WRONG ppqs Flashcards
vaccination vs immunisation
vaccination is injection of antigenic material
immmunisation is the porcess of developing immunity
lubdub caused by
LUB = av valves closing
DUB = semilunar valves closing
if the ion is necessary for the function what is it
PROSTHETIC GROUP
in what way does most water move across the root cortex
apoplast pathway
casparian strip contains …
(lignin)SUBERIN
how can facilitated diffusion NOT reqruie energy
- particles have their own kinetic energy
- move DOWN the concentration gradient
why cant glucose diffuse throguh membrane
- phospholipid bilayer acts as a barrier
- glucose molecules too large
- ALSO; glucose not soluble in phospholipid bilayer due to polar -OH groups
suggest how a water leaf is supported
- air spaces give buoyancy
- supoorted by surrounding water
sieve tube shape
hexagonal
purpose of disulfide bridge in antibodies
- hold hte ppcs (light chains and heavy chains) together
what is an autoimmunie disease (2)
- abnormal immune response
- agaisnt tissues normally in the body
how is water stil being lost even when stem is cut in potometer
evaporation
from leaf’s surface
sources of error in transporation experiment
- leaks in apparatus
- shoot not cut underwater
- error in reading position of meniscus
why is x described as ACTIVE immunity (3)
- lymphocytes activated
- antibodies produced
- memory cells remain
why is transpirartion inevtiable
- stomata open
- for gas exchange for photosynthesis
- photosynthesis necessary to make sugars for energy
- water potential gradient
- also some lost through waxy cuticle
advantage of stomata close during day for xerophytes
- transpiration occurs via stomata
- hotter during day, more evaporation. steeper wvp gradient
- shutting prevents loss
advantage of needles instead of leaves for xerophytes
- smaller SA
- less evaporation as fewer stomata
advtantage of hairs on epidermis
- hairs trap water vapour
- prevent wind from removing water vapour
- MORE HUMID AROUND LEAF SO
- reduce WVP gradient
for all xerophyte questions link to…
NEED TO CONSERVE WATER IN ENVIRONMENT
- and wvp gradient
transpiration defintion
- evaporation of water
- diffusion of water
- down a WP gradient via stomata
source and sink defintion
source: where assimilates are loaded into the phloem
sink: where assimilates are removed from phloem
explain how at different times the same plant root might be a source or a sink (2)
SOURCE: when root converts starch into sugars
SINK: when root stores starch
evidence of an active process (translocation)
ATP
many mitochondria in companion cells
against concentration gradient
6 marks for valid potometer set up
- cut healthy shoot underwater -> prevent air entering xylem
- cut shoot at a slant -> increase SA
- apparatus set up under water, full of water -> no air bubblles
- airtight/watertight joints
-dry leaves
3 MARKS - constant conditions
- time for shoot to acclimatise
why is potometer not actual measures of transpiration rate (3)
transpiration: loss of water vapour
- potometer measures water uptake to replace loss
- assumes all uptake is lost
- but some might be used eg photosynthesis
2 features of root hair cell adapted for WATER UPTAKE (3)
- large sa (:v) cos of projection
- thin wall; short diffusion path
- unlignified
3 adaptattions of xylem
- hollow -> ease of flow and more space
- no end walls -> continuous flow
- lignin -> stops collapse, waterproof (spirals)
- narrow lumen -> more capillary rise
why use a large number of x for a mean (2)
- smaller % uncertainty
- results not skewed by anomalies
why would photographing the stomata make them easier to count (2)
- permanent record
- can zoom in
why is x a tissue (2)
- few types of cells
- work together for a specific function
companioin cell adaptations (2)
- living -> active processes
- many mitochondira -> ATP
sieeve tube adaptations (2)
- little cytoplasm -> more space for transport
- sieve plate -> perforations allow materials through
