bio exam preppp vce

Question 1

RESPECT

Answer 1

informed consent

Question 2

integrity

Answer 2

being honest and trustworthy

Question 3

justice

Answer 3

selection of human subjects and non discrimination

Question 4

beneficence

Answer 4

maximising benefit and minimising harm

Question 5

non maleficence

Answer 5

do no harm

Question 6

attenuation

Answer 6

prevents the completion of transcription when trp levels are high and no repressor protein binds onto the operator region
- leader seg to be translated, hairloop pin forms between seg 3 and 4 ribosome detahes stopping transcription
-structural genes not expressed

Question 7

spacers

Answer 7

segments of dna cut from invading viruses allowing bacteria to recognise the same bacteria in the event of another viral infection

Question 8

process of obtaining monoclonal antibodies

Answer 8

antigen is injected into mice so they are induced to produce antibodies to specific antigen
antibodies are isolated and fused with tumour cell to form hybridoma
hybridoma is cultured for monoclonal antibodies
monoclonal antibodies used to target defective cells etc

Question 9

CRISPR CAS9 summary

Answer 9

adaptive immune system of bacteria
virus infects bacteria by injecting its viral dna
spacers sandwiched between the pr and transcribe pre CRrna
crRNA is translated- tracer guide rna
joins w cas 9 endonuclease to cut at a specific recognition site
viral dna disrupted
segment is stored in between spacers.
So. DNA sequence from the bacterial genome transcribed into guide RNA (gRNA).

RNA polymerase uses the DNA sequence as a template to transcribe gRNA with complementary sequence of the spacer and CRISPR segments
The gRNA and cas9 bind form a complex.

It then scans the DNA of any new bacteriophages for the complementary target DNA sequence (to the gRNA).

If present the Cas9 cuts the target DNA.

Question 10

polyploidy

Answer 10

a change in the no of sets of chromosomes (beneficial one)- plants

Question 11

aneuploidy

Answer 11

results when homologous chomosoes fail to segregate in anapahse of meiosis stage 1 or when sis chromatids fail to segragate in anaphase of meiosis stage 2, addition and deletion= detrimental

Question 11

herd immunity

Answer 11

indirect protection of populations from infection. protection is created by vaccinated, unvaccinate receive protection- limits the spread of virus.

Question 11

herd immunity

Answer 11

indirect protection of populations from infection. protection is created by vaccinated, unvaccinate receive protection- limits the spread of virus.

Question 12

ELISA

Answer 12

-antibodies attached to test line
- conjugated antibodies are free to move
-when conjugated antibodies bind onto specific antigen- colour change is observed (think rat tests)

Question 13

steps in allergic response

Answer 13

• allergen
• b cell releases antibodies (iGE)
• iGe attaches itself onto mast cells
  histamines released, immune cells attracted
  allergic reaction ensues.

Question 14

gene regulation trp when high

Answer 14

trp binds onto repressor which allosterically modifies it, binds to operator region preventing the transcription.

Question 15

transcription

Answer 15

-rna polymerase attaches to the promoter region of dna in the upstream region
- unwinds dna exposing the base strand
- rna polymerase moves from upstrem to downstream region (3’ to 5’)
- after rna polymerase moves along dna template, transcription stops and pre-mRNA is released.

Question 16

translation

Answer 16

mrna moves to the ribosome
reads in triplets
each codon corresponds to anticodon found in trna
- trna brings complementary amino acid to ribosome
- builds a pp chain
once reaching a stop (stop codon) , pp is released from ribosome

Question 17

post transcription modifications

Answer 17

introns removed
exons spliced
capping of 5’
addition of poly a tail at the 3’ end

Question 18

vaccine

Answer 18

substance that initiates an immune response

Question 19

control

Answer 19

used to compare results to

Question 20

positive control

Answer 20

associated to what is being tested
(expect it to show the expected results of the experiment being tested on)

Question 21

negative control

Answer 21

is not associated to what is being tested
(expect it to show no results)

Question 22

PCR

Answer 22

denaturation- heated up to denature double strand to single strand
annealing- cooled down and primers bind on either end of dna of interest
extension- taq polymerase begins amplifying dna at either ends of the primer

Question 23

recombinant plasmid

Answer 23

endonuclease cuts plasmid at specific recognition site (sticky ends) same endonuclease is then used to cut dna of interest complementary to the recognition site mixed and joined together via dna ligase (sticky ends)

Question 24

purpose of primers

Answer 24

A primer attaches to complementary DNA nucleotides. The addition of the primer and its joining to complementary nucleotides then allows the DNA polymerase to begin copying. Two primers are needed as the nucleotide sequence is different at the start and finish of the section of DNA that must be copied.

Question 25

physical barrier

Answer 25

physical- intact skin skin microbiome mucus enzymes in tears ear wax nostril hair acid envrionment

Question 26

chemical barrier

Answer 26

sweat mucus tears stomach acid

Question 27

microbiological

Answer 27

flora

Question 28

inflammation

Answer 28

vascular stage- chem signals released attract phagocytes, vasodilation, semipermeable and leaky- swelling cellular stage- phagocyte mugrate to area -consume bacteria and debris resolution stage-platelets move- seal wound, abscess forms

Question 29

structure of antibodies

Answer 29

2 heavy chains, 2 light chains 2 identical specific antigen binding sites

Question 30

action of antibodies

Answer 30

can bind to antigens to stop them functioning opsonisation bind to surface antigens to target them for lysis by complement proteins

Question 31

species

Answer 31

organism that can interbreed to produce fertile offspring

Question 32

why use mtDNA?

Answer 32

inherited from the maternal line non coding region containing d loop region that undergoes mutational changes at a much higher rate than rest of the molecule - track human migration over the world - eacj japlogroup represents diff in mtDNA and allows for the migration of human populations to be tracked out of Africa

Question 33

trp is high

Answer 33

trp will bind to repressor protein, which allosterically modifies it the repressor protein will bind onto the operator region rna polymerase cannot transcribe structural genes genes not expressed