prac exam Flashcards
explain why only NPP is available to consumers
respiration wouldn’t go to new trophic levels. NPP is the energy that is stored in new growth.
NPP is GPP- respiration so some would be lost
what is meant by exponential growth
growth rate keeps increasing over time
why would the temperature account for the low NPP of a region
the rate of photosynthesis is reduced and it is a limiting factor
2 ways polar bears are adapted to a carnivorous diet
pointed canines for piercing meat off of bones
sharp incisors on upper and lower jaw for tearing muscle
one enzyme produced by the abomasium and one reason why the contents of the abomasum need to have a low pH
produces pepsin
needs a low pH as is the optimum pH for pepsin (kills bacteria)
describe the process of digestion inside the cell after the formation of the food vacuole
food vacuole fuses with the lysosome, digestive enzymes will be released to digest the food
explain how one structural feature on the small intestine increases the efficiency of protein digestion
intestine is very long
large SA for digestion
3 practical precautions to take to ensure that the offspring produced are only from the desired cross
(F1 generation of a cross)
anthers are removed to prevent self-pollination
pollen is transferred by hand
recipient flower is isolated (e.g. in a bag)
what number do you use if asked to pick the probability of results being significantly different
find what is closest to x2
degrees of freedom
number of groups -1
control of abiotic factors:
same time of year the study is carried out on
so the study is not impacted by other physical factors
e.g temperature
control of abiotic factors
study is carried out at the same time of day
birds/mammals may be active at different times of the day
why might a x10 objective lens not be used
with x10 lens, the magnification is too low
why must a specimen be very flat to be viewed in the microscope
to view the whole depth of the specimen , there are too many layers of cells to let the light through.
advantages of using immobilised enzymes
- can be reused
- only a small quantity of enzyme is needed
- more than one enzyme cane be used, enzymes can be added and removes
what is autotrophic nutrition
producers
they synthesise their own complex organic compounds
example of autotrophic nutrition
plants
simple inorganic compounds (water and carbon dioxide) form complex organic compounds (sugars and starches)
water and co2 to sugar and starches
what is photosynthetic bacteria
use a pigment called bacteriochlorophyll which needs light for photosynthesis
what is chemosynthesis
bacteria that can synthesis organic compounds from inorganic compounds in the absence of light
heterotrophs
cannot synthesise their own organic food. have to consume complex organic food produced by autotrophs .
holozoic feeders
heterotrophic feeders
almost all animals. take food into their bodies and break it down by digestion. (specialised digestive system)
detrivores
feed on dead and decaying animals
saprophytes
feed in decaying matter, feed by secreting enzymes into the food outside the body then absorb the soluble products across the cell membrane by diffusion
parasites
live on or in another living organism and causes harm to the host cell
example of a parasite
tapeworm
mutualism/symbiosis
a close association between members of two different species (both benefit)
example of mutualism
digestion of cellulose in the gut of a herbivore
five tissues in the mammalian gut
-serosa
-longitudinal muscle
-circular muscle
-sub-mucosa
-muscosa
what do glands secrete
some secrete digestive enzymes
what is starch hydrolysed by
amylase forming Maltose
what is maltose hydrolysed by
maltase to form glucose
what happens with glucose
can now be absorbed by the gut (carbohydrate digestion is complete)
what are proteins broken down into
polypeptides, then dipeptides and finally amino acids
what is the protein digesting enzyme called
peptidase
endopeptidases
hydrolyse peptide bonds within the protein molecule to form shorter polypeptides
exopeptidase
hydrolyse peptide bonds at the ends of shorter polypeptides (releasing amino acids)
enzyme found in the mouth
amylase
enzyme in the stomach
hydrochloric acid (pH 2, optimum to kill bacteria)
peptidase enzymes (hydrolysed protein to polypeptides
3
enzyme in the small intestine
lipase (more efficient as lipid droplets have been broken into tiny duplets-higher SA) fatty acids into glycerol
endopeptidase (proteins-peptides)
amylase (starch to maltose)
enzyme in the duodenum
complete digestion
maltase (maltose into two glucose molecules)
endopeptidase and exopeptidase (complete digestion of polypeptides into amino acids)
adaptions of ileum for absorption
very long and the lining is folded to give a larger surface area
finger-like projections called villi (on the folds)
microvilli increase the surface area of the cell membrane of the epithelial cells or absorption
ileum
need to label
muscus secreting goblet cells
blood capillaries and lacteal
crypt of lieberkuhn
circular muscle layer
villus
function of incisors carnivore
sharp to grip and tear muscle from bone
function of canines (carnivore)
large, curved and pointed to tackle prey
function of molars and premolars
Carnivores
sharp points (cusps) to cut and crush
jaw of a carnivore
moves vertically and can open widely
strong muscles
incisors herbivore
on lower jaw only, slices through plants
canines herbivore
indistinguishable from incisors, slice through plants
dental pad
herbivores
leathery pad on upper jaw where food gets pulled across from slicing
premolars/molars
herbivores
p- side teeth for chewing plants
m- interlock, grinding action occurs
jaw
herbivore
lower jaw moves side to side (no strong muscles)
how have parasites become specialised for survival
- suckers and a double row of curved hooks for attachment to the wall of the gut
- body covering- protection from host’s immune system
-both male and female reproductive organs (lots of eggs produced)
describe how the production of amylase was triggered in the barley seeds
when soaked in water, the water enter, gibberellin released to hydrolyse protein. this means that amino acids are released from aleurone layer. these amino acids are then used to make amylase
what do seeds need to germinate
warm temperature
water
oxygen (for respiration)
why is it important that the same concentration of agar and the same concentration of starch were used in all Petri dishes
variables are controlled, results are due to amylase only.
starch is the substrate so it’s important to keep substrate concentrations the same
reason for a decrease in amylase activity after 8 days
leaves appear at day 8
which are able to photosynthesise
so plants can produce it’s own glucose therefore less starch is needed to be broken down
