|
Hint
|
|
Answer
|
|
light dependent reaction: (1) a pair of electrons in ____ absorb light energy
|
|
chlorophyll
|
|
(2) they leave the molecule (____)
|
|
photoionisation
|
|
(3) they are passed along the ____ which is a series of protein carriers in the thylakoid membrane
|
|
electron transfer chain
|
|
(4) the electrons lose energy at each stage, some of which is conserved in production of ____
|
|
ATP
|
|
(5) ____ of water replenishes the chlorophyll electrons - also produces protons and oxygen
|
|
photolysis
|
|
(6) protons pass out of the thylakoid space and they, along with the electron pair, reduce ____
|
|
NADP
|
|
the oxygen is a ____ and diffuses out of the leaf or can be used in respiration
|
|
byproduct
|
|
ATP is produced by ____ theory
|
|
chemiosmotic
|
|
(1) protons are pumped from the ____ to the thylakoid space
|
|
stroma
|
|
(2) this creates a concentration gradient of protons which can only pass out of the thylakoid space through ____ channel proteins
|
|
ATP synthase
|
|
(3) as the protons pass through, they change the protein's shape and allow it to catalyst formation of ____
|
|
ATP
|
|
light independent reaction: (1) carbon dioxide reacts with ____
|
|
ribulose bisphosphate
|
|
to produce 2 molecules of ____
|
|
glycerate-3-phosphate
|
|
which is catalysed by ____
|
|
rubisco
|
|
(2) ATP and ____ are used to reduce GP
|
|
NADP
|
|
to ____
|
|
triose phosphate
|
|
(3) some of this is used to regenerate RuBP in the ____ and some is converted to useful organic products
|
|
Calvin cycle
|
|
factors that affect ____ include: temperature, light intensity, carbon dioxide concentration
|
|
photosynthesis
|
|
respiration stage one: ____
|
|
glycolysis
|
|
occurs in the ____ and is anaerobic
|
|
cytoplasm
|
|
(1) glucose is phosphorylated to ____ using ATP
|
|
glucose phosphate
|
|
(2) which is converted to ____
|
|
triose phosphate
|
|
(3) which is oxidised to ____
|
|
pyruvate
|
|
there is a net gain of ATP and ____
|
|
reduced NAD
|
|
if respiration is only ____, pyruvate can be converted to ethanol or lactate using reduced NAD
|
|
anaerobic
|
|
the oxidised NAD produced in this way can be used in further ____
|
|
glycolysis
|
|
if respiration is aerobic, pyruvate enters the ____ by active transport
|
|
mitochondrial matrix
|
|
stage two: ____
|
|
link reaction
|
|
(1) pyruvate is oxidised to ____, producing reduced NAD
|
|
acetate
|
|
(2) acetate combines with ____ to produce acetyl coenzyme A
|
|
coenzyme A
|
|
stage three: ____
|
|
Kreb's cycle
|
|
(1) acetyl coA reacts with a ____C molecule, releasing coA and producing a 6C molecule
|
|
4
|
|
(2) in a series of redox reactions, the Krebs cycle generates reduced coenzymes NAD and ____
|
|
FAD
|
|
and ATP by ____
|
|
substrate level phosphorylation
|
|
synthesis of ATP by ____ is associated with transfer of electrons down the ETC and chemiosmotic theory across the inner mitochondrial membranes
|
|
oxidative phosphorylation
|
|
plants synthesis organic compounds from ____
|
|
carbon dioxide
|
|
most of the sugars synthesised are used as ____ substrates and the rest to form other biological molecules
|
|
respiratory
|
|
biological molecules form the ____ which is mass of carbon or dry tissue per given area
|
|
biomass
|
|
the chemical energy store in dry biomass can be estimated using ____
|
|
calorimetry
|
|
chemical energy store in plant biomass in a given area or volume
|
|
gross primary production
|
|
chemical energy store in plant biomass after respiratory losses to the environment have been taken into account
|
|
net primary production
|
|
NPP is available for plant growth and reproduction and to other ____ levels in the ecosystem
|
|
trophic
|
|
net production of ____ = chemical energy store in ingested food – (chemical energy lost to the environment in faeces and urine + respiratory losses to the environment)
|
|
consumers
|
|
the synthesis of organic molecules from inorganic sources, primarily by plants and algae through photosynthesis (biomass per area per time)
|
|
primary productivity
|
|
the creation of new biomass by consumers (biomass per area per time)
|
|
secondary productivity
|
|
increasing productivity while farming ____: restrict movement, warm environment to reduce heat loss, control feeding to minimise wastage and maximise growth, exclude predators
|
|
animals
|
|
increasing productivity while farming ____: simplify food webs, pest control to minimise effects of pests (especially important in monocultures)
|
|
plants/crops
|
|
nitrogen cycle: plants take up ____ ions from their roots and animals by ingesting plants
|
|
nitrate
|
|
nitrate ions are soluble and ____ through the soil
|
|
leach
|
|
naturally, nitrate concentrations are largely restored by recycling nitrogen containing compounds but can use ____ agriculturally
|
|
fertilisers
|
|
where ammonia is produced from organic nitrogen-containing compounds
|
|
ammonification
|
|
this occurs when ____ feed on dead organisms and break down their polypeptides e.g.
