bio things Flashcards

1
Q

structure of leader sequence

A

trp 1 stop 2 3 4

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2
Q

where must mutations occur?

A

in gametes of the person’s parent cell so mutation is passed along to individual and new phenotype arises

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3
Q

genetic screening vs dna profiling

A

gen screening = testing for certain alleles located in a person’s genome to identify alleles that may lead to disease whereas
dna profiling = separating dna fragments using gel electrophoresis to compare w other ppl for identification purposes

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4
Q

reverse transcriptase function

A

convert mRNA code for ___ into copy DNA so that there are no introns present

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5
Q

function of sgRNA

A

a small section of RNA that guides Cas( to the correct location
is specific and complementary to the target DNA sequence, and is next to a PAM sequence

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6
Q

where does CRISPR come from?

A

CRISPR Cas 9 = primitive adaptive immunity in prokaryotes, where viral DNA from eg. bacteriophages is stored as a guide in the bacterial DNA in sections of CRISpR = spaces.

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7
Q

why can we produce bacteria that expresses human protein?

A

because the genetic code is universal, then same amino acids translated from DNA sequences in each organism and so bacteria can express human protein

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8
Q

carbon fixation

A

C3 plants undergo once, whereas C4 and CAM is more efficient and undergoes it twice to minimise water loss

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9
Q

different in dna in prok + euk

A

circular vs linear
cytosol vs nucleus
no introns vs introns

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10
Q

function of monoclonal antibodies

A

Deliver drug in conjugated/loaded form to cancer cell
Activate natural killer cells
Flag cancer cell for phagocytosis by macrophages
Activate complement proteins

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11
Q

advantages of mtDNA

A

-shows small differences WITHIN a species
-allows tracking of maternal lines of migration
-more available b/c multiple mitochondria in cell
-mutations = only known source of mutations, no sexual recombination
-predictable, known rate of mutations

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12
Q

advantages of nuclear DNA

A

-shows differences BETWEEN species
-large/whole genome (containing genetic info from both parents) so more differences
-greater variation due to mutations, sexual recomb.

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13
Q

if samples of mtDNA taken from living humans is very similar to each other…

A

then modern humans have evolved relatively recently because high similarity in mtDNA and little time for mutations to accumulate

modern humans have evolved from small number of ancestors b/c high similarity

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14
Q

if the greatest variation of mtDNA is observed within african pops….

A

the humans first originated in africa b/c greatest time has passed for mtDNA mutation to accumulate over time

african populations=oldest

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15
Q

best wavelengths of light for photosynthesis

A

red=absorbed most
blue=second most
green light=reflected for absorbed least, why leaves have green colour

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16
Q

advantages of bacteria expressing human protein

A

-constant and reliable supply
-purer or more effective product
-larger quantities produced
-more appealing to patients rather than extracting from animals
-less chance of side effect eg. allergies

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17
Q

what factors can impact rate of movement of DNA fragments in gel electro?

A

-size or length of fragments
-concentration or viscosity of agarose gel
-voltage or power used

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18
Q

what are biofuels?

A

liquid or gaseous fuels derived from biomass - plant, animal and algae waste, and is used for transportation

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19
Q

main types of biofuel + production

A

-bioethanol
-biodiesel

-produced from fermentation of yeast and plants

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20
Q

advantages of gene regulation

A

-energy is saved
-only certain proteins are needed within a specialised cell
-control quantity of protein producy produced

21
Q

how are ancient cave drawings rep. of cultural evolution

A

-cave drawings show passing of information through generations
* cave drawings become more complex over time
* cave drawings show evidence of change in cultural practices
* evidence of complex thought OR evidence of symbolic representations.

22
Q

reasons for absence of ___ mutation

A

-no gene flow between populations w mutations and without
-pop=est. through founder effect, where indivs who broke away did x have mut
-population may not need sel advantage

23
Q

how does penicillin work?

A

inhibits cell wall synthesis of bactera

24
Q

first step in formation of allergy

A
  1. sensitisation = humoral immune response producing IgE antibodies upon first exposure to the allergen eg. pollen
25
Q

key trigger words for humoral response

A

B cells
antiBodies
Blood (humor)
matures in Bone marrow
extracellular

26
Q

key trigger words for cell mediaTed response

A

T cells
Tissue (infecTed)
Tumours
matures in Thymus
inTracellular

27
Q

what does first dose of vaccination do?

