Past paper stuff Flashcards
what is yeast means of cell division
budding
what is bacterium means of cell division
binary fission
does yeast have a nucleus ?
yes
what is the material in cell wall of bacterium ?
peptidoglycan
are ribosomes present in plants and yeast ?
yes
name two types of cells found in phloem
- companion cell
- sieve element
why do single celled organisms not need specialized gas exchange systems ?
very small organism with large SA:Vol ratio, so diffusion pathway is short
what is the process of expelling substances from cells called ?
exocytosis
state function of smooth muscle in lungs
constrict / reduce diameter of airways
why must cells be stained ?
to increase contrast and make cells visible
describe the roles of cytoskeleton
- supports cell
- moves cilia / flagella
- exo / endocytosis
- moves organelles
name one organelle structure present in animals and not in plants
centriole
describe how hydrogen carbonate ions are produced in erythrocytes
- CO2 diffuses into RBC and combines with water
- with carbonic anhydrase enzyme, carbonic acid is produced
- this dissociates into H+ and HCO3 - ions
how does Bohr shift reduce amount of oxygen transported ?
- reduces affinity for oxygen
- CO2 alters shape of haemoglobin
in vascular bundle, which is on top / bottom ?
top - xylem
bottom - phloem
what is ultra structure ?
the detailed structure of cells that is visible only with an electron microscope
how are guard cells adapted for their role
- unevenly thickened cell wall
- able to change shape
what to remember to mention with xylem walls ?
lignin and pits
what tissue has cilia ?
ciliated
how are alveoli adapted ?
- elastic (recoil) which helps ventilation
- large no. of them (high SA)
- surfactant
- 1 cell thick (squamous)
what does surfactant do in lungs ?
reduces surface tension of fluid and makes alveoli more stable (prevents collapsing)
why must fetal haemoglobin have high affinity for oxygen ?
must be able to bind to oxygen at low partial pressure
what to remember with enzyme / substrate ?
- active site
- induced fit
what to remember when describing enzyme graphs ?
- collisions w/ active site
- Vmax
what word to use when describing enzyme in high pH
denature
what are the bonds in cellulose ?
beta 1-4 glycosidic bond
why is lock + key / induced fit described as models ?
it is a representation of the process
why is induced fit now more accepted that lock + key ?
supported by more evidence
describe translation in 5 steps
- mRNA moves to ribosome
- tRNA has anticodon complementary to codon
- tRNA anticodon binds to mRNA codon
- specific amino acid attaches to tRNA
- repeat with rRNA catalysing peptide bond formation between amino acids
a gene is a section of DNA that codes for the production of a …
polypeptide
state how glucose is suited for its function :
- soluble (transport)
- easily broken down to release energy
- small (transport between membranes)
where are glyco lipids/proteins situated with membrane ?
sticking out of the membrane
state three functions of membranes of membranes within cells
- separate contents from cytoplasm
- form vesicle / organelle
- site for enzyme attachment
what does cholesterol do to cell membrane ?
stabilize
what is the model of the cell membrane called ?
fluid mosaic
describe route water takes through cell membranes
- channel proteins
- passes between lipids
two things you can do to make experiment more reliable …
- calculate a MEAN
- identify anomalous results
state the order of the cardiac myogenic muscle cycle
SAN – R&L atria contract – AVN – bundle of His – Purkyne tissue – R&L ventricles contract
what is the haemoglobin equation ?
Hb + 4O2 – HbO8
why are phagocytes described as secondary defense ?
defense after pathogen has entered body
why are phagocytes considered non specific ?
target a range of different pathogens
why must influenza vaccine change every year ?
- different strains of the pathogen mutate
- antigens change
- antibodies have no effect on changed antigen
why are antibiotics not used on viruses ?
not effective on viruses (only effective on bacteria)
define transpiration
loss of water VAPOUR from leaves
define transpiration stream
movement of water from roots to leaves
what is systole ?
contraction
what is diastole ?
relaxation
why does pressure decrease between blood vessels ?
- lumen size increases
- no. of vessels increases
what stain for TEM ?
heavy metal
what stain for SEM ?
reflective metal
“pumped” is an expression for what ?
active transport
“pumps” are …
carrier proteins
what is pinocytosis ?
cell taking in liquid by “endocytosis”
what are the two ways to xylem from roots ?
- apoplast (through cell walls)
- symplast (through cytoplasm + plasmodesmata)
what forces water into symplast ?
casparian strip (at the endodermis)
what substance does casparian strip contain ?
suberin (waterproof so water forced into cytoplasm)
how does water leave the leaf ?
water vapor diffuses out
what is ficks law ?