|
|
saprobionts
|
|
oxidation of ammonium to nitrite to nitrate by nitrifying bacteria
|
|
nitrification
|
|
____ process so to raise productivity, farmers keep soil aerated by ploughing and employ good drainage to prevent air spaces filling with water
|
|
aerobic
|
|
converting atmospheric nitrogen ____ to nitrogen containing compounds
|
|
gas
|
|
can be done by free living or ____ bacteria (which live in root nodules on legumulous plants)
|
|
mutualistic
|
|
anaerobic denitrifying bacteria convert soil nitrates into gaseous nitrogen
|
|
denitrification
|
|
symbiotic relationships between fungi and plant roots
|
|
mycorrhizae
|
|
fungae form long thin ____ that connect with plant roots and increase surface area of the root system, benefitting the plant by increasing absorption of water and inorganic ions
|
|
hyphae
|
|
in return the fungi receive ____ compounds
|
|
organic/carbon
|
|
natural ( ____ ) fertilisers consists of the dead and decaying remains of plants and animals and their wastes
|
|
organic
|
|
artificial ( ____ ) fertilisers are mined from rocks and deposits then converted into different forms and blended to give the right balance for a particular crop
|
|
inorganic
|
|
using nitrogen containing fertilisers can impact the environment: (1) reduced species ____ because nitrogen-rich soils favour fast-growing species
|
|
diversity
|
|
(2) ____ can cause nitrate ions to enter water sources. high nitrate concentration can prevent efficient oxygen transport in babies
|
|
leaching
|
|
(3) ____ where nitrate ions cease to be a limiting factor for plant and algal growth
|
|
eutrophication
|
|
causes ____ which absorbs light and prevents it penetrating to lower levels
|
|
algal bloom
|
|
the plants and algae below can no longer ____ and die
|
|
photosynthesis
|
|
concentration of oxygen in the water is reduced and ____ organisms die
|
|
aerobic
|
|
____ organisms have less competition and populations rise
|
|
anaerobic
|
|
these decompose dead material, releasing more nitrates and some toxic wastes like ____ which putrifies the water
|
|
hydrogen sulfide
|
|
in flowering plants, specific growth factors move from growing regions to other tissues where they regulate growth in response to ____ stimuli
|
|
directional
|
|
IAA ( ____ ) controls plant cell elongation and is an auxin
|
|
indoleacetic acid
|
|
____ is where plants grow in response to light
|
|
phototropism
|
|
(1) cells in the ____ tip produce IAA which is initially transported evenly throughout all regions as it moves down the ____
|
|
shoot
|
|
(2) ____ causes movement of IAA from the light side to the shaded side
|
|
light
|
|
(3) a greater ____ of IAA builds up on the shaded side
|
|
concentration
|
|
(4) IAA causes ____ of shoot cells so the cells on the shaded side elongate more
|
|
elongation
|
|
this causes the shoot tip to bend ____ the light
|
|
towards
|
|
____ is where plants grow in response to gravity
|
|
gravitropism
|
|
(1) cells in the ____ tip produce IAA which is initially transported evenly along the ____
|
|
root
|
|
(2) a greater concentration of IAA builds up on the ____ side of the root
|
|
lower
|
|
(3) IAA ____ elongation of root cells so the cells on the lower side elongate less
|
|
inhibits
|
|
(4) the root bends downwards towards the force of ____
|
|
gravity
|
|
a simple response whose direction is determined by the direction of the stimulus
|
|
taxis
|
|
moving towards a favourable stimulus
|
|
positive taxis
|
|
moving away from an unfavourable stimulus
|
|
negative taxis
|
|
an organism changes the speed at which it moves and the rate at which it changes direction
|
|
kinesis
|
|
rate of turning ____ as an organism moves into an unfavourable environment, raising chances of returning quickly to a favourable one
|
|
increases
|
|
as they get further into the unfavourable environment, rate of turning may ____ so that it moves in long straight lines before turning sharply
|
|
decrease
|
|
kinesis is important where a stimulus is not as ____
|
|
directional
|
|
____ arc: stimulus, receptor, sensory neurone, intermediate neurone, motor neurone, effector, response
|
|
reflex
|
|
stimulation of a receptor by specific stimuli leads to establishment of a ____
|
|
generator potential
|
|
the ____ responds to pressure and occurs deep in the skin
|
|
Pacinian corpuscle
|
|
the single ____ of a Pacinian corpuscle is at the centre of layers of connective tissue separated by gel
|
|
sensory neurone
|
|
a ____ surrounds the layers and there is a blood capillary in the ____
|
|
capsule
|
|
when pressure is applied, the PC is deformed, the membrane around the neurone is widened, and the ____ open
|
|
stretch mediated sodium ion channels
|
|
this ____ the membrane and produces a generator potential
|
|
depolarises
|
|
this in turn creates an ____
|
|
action potential
|
|
the light receptor cells in a mammalian eye are found in the ____
|
|
retina
|
|
rod cells: (1) cannot distinguish different ____ of light
|
|
wavelengths
|
|
(2) more numerous than ____
|
|
cone cells
|
|
(3) many rod cells are connected to a single sensory neurone in the ____
|
|
optic nerve
|
|
(4) used to detect low ____ light
|
|
intensity
|
|
(5) many rod cells are connected to a single ____ cell
|
|
bipolar
|
|
this is ____ and gives a greater change the threshold value will be exceeded than if only one rod cell were connected
|
|
retinal convergence
|
|
this uses ____
|
|
spatial summation
|
|
(6) a certain ____ has to be exceeded before a generator can be created
|
|
threshold value
