bio things Flashcards
structure of leader sequence
trp 1 stop 2 3 4
where must mutations occur?
in gametes of the person’s parent cell so mutation is passed along to individual and new phenotype arises
genetic screening vs dna profiling
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
reverse transcriptase function
convert mRNA code for ___ into copy DNA so that there are no introns present
function of sgRNA
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
where does CRISPR come from?
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.
why can we produce bacteria that expresses human protein?
because the genetic code is universal, then same amino acids translated from DNA sequences in each organism and so bacteria can express human protein
carbon fixation
C3 plants undergo once, whereas C4 and CAM is more efficient and undergoes it twice to minimise water loss
different in dna in prok + euk
circular vs linear
cytosol vs nucleus
no introns vs introns
function of monoclonal antibodies
Deliver drug in conjugated/loaded form to cancer cell
Activate natural killer cells
Flag cancer cell for phagocytosis by macrophages
Activate complement proteins
advantages of mtDNA
-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
advantages of nuclear DNA
-shows differences BETWEEN species
-large/whole genome (containing genetic info from both parents) so more differences
-greater variation due to mutations, sexual recomb.
if samples of mtDNA taken from living humans is very similar to each other…
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
if the greatest variation of mtDNA is observed within african pops….
the humans first originated in africa b/c greatest time has passed for mtDNA mutation to accumulate over time
african populations=oldest
best wavelengths of light for photosynthesis
red=absorbed most
blue=second most
green light=reflected for absorbed least, why leaves have green colour
advantages of bacteria expressing human protein
-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
what factors can impact rate of movement of DNA fragments in gel electro?
-size or length of fragments
-concentration or viscosity of agarose gel
-voltage or power used
what are biofuels?
liquid or gaseous fuels derived from biomass - plant, animal and algae waste, and is used for transportation
main types of biofuel + production
-bioethanol
-biodiesel
-produced from fermentation of yeast and plants
advantages of gene regulation
-energy is saved
-only certain proteins are needed within a specialised cell
-control quantity of protein producy produced
how are ancient cave drawings rep. of cultural evolution
-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.
reasons for absence of ___ mutation
-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
how does penicillin work?
inhibits cell wall synthesis of bactera
first step in formation of allergy
- sensitisation = humoral immune response producing IgE antibodies upon first exposure to the allergen eg. pollen
key trigger words for humoral response
B cells
antiBodies
Blood (humor)
matures in Bone marrow
extracellular
key trigger words for cell mediaTed response
T cells
Tissue (infecTed)
Tumours
matures in Thymus
inTracellular
what does first dose of vaccination do?
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
why are booster injections necessary?
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
function of T lymphocytes
T cells act on tumours, virally infected cells or foreign tissue
describe two roles of the lymphatic system
-site of clonal selection
-transport system for APCs eg. dendritic cells going to lymph node to initiate clonal selection
function of T memory cells
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.
how do active cytotoxic T cells function
-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
what does a quick increase in the allele frequency of ___ mean?
-there was a strong selection pressure
-there was a strong selective advantage that some organisms had
second step of allergy
- 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)
how does desensitisation work?
produce IgG antibodies = block IgE abs from binding to mast cell and causing allergic symptoms to occur
difference between repeatability and reproducability
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
why is DNA molecule better than protein for determining evo. r/ships
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
what genetic evidence can be used to support out of africa theory?
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
why are there differing views on hominin fam tree?
b/c fossilisation = rare, then interpret small fossils differently + diff conclusions
how to improve experiments
-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
fossil evidence to support divergence
-transitional fossil that is intermediate b/w species
-ancestral fossil w similar structures found at time of divergence
outcome of autoimmune disease?
destruction of tissue by autoantibodies leads to symptoms of the disease
connection between HIV and AIDS
-HIV=retrovirus that infects T helper cells bc carries CD4 receptors
-as immune response weakens over time, eventually AIDS develops (caused by HIV) -> immunodeficiency
antiviral drug functions
-prevent viruses from binding to receptors that allow entry
-inhibit viral enzymes involved in replication
-block transcrip + transl
-prevent from leabing
why is a time frame recommended for a vaccine to be taken before ____?
-to produce more B memory cells
-to allow time for the immune system to produce antibodies
why is antigenic shift more concerning?
bc there might not be any existing adaptive immunity to new antigens
how does natural variation exist b/w indivs of a population?
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.
what does half life mean?
the time taken for half a radioactive element to decay from its parent isotope into into daughter isotope
key=TIME TAKEN