graph question: explain whether x had an impact when it was introduced in x year
- USE DATA FROM GRAPH
- Look at trends that predate the year given
describe the diffusion of x out of the vacuole in NORMAL conditions(3)
- down a concentration gradient (high conc to low conc)
- across TONOPLAST, cell surface membrane
- through cell wall
describe trend (standard deviation increases)
- smallest standard deviation = most precise. largest = least precise+QUOTE DATA
- general trend of precision
ALWAYS ALWAYS LIMITATION OF BENEDICTS
not just glucose- ALL reducing sugars eg fructose
organic molecule defintion (2)
- a molecule containing mainly carbon + other atoms
- eg carbohydrates
why might a tube go cloudy after a NEGATIVE benedicts test (3)
- boiling temp required
- q has denatured
- precipitate produced
why not look at osmosis results IMMEDIATELY (wait 15 mins)
- time for WP to equilibrate
- osmosis may be slow depneding on WP gradient
compare visual vs colorimeter for osmosis
- visual = qualitative
- colorimeter = quantitative
- removes subjectivity
if Rf is v similar to another one, how can you modify the procedure to get a better idea? (2)
- longer chromatography paper
- better resolution
component of blood plasma also present in lymph (2)
- water
- glucose
why might WBC count be high (2)
- patient recovering from an infection
- autoimmune disease
effect of adding dye to a cell
DECREASES water potnetial of cell
how much sugar is detected in the leaf vs the stem?
-LITTLE sucrose in leaf, more in stem
- supports loading of sucrose into phloem from source
how much sugar detected in roots?
-LITTLE sucrose
- shows its used in respiration
how might the antiviral drug prevent the spread of a virus (3)
- something to hinder the viral mRNA
- no viral proteins made
- NO new cells infected
why no plasmolysis in red blood cells (1)
plasmolysis is in plant cells
purpose of UI
- measure end point
purpose of pits in xylem
lateral moevement of water
autoimmune disease
-abnormal immune response
- against tissues normally in body
in waht fluid does the immune response take place
tissue fluid
6 marks improving microscope viewieng (6)
- sharp blade -> thinnest slide, individual cells visisble
- microtome to cut THIN tissue -> thinnest slide, individual cells visible
- wet mount -> prevent dehydration of tissue
how can vesicles be moved around the cell (2)
- attached by cytoskeleton
- moves by MOTOR PROTEINS/mictrotubules change length
2ways to minimise spread of plague (2)
- quarintine those w symptoms
- stay indoors/increase ventilation
disadavtange of RBC no nucleus
- no protein synthesis
- cannot reproduce
why does a plasmodium use a host cell
to ‘hide’ from the immune system
why dont RBC use the oxygen they carry (2)
- bound to haemoglobin
- no mitochondria -> no aerobic respiration
why can overconsuption of x and y lead to malnutrition (4)
- too much energy
- increased fat deposition
- obesity
- lack other food groups
why is glucose used up most quickly before maltose etc
- glucose can be used WITHOUT being broken down
- maltose must be hydrolysed
- ENZYME FOR THAT only made when glucose running out
- takes time for transcription + translation
how to test for pollutatns causing asthma (4)
- use stem cells to grow lung tissue IN VITRO
- subject tissues to atmospheres containing pollutatns
- look for evidence of smooth muscle contracting
mechanism of smooth muscle contracting to constrict airway
- irritant inhaled
- has a shape complementary to the shape of the receptors
- on the plasma membrane of the smooth muscle cells
- they contract
why is oxygen dilevered to insects in gaseous form rather than blood? (7)
- diffusion distance too great to supply enough oxygen for active tissues
- mass flow needed
- insects have an open circulatory system, so movement of blood not as efficient
- diffusin of liquid is slower than that of air
if a complete ring of bark if removes, suggest 2 reasons why the trunk swells above the cut?