|
|
(7) in order to create a generator potential, the ____ pigment in the rod cells must be broken down
|
|
rhodopsin
|
|
low ____ light is enough to break this down
|
|
intensity
|
|
the light received by rod cells sharing the same ____ will only generate one impulse
|
|
neurone
|
|
this means rod cells give low ____ as the brain cannot distinguish separate sources of light that stimulated them
|
|
visual acuity
|
|
mostly found at the peripheries of the ____ where light intensity is low
|
|
retina
|
|
____ cells are of three types, each responding to a different range of wavelengths of light
|
|
cone
|
|
(1) they often have their own bipolar cell so ____ cannot be used to exceed the threshold but have good visual acuity
|
|
summation
|
|
so they only respond to high light ____
|
|
intensity
|
|
(2) they contain ____ pigment which requires high intensity light to break down
|
|
iodopsin
|
|
(3) they are found mostly at the ____ (where light is focussed by the lens)
|
|
fovea
|
|
the heart muscle is ____ - contraction is initiated from within the muscle
|
|
myogenic
|
|
process: (1) a wave of electrical excitation spreads out from the ____ in the right atrium wall
|
|
sinoatrial node
|
|
this spreads across both atria and causes them to ____
|
|
contract
|
|
the ____ is non-conductive and prevents the wave crossing to the ventricles
|
|
atrioventricular septum
|
|
(2) the wave enters the ____ which lies between the atria and there is a short delay to allow the atria to empty
|
|
atrioventricular node
|
|
(3) the AVN conveys the wave along the ____ tissue (which collectively makes up (4))
|
|
Purkyne
|
|
(4) the ____ conducts the wave through the atrioventricular septum to the base of the ventricles
|
|
bundle of His
|
|
(5) the wave of excitation is released from the Purkyne tissue, causing the ____ to contract
|
|
ventricles
|
|
changes to heart rate are controlled by the ____ which has a centre for increasing heart rate and one for decreasing it
|
|
medulla oblongata
|
|
____ are sensitive to blood pH changes and are found in the wall of the carotid arteries
|
|
chemoreceptors
|
|
pressure receptors occur within the walls of the carotid arteries and the ____
|
|
aorta
|
|
low pH or low pressure cause an increase in ____ of impulses from these receptors to the medulla
|
|
frequency
|
|
along the ____ pathway
|
|
sympathetic
|
|
so the medulla increases frequency of impulses to the ____ and thus increases heart rate
|
|
sinoatrial node
|
|
high pH or high pressure transmit impulses along the ____ nervous system pathway to reduce heart rate
|
|
parasympathetic
|
|
uses nerve cells to pass electrical impulses along their length, and stimulate target cells by releasing neurotransmitters. rapid, short-lived, localised response
|
|
nervous system
|
|
glands produce hormones that are transported in the blood and stimulate receptors on target cell membranes. slower, longer-lasting, more widespread
|
|
hormonal system
|
|
a ____ motor neurone has the following structure:
|
|
myelinated
|
|
(1) cell body containing cell organelles including large amounts of ____ to produce neurotransmitters
|
|
rough endoplasmic reticulum
|
|
(2) ____ : extensions of the cell body that subdivide into dendrites and carry impulses towards the cell body
|
|
dendrons
|
|
(3) a single long fibre that carries nerve impulses away from the cell body
|
|
axon
|
|
(4) ____ cells which surround the axon, protect, insulate, carry out phagocytosis on debris, help nerve regeneration
|
|
Schwann
|
|
their membranes wrap around the axon and layers build up and form the ____
|
|
myelin sheath
|
|
(5) ____, where there are constrictions between adjacent Schwann cells with no myelin sheath
|
|
nodes of Ranvier
|
|
____ is maintained in the axon by actively transporting out sodium ions at a greater rate than actively transporting in portassium ions
|
|
resting potential
|
|
resting potential is ____ mV in humans
|
|
-65
|
|
here the axon is said to be ____
|
|
polarised
|
|
(1) the energy of a stimulus arriving causes some voltage-gated ____ ion channels to open
|
|
sodium
|
|
(2) sodium ions diffuse into the axon along their ____ gradient
|
|
electrochemical
|
|
(3) ____ feedback causes more sodium ion channels to open
|
|
positive
|
|
(4) they trigger ____ of the axon
|
|
depolarisation
|
|
(5) the threshold potential of about ____ mV is established
|
|
+40
|
|
(6) the voltage gated sodium ion channels close and the voltage gated ____ ion channels open
|
|
potassium
|
|
(7) potassium ions diffuse out, starting ____ of the axon
|
|
repolarisation
|
|
(8) this causes temporary ____
|
|
hyperpolarisation
|
|
(9) the potassium ion channels close and once again ____ potential is established
|
|
resting
|
|
along an ____ axon, this is how the action potential moves along the axon:
|
|
unmyelinated
|
|
(1) the membrane is ____ at one point
|
|
depolarised
|
|
(2) the localised ____ currents cause opening of sodium ion channels further along, causing depolarisation
|
|
electrical
|
|
(3) behind this new region of depolarisation, ____ occurs
|
|
repolarisation
|
|
(4) the action potential is ____ along the axon
|
|
propagated
|
|
along a ____ axon, the myelin sheath acts as an electrical insulator
|
|
myelinated
|
|
the localised circuits jump between adjacent nodes of Ranvier - ____ conduction
|
|
saltatory
|
|
a larger ____ of an axon leads to faster conduction due to less leakage of ions
|
|
diameter
|
|
higher temperatures can increase rate of diffuse of ions up to the point that relevant ____ denature