(SA x difference in conc) / thickness of membrane
define parasite
- lives in host
- feeds from host
- harms host
simply describe budding
- vesicle forms on surface of cell
- organelles + chromosomes duplicate (mitosis)
- organelles … move to bud
- bud pinches off
how is plasmodium spread ? what cell does it latch on to ?
mosquito / erythrocytes
what to remember when describing antibody structure ?
light / heavy chains
how do antibodies “neutralise” pathogens
- cover binding site
- bind to toxins
- prevent binding to host cell
how can phagocytes pass through capillary walls ?
- histamines make leaky
- lobed nucleus allows change in shape
how is TB spread ?
droplets
name the infective agent that cases TB
mycobacterium
what causes low income to have higher disease ?
- overcrowded
- poor ventilation
- poor diet
- less treatment available
give function of phospholipid bi layer
act as barrier
define cell signalling
communication between cells to trigger a response
when drawing chromosomes… remember …
to draw centro meres
state function of elastic fibers in alveoli
stretch + recoil to force air out
what to remember when describing inspiration / expiration …
below / above atmospheric pressure
THORAX vol / pressure
what is the role of Atrioventricular node ?
delays impulse + sends impulse down to bundle of His
describe features of artery walls …
- no valves
- endothelium folded
- elastic tissue
- smooth muscle
why is lignin needed ?
- strengthen
- keep tube open
- waterproof
describe the term resolution
closest 2 points can be and be distinguished as separate, giving clarity of image, so can see detail
why lignin structured in a spiral ?
allows for flexibility
give function of pits in xylem
- allows water to move between vessels
- supply water to cells / tissues
water moves through which way most… apoplast / symplast ?
apoplast
name the co factor for amylase
chloride
name the co factor for carbonic anhydrase
zinc ions
why is their residual volume ?
- thorax cannot be fully compressed
- trachea have cartilage
what type of variation occurs at metaphase 1 ?
independent assortment of homologous chromosomes
what type of variation occurs at metaphase 2 ?
independent assortment of chromatids
what type of variation occurs at prophase 1 ?
crossing over between chromatids
how does crossing over create variation ?
genetic material is swapped, giving a new combination of alleles
how do gametes give variation ?
diff gametes with diff genetic makeup fuse
what type of fatty acid do animals have ?
saturated - solid
what type of fatty acid do plants have ?
unsaturated - liquid
name the three tunicas
intima / intermediate / adventitia
give the two functions of lignin
- strengthen cell wall
- waterproofing
what to remember for resolution definition…
gives detail
what are the pits for in the xylem?
allows water to pass through
suggest two processes inside cells that rely on cytoskeleton
- cytokinesis
- movement of RNA
how do things move by the cytoskeleton ?
- move along micro filaments/tubules
- uses ATP
Explain fetal haemoglobin (4)
- higher affinity for O2
- takes up O2 at lower pO2
- placenta has low pO2
- haem dissociates in placenta
name two medical conditions linked with obesity
- type 2 diabetes
- coronary heart disease
what to say instead of signal when talking about the heart
impulse
what is diastole ?
relaxation
what is systole ?
contraction
specify the collisions when talking about enzymes
collisions w/ active site
when talking about neurotransmitters travelling, what word must use ?
diffuse
state reasons for importance of synapses
- ensures impulses travels one direction
- allows summation
- integration
- permits learning / memory
- filters out low level stimuli
what word to use instead of broken down ??
HYDROLYSE
outline process of how enzyme breaks down substrate
- sub binds to compl. shape of active site
- induced fit
- enzyme complex forms
- enzymes puts strain on bonds
- enzyme product forms
- product leaves active site
what shape are globular / fibrous ?
globular - spherical
fibrous - linear
what does low Simpson’s index of diversity show ?
- dominant species
- habitat unstable
what is phylogeny and how is it related to classification ?
- relationship between history of organisms
- basis of classification
what is function of recognition region in antibody ?
allows for recognition for phagocytes
what does an antibody bind to ?
pathogen antigen
how do antibodies neutralise toxins ?
- block binding site on pathogen
- binds to toxins
- prevents pathogen from binding to host cells
state 5 specific roles that sympathetic and parasympathetic oppose
heart rate / breathing rate / airways diameter / pupil diameter / peristalsis
where are hormones produced in mammals / plants ?
endocrine glands / plant tissues
other than chemiosmosis, what is the process that produces ATP?
substrate level phosphorylation (removing phosphate from a compound)
how to spell diafram
diaphragm
endocrine secretes ..
into blood
exocrine secretes …
into ducts that lead to target tissues
pluripotent stem cells are …
embryo stem cells (can differentiate to any)
multipotent stem cells are …
adult stem cells (can differentiate to some)
define sister chromatid
identical copies of the same chromosome