- sucrose+assimilates build up above the cut as cant pass
- decrease water potential
- water moves into cells
-increase cell division
- to produce cells to store sugars
method of using length for diffusion
distance has to be divided by 2, to the centre of the cube rather than the whole length
purpose squamous epithelium
short diffusion pathway
purpose loads of alveoli
large surface area
purpose good blood supply + good ventilation
steep concentration gradient
BLOOD SUPPLY: removes oxygen from lungs, VENTILATION: brings oxygen
why is lignin essential (3)
- strengh (support)
- prevents collapse, keeps tube open
- waterproofs vessel so cell dies (contents decays)
- creates a hollow tube, continours column of water
why is cartilage in trachea essential
- strengt/support to keep trachea open, prevents collapse
- during inhaling, volume thorax increases, pressure decreases
substance exhcnage is always to
MEET NEEDS OF ORGANISM
Resolution (2)
- ability to distinguish between 2 points close together
- level of detail
importance of spiral of lignin (2)
- allows flexibility/stretching
- prevents stem breaking
purpose of bordered pits (2)
- allow water to move between vessels
- supply water out to living tissues
adaptations of sieve tube for mas flow
- joined end to end to form column
- sieve plates (perforated end walls)
- little cytoplasm
- no nucleus
descrube active loading (7 MARKS)
- companion cells active transpot H+ ions out
- creates a concentration gradient
- facilitated diffusion back into companion cells. sucrose moves with ions
- by cotransport protein
- assimilates diffuse through PLASMODESMATA
- into sieve element
describe how transpiration contributes to the mechanism of water transport up the stem
- water lost is replaced
- apoplast and symplast pathways
- down WP gradient
- water in the xylem
-loss of water = low hydrostatic pressure at the top - water moves down pressure gradient
- under tension(pulled up)
- by mass flow
- cohesion creates a column of water
- adhesion of water molecules to xylem(capillary action)
why might some flowers survive longer if the ends of the stems are removes before theyre placed in water
- bubble/air present in xylem removed
- restores continous column of water
purpose of repeats (4)
- improve RELIABILITY
- identify anomalies
- calculate mean
-assess spread of results
cohesion tension theory (4)
- evaporation at top of plant
- tension in xylem
- water molecules cohesion
- pulled up the vessel
tranpsiation vs transpiration stream
- : loss of water vapour by evaporation from aerial parts of the leaf, stomata
- stream: movement of water from roots to leaves
porblem if leaves are wet in potometer
- reduces water vapour potential gradient
ar ephospholipids soluble in water
no
waht does cholestrol not contain
glyverol, ester bonds, fatty cids
improve validity
specify somtehing to control
how does an enzyme work (7)
- sibstrate shape complementary to enzyme active site
- substrate binds to active site
- induced fit
- formes ESC
- bonds destabilised
- EPC
- products leave
haemoglobin secondary structure
- alpha helix
- with some smal regions of beta pleated sheet
- held together by h bonds
4 places where h bonds are found in biomols
- protein secondary structure
- protein tertiary structure
- between cellulose chains
- between DNA bases
what are the hpo and hpi interactions (described)
HPO r groups on outside of molecule
HPI r groups on inside of molecule
why does ice float
- moelcules spread out
- lattice
primary defences BLURT (7)
- skin: physcal barrier prevents entry of microorgs. sebum = antibacterial
- mucus membranes: traps pathogens
- cilia: waft mucus out of airways
- blood clot: prevents pathogens entering BLOODSTREAM
- ear wax/nose haris: traps pathogens
- lysozymes in tears: antibacterial to kill bacteria