|
|
enzymes
|
|
all ____ potentials are the same size
|
|
action
|
|
the individual can tell the size of a stimulus through ____ of impulses in a given time and by having neurones with different threshold values
|
|
frequency
|
|
the period where inward movement of sodium ions is prevented because the sodium voltage gated channels are closed
|
|
refractory period
|
|
three purposes of this: (1) ensures action potentials are only ____ in one direction
|
|
propagated
|
|
(2) produces ____ impulses
|
|
discrete
|
|
(3) limits the number of action potentials in a given time so the strength of ____ that can be detected
|
|
stimulus
|
|
synapses are ____ (impulses only travel one way)
|
|
unidirectional
|
|
summation where many neurones give an impulse
|
|
spatial
|
|
summation where one neurone gives many impulses in a short time
|
|
temporal
|
|
synapses that make it less likely a new action potential will be created on the postsynaptic neurone
|
|
inhibitory
|
|
(1) the presynaptic neurone releases neurotransmitter that binds to ____ channels on the postsynaptic neurone
|
|
chloride ion
|
|
(2) chloride ions move into the postsynaptic neurone by ____
|
|
facilitated diffusion
|
|
(3) the binding of the neurotransmitter causes ____ ion channels to open and ____ ions to diffuse into the synapse
|
|
potassium
|
|
(4) this makes the membrane potential more negative ( ____ )
|
|
hyperpolarisation
|
|
(5) this makes it less likely a new action potential will be created because a larger influx of ____ ions will be required
|
|
sodium
|
|
____ are stimulated to contract by nerves and act as effectors. they act in antagonistic pairs against an incompressible skeleton
|
|
skeletal muscles
|
|
made up of muscle fibres called ____
|
|
myofibrils
|
|
these share nuclei and cytoplasm (called ____ ) which is found at the circumference of the fibre and contains a large concentration of mitochondria and endoplasmic reticulum
|
|
sarcoplasm
|
|
myofibrils are made up of (1) ____ which is thinner and consists of two strands twisted around one another
|
|
actin
|
|
(2) ____ which is thicker and consists of long, rod-shaped tails with bulbous heads that project to the side
|
|
myosin
|
|
light bands in myofibrils: ____ bands, thick and thin filaments do not overlap, thin filaments only
|
|
I
|
|
dark bands: ____ bands, thick and thin filaments do overlap
|
|
A
|
|
lighter region at the centre of each A band, thick filaments only: ____ zone
|
|
H
|
|
at the centre of each I band is the ____ line
|
|
Z
|
|
the distance between adjacent Z lines is called a ____
|
|
sarcomere
|
|
the point where a motor neurone meets a skeletal muscle fibre
|
|
neuromuscular junction
|
|
all muscle fibres supplied by a single motor neurone
|
|
motor unit
|
|
when a nerve impulse is received, ____ ions diffuse in and cause the synaptic vesicles to fuse with the presynaptic neurone
|
|
calcium
|
|
this releases ____ from the vesicles into the synaptic cleft which diffuses to the postsynaptic membrane of the muscle fibre
|
|
acetylcholine
|
|
this opens ____ ion channels and depolarises the membrane
|
|
sodium
|
|
acetylcholine is broken down by ____ and the products diffuse back into the presynaptic neurone
|
|
acetylcholinesterase
|
|
evidence for the ____ mechanism of muscle contraction: I band, H zone, and sarcomere narrows but the A band remains the same width
|
|
sliding filament
|
|
thus it follow the ____ filaments have not become shorter
|
|
myosin
|
|
____ comprises of a fibrous protein tail and a globular protein head
|
|
myosin
|
|
____ is a globular protein whose molecules are twisted to form a helical strand
|
|
actin
|
|
____ forms long thin strands that wind around actin filaments
|
|
tropomyosin
|
|
(1) once the action potential has crossed the neuromuscular junction, it travels into the fibre trough a system of T-tubules that branch throughout the ____
|
|
sarcoplasm
|
|
(2) the ____ has actively transported calcium ions from the sarcoplasm so there is a very low concentration
|
|
sarcoplasmic reticulum
|
|
(3) calcium ions are released and bind to ____, changing its shape and displacing tropomyosin from blocking the actin filament
|
|
troponin
|
|
(4) the myosin heads attach to the actin filament by the ____ molecules attached to their heads
|
|
ADP
|
|
(5) the myosin ____ changes position and the actin filaments slide past, the ADP is released
|
|
head
|
|
(6) an ____ molecule fixes to the myosin head and causes it to detach from the acin
|
|
ATP
|
|
(7) calcium ions activate the ____ and hydrolysis of the ATP allows the myosin head to be cocked again
|
|
ATP hydrolase
|
|
when the muscles are relaxed, calcium ions are actively transported back into the sarcoplasmic reticulum and ____ blocks the filament again
|
|
tropomyosin
|
|
____ is a reserve supply of phosphate available immediately to form ATP
|
|
phosphocreatine
|
|
the store is replenished using phosphate from ____ when the muscle is relaxed
|
|
ATP
|
|
necessary to have the store as a method of rapidly generating ATP ____ when ATP demand exceeds oxygen availability
|
|
anerobically
|
|
____ muscle fibres contract more slowly, adapted to endurance work, adapted for aerobic respiration
|
|
slow twitch
|
|
(1) large store of ____ (oxygen storage molecule) which gives them a red colour
|
|
myoglobin
|
|
(2) good blood supply to deliver oxygen and glucose and numerous ____ to produce ATP
|
|
mitochondria
|
|
____ muscle fibres contract more rapidly and powerfully, adapted to intense exercise
|
