Cellular control

Question 1

Chromosome mutations

Answer 1

affect the whole chromosome or number of chromosomes in a cell.

Question 2

chromosome mutation deletion

Answer 2

a section of chromosome breaks off and is lost in the cell.

Question 3

chromosome mutation duplication

Answer 3

sections get duplicated on a chromosome

Question 4

chromosome mutation translocation

Answer 4

a section of one chromosome that breaks off and joins to a non-homologous chromosome (unlike chiasmata)

Question 5

inversion

Answer 5

a section of the chromosome breaks off, gets inverted and rhen joins back onto the chromosome.

Question 6

chromosome mutations can also…

Answer 6

affect the number of chromosomes. this is called aneuploidy

Question 7

when chromosomes dont separate properly?

Answer 7

non- disjunction

Question 8

operon

Answer 8

a group of genes under the control of the same operating system and expressed at the same time.

Question 9

heterochromatim

Answer 9

tightly wound DNA, condensed chromosomes

Question 10

euchromatin

Answer 10

DNA is loosely wound, here DNA transcription and DNA synthesis can take place.

Question 11

Histone modification

Answer 11

adding acetyl or phosphate groups reduces positive charge of histones, negative DNA coils less tightly.

adding methyl group (methylation) increases positivity of histones so negative DNA winds more tightly.

Question 12

lac z

Answer 12

beta galactosidase

Question 13

lac y

Answer 13

lactose permease

Question 14

lac a

Answer 14

transactylase

Question 15

lac I

Answer 15

codes for repressor protein

Question 16

binding site of RNA polymerase

Answer 16

Promotor

Question 17

Transcription factors

Answer 17

protiens that control gene expression by stimulating or inhibiting the transcription of genes.

Question 18

Mutation of a singular base is called

Answer 18

a point mutation

Question 19

mutagenic agents

Answer 19

• benzene
• bromine
• ionising radiation
• UV radiation

Question 20

natural and non environmental cause of DNA

Answer 20

errors in DNA replication.

Question 21

Aneuploidy

Answer 21

Aneuploidy is the presence of an abnormal number of chromosomes in a cell

Question 22

non- disjunction

Answer 22

chromosome pairs do not seperate properly

Question 23

4 different chromosome mutations

Answer 23

• translocation
• inversion
• deletion
• duplication

Question 24

3 types of regulatory molecules

Answer 24

• repressors - decrease transcription
• activators - increase transcription
• inducers - activate or repress transcription depending

Question 25

Post translational

Answer 25

- diff groups, i.e. methyl, phosphate etc can be added - cAMP can activate or inactivate protiens in the cell.

Question 26

Lac operon operates in the ...

Answer 26

e.coli bacteria

Question 27

what happens when glucose is not present (lac operon)

Answer 27

lactose binds to repressor protein, causing a conformational change, the tertiary structure of the repressor protein changes, repressor protein is released from operator

Question 28

Post transcription regulation

Answer 28

- regular old RNA splicing, removing introns - or alternative splicing, removing different combinations of introns and exons to form many different protiens from the same gene - modifications to RNA stability determinehow mych protien is made. I.E more stable, more RNA to be translated, more protien.

Question 29

Histone acetylation

Answer 29

results in loose packing

Question 30

histone methylation

Answer 30

Results in tightly packed DNA

Question 31

homeotic genes

Answer 31

control "shape design" of organisms

Question 32

Morphogenesis

Answer 32

process that causes an organism to form its shape

Question 33

homeobox genes

Answer 33

- are a subset of homeotic genes - CONTAIN a homeobox

Question 34

Homeobox sequence

Answer 34

- 180 nucleotides (base pairs) - 60 amino acids - codes for homeodomain

Question 35

a homeodomain

Answer 35

- is a protien - is coded for by a homeobox - contains 3 alpha helixes, helix, turn helix.

Question 36

What is so special about the helix turn helix structure of the homeodomain protein

Answer 36

it allows the homeodomain to act as a transcription factor and bind to DNA.

Question 37

put the homeobox thingy altogether...

Answer 37

homeobox gene with a homeobox sequence inside---> protien with a homeodomain---> homeodomain helix-turn- helix binds to DNA to act as a transcription factor

Question 38

type of homeobox genes only found in animals

Answer 38

HOX GENES

Question 39

What the fuck to hox genes do???

Answer 39

correct positioning of body parts in bilateral animals

Question 40

Bilateral

Answer 40

line if symmetry split veryically down centre

Question 41

Hox genes arranged in...

Answer 41

hox clusters

Question 42

fun fact about hox genes

Answer 42

order of genes matches order of expression (ones for head end at top, tail end at bottom) Also head genes expressed first etc temporal linearity

Question 43

cell cycle regulators- and what they activate

Answer 43

cyclins- they activate cyclin dependent kinases (enzymes) that affect other protiens via phosphorylation.

Question 44

Organisation of homeotic genes

Answer 44

homeotic genes include subset homeobox genes, which invlude subset hox genes

Question 45

Apoptosis

Answer 45

programmed cell death

Question 46

Reasons for apoptosis

Answer 46

- prevent the spread of infection - to de-fuse digits

Question 47

How does apoptosis occur

Answer 47

- signal origionates from within or outside of cell - caspases (protien) break down organelles and cytoskeleton - cell appears shrunken and bulges (BLEBS) appear. - cell is digested by phagocytes

Question 48

what are kinases?

Answer 48

enzymesthat phosphorylate a protien using a phosphate group from ATP