- stomach acid: kills pathogens
why are young vulnerable
immature weak immune system
anitbody (6 marker blurt)
- y shaped, 4 ppc, 2 light 2 heavy, disulfide bridges
- CONSTANT REGION: opsonin, marker for/binds to phagocytes
- VARIABLE REGION: specific shape, comp to antigen. 1+ VR = agglutination (Attach to 1+ pathogen)
- HINGE: flexibility
- antitoxins, neutralisation
underlying thing for all virsus
- take over host nucleus
- viral DNA inserted into nucleus
- viral mRNA produce
- viral proteins made
why do u need a new vaccine every year
- mutation
- new strain of pathogen
- DIFFERENT ANTIGENS
- og antibody no longer comp
sugest why tb more prevalent in lower income group
- homelessness
- overcrowding
- poor diet
how is tb spread
- droplets containing pathogen
- coughin/sneezing
- inhaled by uninfected individual
how do neutrophils enter tissue fluid
- lobed nucleus
- can change shape
- squeenze through pores in capillary walls
HISTAMINE MAKES WALLS MORE LEAKY
WHY ARE PHAGOCYTES Non specific
can break down a range of diff pathgens
why seconday defence
after pathogen has entered body
why cant bacteria be ‘immune’ (3)
- bacteria dont have an immune system
-theyre resistant - ony multicellular have an immune response
how doe snuetralisation (antibodies- work
- bind to toxins
- preventing entry to host cell
collagen cross links
- covalent bonds formdd between PPC
- staggered to avoid weak points
which of the antibodies bind to gthe antigen
opsonin
agglutinin
why one vax for each pathogen
- diff path diff antigen
- specific shape antibody must be comp to antigen
- diff antibody needed for each pathogen
why are antibody vaxes artifical passive
- injected
- antibodies not produced
agglutinins stop pathogens from
moving and resporducing
casparian strip why does it allow ions in endodermis
- waterproof (doesnt allow water through)
- forces water through apoplast pathway, through PLASMA MEMBRANE
- phospholipid bilayer repels ions so need channel proteins
xylem phloem structure similar
- xylem and SIEVE TUBE ELEMTNS no nuelcues
- both cells joined end to end
improve counting squqares as leaf area (3)
- flatten leaves
- only count squares more than 0.5 covered
- double leaf to give total of both surfaces
water vapour bag method improvmenets
- condensed water reduces trnaspiration. record for shorter time
- temp etc not controlled. so do at the same
if error bars overlap alot
sets of data quite similar
graph (2)
- units
- title
trnaspiartion error (3)
- not all lower leaf covered
- leaks in apparatus
- error in reading position of meniscus
apoplast is between
CELL WALLS
if leaves are diff sizes how to compare transpiration
- calc area
- compare transpiratin per unit area
why might a potometer readin be higher (4)
- bubble not at starting position
- misread rule
- time too long
- light, temp, air movement etc increased
why x apparatus ove the toher
- higher resolution so less uncertainty
POTOMETER ASSUMPTION
water uptake = transpiration
airtight potometer DURING EXPERIMENT
- dont allow bubble to move too far -> so bubble doesnt reenter xylem. can be resued
- submerge end of potometer in water -> prevent air entering
- keep shoot still -> avoid breaking continous water column
hydrophyte adaptations (2)
- many stomata (max ge) and on top surface (gas conc higher in air than water)
- thin waxy cuticle -> waste of wax production
transporting glucose in phloem
CONVERTRED TO SUCROSE
why is sucrose trnasported (2)
- soluble so can be trnasported in sap
- retalively unreactive, not used for respiration during transport
how can u be a source anda sink
- store and release carbs when beeded
- root and leaf, can act as both at diff times of year
disssecting plant stem
- cut a thin cross section using a scalpel
- put sample in water so it doesnt dry out
- stain with TBO (toluidine blue o)