|
fast twitch
|
|
(1) thicker and more numerous ____ filaments
|
|
myosin
|
|
(2) high concentration of enzymes involved in ____ respiration
|
|
anaerobic
|
|
(3) large stores of glycogen and ____
|
|
phosphocreatine
|
|
the maintenance of a stable internal environment
|
|
homeostasis
|
|
necessary to maintain pH and temperature to allow for normal ____ function
|
|
enzyme
|
|
necessary to maintain blood water potential (so also ____ concentration) to prevent bursting or shrinking of cells
|
|
glucose
|
|
____ feedback mechanisms in both directions give a greater degree of control
|
|
negative
|
|
____ is produced in times of excitement or stress
|
|
adrenaline
|
|
(1) binds to a transmembrane protein receptor within the cell surface membrane of a ____ cell
|
|
liver
|
|
(2) changes the shape of a protein on the inside of the membrane and activates ____
|
|
adenyl cyclase
|
|
(3) this converts ATP to ____
|
|
cyclic AMP
|
|
(4) this acts as a secondary messenger that activates a ____ by changing its shape
|
|
protein kinase
|
|
(5) this catalyses conversion of glycogen to ____
|
|
glucose
|
|
conversion of glucose into glycogen
|
|
glycogenesis
|
|
breakdown of glycogen to glucose
|
|
glycogenolysis
|
|
production of glucose from sources other than carbohydrate
|
|
gluconeogenesis
|
|
when insulin is released, it causes (1) activation of enzymes involved in glycogenesis
|
|
insulin
|
|
(2) ____ containing glucose transport carrier proteins fuse with the cell surface membrane to increase glucose absorption
|
|
vesicles
|
|
(3) a change in the ____ structure of glucose carrier proteins causing them to open
|
|
tertiary
|
|
lowers blood glucose concentration by (1) increasing rate of absorption of ____ into the cells
|
|
glucose
|
|
(2) increasing rates of cellular respiration, glycogenesis, and conversion of glucose into ____
|
|
fat
|
|
when ____ is released it binds to receptors on liver cells and activates enzymes involved in glycogenolysis and gluconeogenesis
|
|
glucagon
|
|
diabetes where the body cannot produce insulin due to an autoimmune attack on the beta-cells of the islets of Langerhans
|
|
Type I
|
|
controlled by injections of ____ and usually begins in childhood
|
|
insulin
|
|
diabetes where glycoprotein receptors lose responsiveness to insulin or there is an inadequate supply of insulin from the pancreas
|
|
Type II
|
|
usually controlled by regulating ____ intake but may be supplemented by insulin injections or drugs that slow rate of glucose absorption
|
|
carbohydate
|
|
incidence of type II diabetes is ____ so responses of public bodies are important in determining health outcomes
|
|
increasing
|
|
e.g. promote healthy eating and physical activity, ask government to improve laws around ____ labelling
|
|
nutrition
|
|
food industry sometimes reformulate products to reduce sugar/salt/fat content but also need to make ____ so promote unhealthy foods still
|
|
profit
|
|
control of water potential of the blood
|
|
osmoregulation
|
|
functional unit of the kidney
|
|
nephron
|
|
the closed end at the start of the nephron, cup-shaped
|
|
Bowman's capsule
|
|
mass of blood capillaries surrounded by the Bowman's capsule
|
|
glomerulus
|
|
a series of loops surrounded by blood capillaries. its walls are made of epithelial cells which have microvilli, connects Bowman's capsule to the loop of Henle
|
|
proximal convoluted tubule
|
|
a long, hairpin loop that extends from the cortex into the medulla of the kidney and back again. surrounded by blood capillaries
|
|
loop of Henle
|
|
a second series of loops surrounded by blood capillaries
|
|
distal convoluted tubule
|
|
a tube into which a number of distal convoluted tubules from a number of nephrons empty
|
|
collecting duct
|
|
(1) blood enters the kidney through the ____ artery
|
|
renal
|
|
this branches to give the ____ which each enter a Bowman's capsule
|
|
afferent arterioles
|
|
____ of the afferent arteriole is greater than ____ of the efferent arteriole, causing a buildup of hydrostatic pressure in the glomerulus
|
|
diameter
|
|
water, glucose and mineral ions are squeezed out of the capillary and form the ____
|
|
glomerular filtrate
|
|
the glomerular ____ prevents large proteins entering the filtrate
|
|
basement membrane
|
|
the ____ that make up the renal capsule have gaps between them for filtrate to pass through
|
|
podocytes
|
|
the ____ of the glomerular capillaries also has gaps
|
|
endothelium
|
|
the ____ are adapted by: microvilli for a large surface area, many mitochondria to provide ATP for active transport
|
|
podocytes
|
|
water and ____ are reabsorbed by the proximal convoluted tubule (____ by cotransport with sodium ions)
|
|
glucose
|
|
the loop of Henle acts as a ____ multiplier to absorb water
|
|
counter current
|
|
(1) sodium ions are actively transported out of the water-impermeable ____ limb
|
|
ascending limb
|
|
(2) this creates a low water potential in the ____ region between the limbs
|
|
interstitial
|
|
(3) water passes out of the permeable ____ limb by osmosis into the interstitial space and into blood capillaries
|
|
descending
|
|
(4) sodium ions diffuse and are actively transported out all the way up the ascending limb to maintain a ____ gradient
|
|
water potential
|
|
the ____ makes final adjustments to the water and ions that are reabsorbed
|
|
distal convoluted tubule
|
|
____ hormone alters permeability of the distal convoluted tubule to water
|
|
antidiuretic
|
|
