prac exam Flashcards
(56 cards)
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
