association studies

Answer 49

exploits naturally occuring linkage disequilibrium