it is released by the ____ gland and more ADH leads to more water being reabsorbed
|
|
pituitary
|
|
the genetic constitution of an organism
|
|
genotype
|
|
the expression of this genetic constitution and its interaction with the environment
|
|
phenotype
|
|
genes located on sex chromosomes
|
|
sex linked
|
|
multiple genes located on the same autosome
|
|
autosomally linked
|
|
where one gene influences the expression of another gene. can be dominant or recessive
|
|
epistasis
|
|
two different alleles are both fully and equally expressed in an individual's phenotype
|
|
codominant
|
|
monohybrid and ____ crosses can be constructed to interpret the results of a genetic cross
|
|
dihybrid
|
|
practice questions on genetic crosses are the most efficient method of revision (type ok)
|
|
ok
|
|
a group of organisms of the same species occupying a particular space at a particular time that can potentially interbreed
|
|
population
|
|
all the alleles of all the genes of all the individuals in a population at a given time
|
|
gene pool
|
|
the number of times an allele occurs within the gene pool
|
|
allele frequency
|
|
____ equations can be used to calculate allelic frequencies in a population. assumptions:
|
|
Hardy-Weinberg
|
|
(1) no ____
|
|
mutations
|
|
(2) the population is ____ (no flow of alleles in or out)
|
|
isolated
|
|
(3) there is no ____ so all alleles equally likely to be passed on
|
|
selection
|
|
(4) population is ____
|
|
large
|
|
(5) mating is ____
|
|
random
|
|
p^2 + 2pq + q^2 = ____ and p + q = ____
|
|
1
|
|
natural selection causes changes in ____ frequency if the new mutation provides a benefit to the phenotype
|
|
allele
|
|
eliminates extremes of the phenotypic range within a population and with it the capacity for evolutionary change
|
|
stabilising selection
|
|
a change in conditions changes the optimum value for survival in the normal distribution of a phenotype
|
|
directional selection
|
|
extreme phenotypes are favoured at the expense of intermediates
|
|
disruptive selection
|
|
____ separation of two populations can result in accumulation of differences in their gene pools that prevent successful breeding
|
|
reproductive
|
|
____ speciation: two populations are geographically isolated
|
|
allopatric
|
|
____ speciation: two populations are in the same area but are reproductively separated (e.g. fertile at different times of year)
|
|
sympatric
|
|
change in allele frequencies within a population from one generation to the next, driven by chance
|
|
genetic drift
|
|
the populations of different species in an area
|
|
community
|
|
a community and the non-living components of its environment
|
|
ecosystem
|
|
the specific functional role and space an organism occupies within an ecosystem
|
|
ecological niche
|
|
an ecosystem supports a certain size of population of a species (the ____)
|
|
carrying capacity
|
|
population size varies due to inter and intraspecific ____ and the effects of abiotic factors
|
|
competition
|
|
mark-release recapture assumptions: (1) proportion of ____ to un____ individuals does not change between samples
|
|
marked
|
|
(2) the marked individuals have sufficient time to distribute evenly within the ____
|
|
population
|
|
(3) no immigration, emigration, births or ____
|
|
deaths
|
|
(4) the method of ____ing does not harm the individual, and is not lost or rubbed off
|
|
mark
|
|
succession: (1) the ____ species colonises an environment (e.g. lichens)
|
|
pioneer
|
|
(2) ____ of the base rock by the pioneer species produces sand or soil
|
|
weathering
|
|
(3) these species die, decompose, and release sufficient nutrients to support a ____ of small plants
|
|
community
|
|
(4) continued erosion of the rock builds up soil, which is contributed to by the ____ matter from dead plants
|
|
organic
|
|
this holds ____ which makes it easier for other plants to grow
|
|
water
|
|
each generation of species make it less ____ for the organisms that follow
|
|
hostile
|
|
(5) the new plants also provide more ____ sources and ____ webs develop
|
|
food
|
|
(6) a ____ community forms, with trees, animals, other plants. there is high biodiversity and it is stable over time
|
|
climax
|
|
____ of habitats frequently involves management of succession
|
|
conservation
|
|
you need to manage conflict between human needs and conservation to maintain ____ of natural resources
|
|
sustainability
|
|
cells can control their metabolic activities by regulating ____ and translation of their genome
|
|
transcription
|
|
mutation that adds a base
|
|
addition
|
|
mutation that removes a base
|
|
deletion
|
|
mutation that changes one base for another
|
|
substitution
|
|
mutation that flips a section around 180 degrees
|
|
inversion
|
|
mutation that duplicates a section
|
|
duplication
|
|
mutation where a segment of chromosome breaks off and attaches to a non-homologous chromosome or another part of the same chromosome
|
|
translocation
|
|
mutations are ____ but frequency is increased by mutagenic agents
|
|
spontaneous
|
|
a ____ shift changes all codons downstream from the mutation
|
|
frame
|
|
____ cells can divide and produce any type of body cell, found in early mammalian embryos
|
|
totipotent
|
|
____ cells can form all body cell types but placenta, found in embryos
|
|
pluripotent
|
|
multi____ and uni____ cells are found in mature mammals and can divide to form a limited number of cell types
|
|
potent
|
|
unipotent cells are derived from ____ cells and can only differentiate into one type of cell
|
|