- rinse in water and put on slide
full phloem adaptations
- sieve tube elements living, joined end to end to form sieve tubes
- NO ORGANELLES, LITTLE CYTOPLASM -> max capacity for tranpsorting assimilates
- having no orgs etc means theyre next to a COMPANION CELL, nucleu snad LOTS of mitochondria and ribososmes to produce plasma membrane proteins + energy for active loading
- sieve tube element and cc connected via plasmodesmata -> allows sucrose and assimilates to diffuse from cc into ste
- end of each sieve tube element has a sieve plate. perforations to allow movement of assimilates
sclerenchyma purpose
support to the stem
in the stem the xylem is
ON THE INSIDE
in the root the xylem is
star shaped w the phloem in between
in the leaf teh zylem is
at the top of the vascular bundle
main 3 plant physical defences
- waxy cuticle
- cellulose extra lignified
- callose deposition between cell wal and cell surface memrane
- tallose deposition in the xylem
fish v mammal circulatory blurt 6 marker
SIMILAR
- closed
- heart
- carry o2 w haemoglobin
FISH:
- single
- 2 chambers
- blood passes through TWO sets of capillaries before returning to heart
- lower BP
- so less efficient at syppling o2 to tissues
- but have a lower metabolic rate so is irrelevant
small lumenin artery …
maintains pressure
b;lood clotting
- collagen exposed to blood + air causes clotting response
- cascade of enzymes
- SOLUBLE fibrinogen -> insoluble fibrin
- mesh, traps platelets
- clot prevents bleeding
- DRIES to form a scab
- prevents entry of pathogens
inflammation
- infection by pathogen
- mast cells detect + release histamine
- vasodilation of ARTERIOLEDS, more blood to area and hot
- capillary walls more leaky, more tissue fluid formed -> swelling
- morephagocytess to area for phagocytosis
lymph nodes swelling
after inflaamtion ….
- excess tissue fluid drained to LYMPH VESSELS
- pathogens in TF enter lymph fluid
- transportred in lymph system to lymph nodes
- phagocytosis etc causes swelling of lymph nodes
calibrate graticule and stage micrometer
- put stage micrometer on stage and focus lens
- align eyepeice graticule
- measure how many divisions in sm in 1 epu
why do insect hav e a tracheal system not rely on blood
- EFFICIENCY: diffusion of gases faster than liquids, distance too great to supply enough o2 for active tissues by diffusion etc etc
- OPEN CIRCULATORY SYSTEM-> cannot easily direct blood flow to tissues in need
- blood flow affected by body movements ; transport of o2 unreliable
phagocyte adapttions (6)
- receptors on plasma memvrabe to bind to opsnonin / specfiic antigen
- lobed nucelus -> sqeueze through narrow capillary gaps
- well developed cytoskeleton, CHANGE SHAPE to engulf pathogen+ move around lysosomes
- many lysosomes containing many hyrodolytic enzymes
- many mitochondroa, lors of ar
-many ribosomes to synthesis enzymes
distinguish
monocytes
lymphocytes
neutrophils
in a blood smear
MONOCYTES: bilobed nucleus
NEUTROPHLIS: multi lobed nucleus
LYMPHOCYTES: very large dark nucleus
key word for artificial immunity
INJECTION
action of opsonins (2)
- binds to pathogen AND phagocyte
- increases likelihood of phagocytosis
3 reasons for such rapid MRSA increase
- over use of antibiotics
- fast generation time
- not completing course
Explain why the hydrostatic pressure of the blood drops as blood moves away from the
heart.
- more vessels
- larger total cross sectional area
- reduced resistance to blood flow
exocrine functions of liver
stores bile in gallbladder
if its a lipid based hormone, which molecule does it interact with
DNA (acts as a transcription factor)
why is standard deviation better than using range (2)
- less affected by anomaly
- takes into account all values in the data
why does the cell continue to secrete insulin despite no more glucose being taken in?
