movementOM section of struc+func FOR EXAM Flashcards
2.55B plants take in water from the soil through
their root hairs
2.55B root hairs are thinwalled
for a short distance
2.55B root hairs have hair-like extensions to
increase the surface area
2.55B the function of a root hair is to
absorb water and minerals from the soil
2.55B mineral ions are
actively transported into the root hair cells
2.55B water will enter the root hair cell by
osmosis
2.55B the soil water has a … concentration of water molecules
higher
2.55B osmosis is
the net diffusion of water molecules from an area of high water concentration to an area of low water concentration across a partially permeable membrane
2.56B the loss of water vapour from the leaves is called
transpiration
2.56B examiners definition of transpiration
the evaporation of water from the surface of a plant
2.57B how does temperature affect the rate of transpiration
water will evaporate quickly as the water molecules have more kinetic energy
2.57B how does humidity affect the rate of transpiration
humid air - water vapour = smaller conc gradient so transpiration slows down
2.57B how does wind speed affect the rate of transpiration
moving air - water vapour blown away from leaf - speeds up transpiration
2.57B how does light intensity affect the rate of transpiration
in daylight stomata leaves are open to supply CO2 for photosynthesis
allows more water to diffuse out leaves into atmosphere
2.57B transpiration .. as wind speed ..
transpiration increases as wind speed increases
2.57B transpiration .. as humidity ..
transpiration increases as humidity decreases
2.57B transpiration .. as temperature ..
transpiration increase as temp increases
2.57B light intensity does NOT affect
evaporation
2.58B practical: how to set up a potometer
set up underwater
cut the stem
shoot stem in bung
grease joint w jelly (no air entry/water loss)
bung in potometer
tap closed full of water
lift potometer out of water
leave end of capillary tube out of water until air bubble forms & then put in beaker of water
measure rate as distance bubble travelled in 5 mins
2.58B practical: a potometer is to measure
measure the rate of water uptake from a leafy shoot
2.58B practical: we can use potometer to collect readings in normal air or windy conditions by
using a hairdryer on cold
2.58B practical: we can use potometer to collect readings in temperature
increases and decreases
2.58B practical: we can use potometer to collect readings in increased humidity by
using a clear plastic bag
2.58B practical: we can use potometer to collect readings by changing the l & d
lightness and darkness
2.58B practical: changing the environmental factors stimulates
all the different conditions which affect the rate of transpiration
2.71 what are the excretory products of the lungs
carbon dioxide
(via blood plasma)
2.71 what are the excretory products of the kidneys
urea
2.71 what are the excretory products of the skin
urea
2.71 water is lost from the body in the following ways:
via the lungs during exhalation (breathing out)
lost from the skin as sweat (along side mineral ions and urea)
2.72B what does the kidney do
it filters the blood and removes any excess materials and passes them to the bladder to be excreted
2.72B the kidney contains millions of tiny structures called
nephrons
2.72B nephrons are structures which
filter the blood
2.72B what are the 3 main regions of the kidney
cortex, medulla and renal pelvis
2.74B what are the 3 stages that occur in the nephron
ultrafiltration, selective reabsorption and water reabsorption
2.74B the main sections in a nephron
bowman’s capsule
proximal convoluted tubule
loop of henle
distal convoluted tubule
collecting duct
2.74B surrounding the tubule is a network of
capillaries with a knotted section which sits inside the bowman’s capsule
2.74B where does the glomerulus sit
inside the bowmans capsule
2.74B what shape is the bowmans capsule
cup shaped
2.74B the glomerulus is a knot of
capillaries
2.74B where is glucose reabsorbed
in the proximal first convoluted tubule
2.74B the gates that facilitate the active transport of glucose are
only found in the proximal convoluted tubule
2.74B the cells lining in the PCT have many mitochondria to
provide ATP (energy) for active transport
2.74B the cells lining in the PCT have a folded membrane
to increase surface area
2.74B where is water reabsorbed
loop of henle and collecting duct
2.74B where are salts reabsorbed
loop of henle
2.75B step1. the diameter of the efferent arteriole at the exit of the glomerulus is
smaller than the diameter of the afferent arteriole at the entrance causing a build up of pressure
2.75B step1. the build up of pressure in the capillaries forms the
glomerulus
2.75B step2. the pressure causes the smaller molecules being carried in the blood to be forced out of the capillaries and into
the bowman’s capsule
where they form the glomerular filtrate
2.75B step2. small molecules like urea, glucose, amino acids, water and salts are forced
out the glomerulus into the bowmans capsule
2.75B step3. larger molecules like proteins or red blood cells are
too big to fit across the capillary wall so they stay in the blood
2.75B where is water reabsorbed
loop of henle & collecting duct
2.75B where are salts reabsorbed
loop of henle
2.75B where is glucose reabsorbed
proximal first convoluted
2.75B where is urea reabsorbed
it is NOT reabsorbed
2.75B what small molecules are pushed through
urea, glucose, amino acids, water and salts
2.75B what large molecules are too big to go through so stay in the blood
proteins and red blood cells
2.75B what makes up the glomerular filtrate
urea, glucose, amino acids, water and salts
2.77B after the glomerular filtrate enters the bowman’s capsule what’s the first thing to be reabsorbed
glucose is the first substance to be reabsorbed at the proximal (first) convoluted tubule
2.77B selective reabsorption takes place by
active transport
2.77B the cells lining in the PCT have a folded membrane for
an increased surface area
2.77B the cells lining in the PCT have many mitochondria to
provide ATP (energy) for active transport
2.77B reabsorption of glucose cannot take place anywhere else in the nephron as
the gates that facilitate the active transport of glucose are only found in the proximal convoluted tubule
2.77B where does selective reabsorption of glucose occur
in the proximal convoluted tubule
2.77B what’s special about the reabsorption of glucose
its selectively reabsorped
2.79B urine contains
water, urea and ions
2.79B if someone is diabetic their urine may contain
glucose
2.79B urine produced by the kidneys contains a mixture of
urea
excess mineral ions
excess water
2.79B small quantities of urine are usually darker yellow / orange in colour because
it contains little water and so the urea is more concentrated
2.79B large quantities of urine are usually pale yellow in colour
because it contains a lot of water and so the urea is less concentrated
2.79B what produces urine
the kidneys