multipotent
|
|
e.g. ____ which are heart muscle cells that can divide to produce new heart tissue and repair damaged heart muscle
|
|
cardiomyocytes
|
|
____ can be produced from adult somatic cells using transcription factors
|
|
induced pluripotent cells
|
|
pluripotent ____ treatments pros: alleviate human suffering, use embryos from fertility treatments that would otherwise be destroyed, no harm to a person
|
|
stem cell
|
|
cons: undermines respect for human life, move towards reproductive ____
|
|
cloning
|
|
stem cells obtained from adult ____ have restricted medical benefits
|
|
bone marrow
|
|
____ is a steroid hormone that helps initiate transcription
|
|
oestrogen
|
|
for transcription to begin, a ____ must bind to a promoter region so the DNA can be transcribed
|
|
transcriptional factor
|
|
(1) oestrogen is ____ so diffuses through the phospholipid bilayer
|
|
lipid soluble
|
|
(2) in the cytoplasm, binds to a receptor molecule on the transcriptional factor with a ____ shape
|
|
complementary
|
|
(3) changes the shape of the ____ binding site on the transcriptional factor and allows it to bind to ____
|
|
DNA
|
|
(4) the complex now enters the nucleus through a nuclear pore and binds to the ____ region on the gene and stimulates transcription
|
|
promoter
|
|
heritable changes in gene function without changes to the DNA base sequence
|
|
epigenetics
|
|
the ____ determines the shape of the DNA-histone complex
|
|
epigenome
|
|
the epigenome responds to environmental changes to vary which ____ are silenced and which are not
|
|
genes
|
|
in early development, ____ by the mother shapes the epigenome. after birth, environmental factors affect it instead
|
|
nutrition
|
|
when the association of DNA with ____ is weak DNA is more accessible by transcriptional factors
|
|
histones
|
|
____ of histones decreases the positive charge of histones and decreases attraction to DNA
|
|
acetylation
|
|
____ of the cytosine bases prevents binding of transcriptional factors
|
|
methylation
|
|
epigenetic treatments can be used to treat cancers, e.g. decreasing ____ of tumour suppressor genes
|
|
methylation
|
|
____ is breaking down mRNA before translation
|
|
RNA interference
|
|
siRNA
|
|
small interfering RNA
|
|
(1) enzyme cuts double stranded ____ into smaller sections of siRNA
|
|
RNA
|
|
(2) one of the two siRNA strands combines with an ____
|
|
enzyme
|
|
(3) the siRNA pairs its bases to the complementary ones on the ____
|
|
mRNA
|
|
(4) the enzyme cuts the mRNA into smaller pieces and prevens ____
|
|
translation
|
|
malignant vs benign tumours: both can grow very ____
|
|
large
|
|
benign have a normal cell ____ whereas malignant have a larger and darker ____ due to an abundance of DNA
|
|
nucleus
|
|
benign tumours often have ____ cells but in malignant ones cells become un____
|
|
specialised
|
|
malignant tumours ____ and form secondary tumours but benign ones do not because they produce adhesion molecules
|
|
metastasise
|
|
benign tumours are compacted by a capsule of dense ____ but malignant ones are not
|
|
tissue
|
|
____ tumours are less likely to be life-threatening unless they disrupt function of a vital organ
|
|
benign
|
|
benign tumours tend to have localised effects whereas malignant ones have ____ effects
|
|
systemic
|
|
benign tumours can usually be removed by surgery, malignant tumours usually require radio____ and/or chemo____ as well
|
|
therapy
|
|
____ tumours reoccur after treatment more frequently
|
|
malignant
|
|
cancer cells are derived from a single mutant cell whose mutation causes uncontrolled ____
|
|
mitosis
|
|
a further ____ in descendent cells can cause subsequent cells to have abnormal growth or appearance
|
|
mutation
|
|
mutations of proto-oncogenes, which stimulate a cell to divide when growth factors attach to a protein receptor on its cell-membrane surface
|
|
oncogenes
|
|
these mutations cause the ____ to be permanently switched on for one of two reasons:
|
|
proto oncogene
|
|
(1) the receptor protein on the cell surface membrane is permanently activated even in the absence of ____
|
|
growth factors
|
|
(2) the oncogene may code for a growth factor that is then produced in excessive amounts, stimulating excessive ____
|
|
mitosis
|
|
____ slow down cell division, repair mistakes in DNA, tell a cell when to die
|
|
tumour suppressor genes
|
|
cell death
|
|
apoptosis
|
|
____ of a tumour suppressor gene can occur to it being switched off
|
|
hypermethylation
|
|
probability of developing breast cancer increases after the ____ because the fat cells of the breast start producing oestrogen
|
|
menopause
|
|
this is because oestrogen promotes transcription and can cause proto-oncogenes in breast tissue to develop into ____
|
|
oncogenes
|
|
genetic and ____ factors can increase cancer risk
|
|
environmental
|
|
determining the genome of simpler organisms allows the ____ of the organism to be determined
|
|
proteome
|
|
this can be applied in ____ production by identification of specific antigens
|
|
vaccine
|
|
this is not possible in more complex organisms due to the presence of ____
|
|
introns
|
|
____ methods are continuously updated and have become automated
|
|
sequencing
|
|
____ DNA technology involves the transfer of fragments of DNA from one organism or species to another
|
|
recombinant
|
|
the genetic code is universal so transferred DNA is translated within cells of the recipient ____ organism
|
|
transgenic
|
|
process: (1) DNA fragment is ____
|
|
isolated
|
|
