questions revise Flashcards
in mitosis, State the structures that will form between the nuclei so that the cell divides into two cells.
cell membrane and cel wall
role of progesterone
maintain lining of uterus
describe role of lh
stimulates ovulation
explain why carbon dioxide is used in galsshouses
carbon dioxide is reactant needed for photosynthesis
increases rate of photosyntehsis
more glucose is produced
co2 is limiting factor outside glasshouse
-more growth of plants/ increased yield
state advantages of biofuels against fossil fuels
renewable resource/ finite
doesn’t cause climate change/ greenhouse gases/ global warming
conserves fossil fuels
produces photosynthesis, thus uses co2
less likely to cause acid rain
what are disadvantages of soil erosion
can cause landslides
reduction of transpiration of plants, can cause floods
desertification
change rainfall pattern
destroys habitats
decreases nutrients available for animals consumption
can cause species extinction
damage growth of plants
what are disadvantages of intensive livestock production
spread of disease quick to wild populations
deforestation for room for livestock
increase in relesion of co2/ greenhouse gases
use of pesticides
use of monoculture to provide food
lack of biodiversity
destruction of habitat
explain how tooth decay happens
-food such as sugar remains in teeth
-bacteria use food, breaks it down into sugars, to use for respiration
-acid is produced
-dissolves enamel
-dentine is exposed, which is soft tissue
describe and explain function of molars
physical digestion
grinds/chews food
increases surface area of food
for amylase action
explain how vasoconstriction reduces heat loss
less heat is lost by radiation or convection by air, less blood flows through surface of skin less heat is lost from blood to surrounding reducing heat lost from organism
outline effects of large scale deforistation on soil
soil erosion, happens, flooidng increases, less absoprtion of water by plants, loss of nutrients in soils, can cause land slides
outline effects of large scale deforistation on rivers
increases water present in rivers, more nutrients present in rivers
explain the importance for the enviornment of developing technologies for recylcing materials such as those found in drink cartons
microplastics can be consumber by aquatic life, plastic is a limted resource, recycling it causes less deforestation, and also uses less energy than making paper.
why were cells immersed in 1.8% salt solution diameter decrease
solution has lower water potential then cells
water moves by osmosis out of the cell unto solution across a partially permeable membrane
from high concentration to low concentration
why was there no change in diameter of red blood cells immersed in 0.9% salt
water potential same in cell and solution
state uses of water in a plant
prevents wilting by providing tugor pressure
translocation
reactant in photosynthesis
as a solvent
describe what is meant by an adaptive feature
inherited feature, makes an organism more adaptable and fit for evniornment it is in, higher chance of survival and reproduction
what is the spongy layer also known as
spongy mesophyll
what adaptation in the spongy mesophyll make hydrophytes fit for enviornment
large and many air spaces, reduces density of leaf, leaf floats on surface of water, makes it more accesible to light, carbon dioxide and gas exchange for photosynthesis
parkinsons disease affects neurones in brain hat are responsible for movement suggest and explain effect of parkinsons disease on a persons movement
movement is slower, slower reflexes, fewer vesicles, fewer neurotransmitters in vesicles, less neurotransmitters released into synaptic clef, fewer diffuse through synaptic clef, fewer bind to receptor proteins
explain how shape of receptor proteins is determined
sequence of bases in gene/ dna determines sequence of amino acids, used to build the protein and determine its shape
what is the role of protein carriers in membranes
carry particles accros partially parmeable membrane during active transport, against concentration gradient, eg. move magnesium ions accross membrane
why is not all oxygen produced in leaf released
some used in respiration and some remains in air spaces
describe role in chlorophyll in photosynthesis
absorbs light, synthesises glucose, converts light energy into chemical energy
describe ways in which the circulatory system of fish is different from circulatory system of a mammal
fish is single circulation, carries blood in lower pressure, one atrium and one ventricle only, only deoxygenated blood pumped by heart
explain advantages of a double circulatory system
prevents mixing of oxygenated and deoxygenated blood ;
blood able to flow at high pressure (to the body) ;
efficient / fast, supply of, blood / glucose / oxygen / nutrients ;
efficient / fast, removal of, waste / carbon dioxide / urea / lactic acid ;
allows efficient filtration in kidneys (for excretion) ;
to allow / maintain, a high, metabolic rate / rate of respiration ;
lower pressure, in pulmonary circuit / to lungs ;
to prevent damage to, delicate tissue / capillaries, in lungs ;
allows more time for gas exchange ;
state ways in which a baby can acquire immunity
vaccination, infection of disease, passive immunity across placenta, injection of antibodies
sepal function
protects flower bud
what does the pollen release during process leading to fertilisation
enzymes, to break down ovary and be able to penetrate ovary
outline advantages and disadvantages of self pollination
ad- more pollination, doesnt rely on pollinators, less pollen produced
dis-less variation, fewer individuals survive, more competition between plants, more succeptable to diseases, less adaptable to changes in enviornment
how is upper epidermis adpated to its function
thin and transparent, allows penetration of sunlight
how is capillary adapted for its function
small lumen
short diffusion distance
slows down blood flow
gaps between cells
thin one cellthick membrane
diffusion of oxygen