A

first dose leads to the activation of B cells and development of a small number of memory cells, and s+c ff abs produced=degrade over time

28
Q

why are booster injections necessary?

A

because memory cells are short lived and degrade over time, then the second dose increases the number of memory cells for a much faster response to subsequent infection and
greater antibody production. therefore, it can rapidly divide into more plasma cells to produce more s+c ff abs in a more rapid response and higher concentration, and more mem b cells

29
Q

function of T lymphocytes

A

T cells act on tumours, virally infected cells or foreign tissue

30
Q

describe two roles of the lymphatic system

A

-site of clonal selection
-transport system for APCs eg. dendritic cells going to lymph node to initiate clonal selection

31
Q

function of T memory cells

A

T memory cells survive for many years have an immediate response - rapidly divide via mitosis into active cytotoxic T cells and T memory cells when the
body is exposed to a pathogen for the second time, mounting a quicker and stronger response.

32
Q

how do active cytotoxic T cells function

A

-moves through tissues checking for antigen displayed on MHC1 marker
-release perforins to cause holes in and damage plasma membrane
-death ligands can stimulate apoptosis

33
Q

what does a quick increase in the allele frequency of ___ mean?

A

-there was a strong selection pressure
-there was a strong selective advantage that some organisms had

34
Q

second step of allergy

A
  1. degranulation = upon secondary exposure to the allergen, cross links form b/w IgE abs attached to mast cell and allergen, causing excessive histamine release via exocytosis. this causes exagg inflammation, excessive mucous prod. and smooth muscle contractions (wheezing)
35
Q

how does desensitisation work?

A

produce IgG antibodies = block IgE abs from binding to mast cell and causing allergic symptoms to occur

36
Q

difference between repeatability and reproducability

A

repeat=same procedure, can be carried out by diff people testing for same thing under same conditions and same procedure

reprod=diff procedure, obtaining same or similar results and testing same thing but w different method

37
Q

why is DNA molecule better than protein for determining evo. r/ships

A

bc DNA = degenerate w multiple codons coding for the same amino acids, then X always tell when silent mutations have occurred. t/f also show 3 times more info

38
Q

what genetic evidence can be used to support out of africa theory?

A

1-mut accumulate over time, modern african pop. have greatest no of mtDNA mutations so originated from african h descent and moved out

2-modern humans x of african descent share 1-4% of DNA w Neanderthals as they interbred after moving out of Africa

39
Q

why are there differing views on hominin fam tree?

A

b/c fossilisation = rare, then interpret small fossils differently + diff conclusions

40
Q

how to improve experiments

A

-repeat more than 5 times
-improve measuring tool of DV to improve accuracy
-higher range of values for IV
-control pH and temp
-add control group for comparison to normal reaction

41
Q

fossil evidence to support divergence

A

-transitional fossil that is intermediate b/w species
-ancestral fossil w similar structures found at time of divergence

42
Q

outcome of autoimmune disease?

A

destruction of tissue by autoantibodies leads to symptoms of the disease

43
Q

connection between HIV and AIDS

A

-HIV=retrovirus that infects T helper cells bc carries CD4 receptors
-as immune response weakens over time, eventually AIDS develops (caused by HIV) -> immunodeficiency

44
Q

antiviral drug functions

A

-prevent viruses from binding to receptors that allow entry
-inhibit viral enzymes involved in replication
-block transcrip + transl
-prevent from leabing

45
Q

why is a time frame recommended for a vaccine to be taken before ____?

A

-to produce more B memory cells
-to allow time for the immune system to produce antibodies

46
Q

why is antigenic shift more concerning?

A

bc there might not be any existing adaptive immunity to new antigens

47
Q

how does natural variation exist b/w indivs of a population?

A

Natural variation exists in a population through mutations that may have created new alleles or by
different allele combinations in sexual reproduction (sexual recombo)
Changes in chromosome number may change phenotype.

48
Q

what does half life mean?

A

the time taken for half a radioactive element to decay from its parent isotope into into daughter isotope
key=TIME TAKEN