(2) DNA fragment is inserted into a ____
|
|
vector
|
|
(3) ____ of the DNA into host cells
|
|
transformation
|
|
(4) identification of the host cells that have taken up the gene by use of gene ____
|
|
markers
|
|
(5) ____ of the successful host cells
|
|
cloning
|
|
____ of DNA can be produced by one of three methods:
|
|
fragments
|
|
(1) conversion of mRNA to complementary DNA (cDNA) using ____
|
|
reverse transcriptase
|
|
(2) using ____ enzymes to cut out a fragment containing the desired gene from DNA
|
|
restriction endonuclease
|
|
(3) using a ____ to assemble the gene from oligonucleotides
|
|
gene machine
|
|
a series of small, overlapping single strands of nucleotides
|
|
oligonucleotides
|
|
____ gene cloning uses vectors to transfer fragments to a host cell
|
|
in vivo
|
|
restriction endonucleases cut the DNA and target gene at ____
|
|
recognition sites
|
|
this gives complementary ____ which means the DNA can incorporate the gene
|
|
sticky ends
|
|
when the sticky ends have paired up, ____ binds the phosphate-sugar frameworks of the two sections
|
|
DNA ligase
|
|
before insertion, a promoter region is added for ____ to bind at and a terminator region for ____ to detach at
|
|
RNA polymerase
|
|
the fragments are mixed with ____ cut with the same restriction endonuclease
|
|
plasmids
|
|
the plasmids are mixed with the cells in a medium containing ____ and temperature changes to increase membrane permeability
|
|
calcium ions
|
|
to identify which cells have take up a plasmid, use ____ as the cells with the resistant gene from the plasmid will survive
|
|
antibiotic resistance
|
|
then from these cells, identify if the gene has been taken up using another ____ gene, e.g. one that is fluorescent
|
|
marker
|
|
____ cloning uses the polymerase chain reaction
|
|
in vitro
|
|
PCR requires: the DNA fragment, ____, primers, nucleotides, and a thermocycler
|
|
DNA polymerase
|
|
short sequences of nucleotides that have a set of bases complementary to those at one end of each of the two DNA fragments
|
|
primers
|
|
a computer controlled machine that varies temperatures precisely over a period of time
|
|
thermocycler
|
|
PCR: (1) temperature increased to ____C to break hydrogen bonds between the strands
|
|
95
|
|
(2) ____ of the primers
|
|
annealing
|
|
the mixture is cooled to ____C causing the primers to join to their complementary bases at the end of the DNA fragment
|
|
55
|
|
these primers allow ____ to attach and prevent the two strands from rejoining
|
|
DNA polymerase
|
|
(3) temperature increased to ____C and the DNA polymerase synthesises the new DNA strand from the nucleotides
|
|
72
|
|
the cycle is repeated and number of strands is ____ every time
|
|
doubled
|
|
____ is more rapid and does not require living cells
|
|
in vitro
|
|
____ is precise, more accurate, low risk of contamination, useful for gene therapy, useful to produce transgenic bacteria that produce gene products
|
|
in vivo
|
|
____ DNA technology benefits: treats disease, crops engineered to prevent disease or have environmental advantages, bacteria cloned to break down oil slicks
|
|
recombinant
|
|
risks: can't predict ____ consequences of releasing GM organisms, antibiotic resistance marker could spread to harmful bacteria, eugenics concerns
|
|
ecological
|
|
short, single-stranded lengths of DNA that have some sort of label attached to make it easily identifiable
|
|
DNA probes
|
|
where a section of DNA or RNA is combined with a single-stranded section of DNA which has complementary bases
|
|
DNA hybridisation
|
|
you can identify an ____ of a gene with a probe in the following way:
|
|
allele
|
|
(1) determine the allele ____ sequence using sequencing or genetic libraries
|
|
base
|
|
(2) make copies of the probe using the ____
|
|
polymerase chain reaction/PCR
|
|
(3) heat the ____ stranded DNA to separate the strands
|
|
double
|
|
(4) mix the strands with the probe so the probe binds to the DNA - ____
|
|
hybridisation
|
|
(5) wash to remove unattached probes then identify if a probe has bound using a ____ or fluorescent marker
|
|
radioactive
|
|
this can be used to screen patients for heritable conditions, drug responses, and health risks - allows for ____ medicine
|
|
personalised
|
|
a form of social work relating to heritable diseases and likelihood/manageability of it in offspring
|
|
genetic counselling
|
|
VNTRs
|
|
variable number tandem repeats
|
|
VNTRs are non-____ base sequences with lengths unique to everyone. the more similar they are, the more closely related two individuals are
|
|
coding
|
|
making of a genetic ____: (1) extract the DNA from a sample and increase quantity using PCR
|
|
fingerprint
|
|
(2) cut the DNA into fragments using ____
|
|
restriction endonucleases
|
|
(3) separate the fragments by size by ____
|
|
gel electrophoresis
|
|
(4) immerse the gel in ____ to separate the strands
|
|
alkali
|
|
(5) mix with different radioactively marked probes complementary to ____
|
|
VNTRs
|
|
(6) develop by placing on ____ film
|
|
X-ray
|
|
uses of DNA fingerprinting include: (1) resolving questions of ____
|
|
paternity
|
|
all bands on an individual's ____ must correspond to one of the parents
|
|
genetic fingerprint
|
|
(2) ____ science: comparing a DNA sample from a crime scene to one taken from a suspect
|
|
forensic
|
|
(3) ____ diagnosis to investigate if someone has a genetic disease vulnerability
|
|
medical
|
|
(4) plant and animal breeding, for example to prevent undesirable ____
|
|
inbreeding
|