- still released as long as blood glucose levels are too high
- ATP still present so k+ channels still closed
- ca2+ channels still open so exocytosis still being caused
homeostasis
- maintenance of a constant internal environment
- within certain limits
- despite a changing environment
consideration when using stain…
use blotting paper to soak up the XS
if non specific immune response is there neutrophils
YES
yeast mecjnaosm of division
budding
cilia are made up of
microtubules
disadvatnage of mean
includes anomalis
anabolic reaction
making larger moleucles from smaller molecules (emdo)
catabolic
breaking down larger molecules to smaller molecules (exo)
calculating a mean improves
reliability
describe induced fit
- substrate binds to AS
- AS shape changes (conformational change)
- closer fit between AS and substrate
- more bonds form between AS sub
- ESC
- Bonds destabilised
- lower activation energy
- EPC
- products released
how isinflammation brought about
- antibody binds to mast cells
- release histamine, causing inflammation
why is mRNA shorter than DNA (2)
- mRNA codes for one gene
- DNA for allllll
parasite (3)
- lives IN host
- takes its nutrition
- harms host
how does plasmodium bypass primary defences (2)
- transmitted by mosquito vector
- pierces the skin
water moves
- osmosis into RHC
- apoplast / asymplast
- across root cortex (epidermis)
respiratory substrate defintion (2)
- broken down
- prpduce ATP
what determines energy of a respiratory substrate
number of c-h bonds
advantage of ATP as energy srouce
- 1 step process (immediate) atp -> adp
Suggest one reason for an RQ greater than 1 in an organism respiring aerobically
carbohydrates converted to lipids
describe SLP
- the phosphate comes from a compound in krebs
- adp + pi = atp
why does facilitated diffusion using carrier protins NOT require energy
- particles have their own KE
- Down concentration gradeitn
describe structure RER
- phospholipid bilayer
- network of flattened sacs (cisternae)
- ribososmes attached on outside
ethanol does what to phospholipid bilayer?
dissolves
how to reduce uncertainty
use more PRECISE equipment
epxlian turgidity
- water enters Vacuole by osmosis
- pushes against cell wall
- turgor pressure
- creating turgid cells
purpose of glycoproteins (4)
- antigens
2.recognition of cells as self or non self
3.cell signalling
4.act as binding site for hormone/drug
cell signalling defintion
cells working otgether
to bring aobut a response
how do LARGE substances go across pplbilayer
- CARRIER proteins
- endocytosis
describe cell signalling (6)
- hormone secreted
- glycoprotein acts as receptor.
- specific chape complementar to that of hormone, so can BIND
- brings about response eg activation of secdonary messenger eg CAMP
role of membranes WITHIN. acell
- selective barrier
- compartmentalisation
- separates contents of org eg hydrolytic enzymes in lysosomes
- creation of concentration gradient
- site for eg attachemnt of enzymes
are there hormones in tissue fluid
yes
3 diff lymph and TF
- lymph less oxygen and nutrients
- lymph more fatty acids
- lymh more WBC
final electron acceptor photosynthesis
nadp
describe how to dissect insect and view
- cut open exoskeleton
- stain tracheoles with METHYLENE BLUE
why is there always residual volume
- trachea held open by cartilage
- surfactant in alveoli
distinguish between lymphocytes and monocytes blood smear
monocyte bigger
monocyte kidney bean shaped nucleus
what do hox genes actually code for
- transcription factors
- which bind to promotor/operator to regulate gene expression
- proteins eg the enzymes for apoptosis coded for
problem with biologucal defintion of species
- doesn taccount for asexual
- phylogenic can be used for extinct species, fossils etc
conservation defintieon (2)
- human intervention
- habitat changed/restored
where is mineral ion balance maintained in kidney
DCT
range of n if greater species evenness
smaller
benefit plant bd on agriculture
- more genetic diversoty
- more likely to survive changing environment eg pathogens
- selective breeding
- pollinators
why do we use the 3 domain system vs 5 kingdom
- differences bewteen bacteria and archaea eg in the cell surface membrane, DNA
- reflects evolutionary history better
- there are fundemental differences between eularyotes and prokaryotes
- eukaryotes all have 80s ribosomes
limiting factor
determines rate at low levels
proof for random error
- large SD
