WJEC A-Level Biology Unit 3 Energy, Homeostasis and the Environment overview quiz quiz

The stroma of the chloroplast

The mitochondrial matrix

The thylakoid membranes

The cell cytoplasm

Oxygen and water

Carbon dioxide and glucose

RuBP and rubisco

ATP and reduced NADP

It is the final electron acceptor, forming water

It is the first electron donor at the start of the electron transport chain

It is used directly in glycolysis to split the glucose molecule into pyruvate

It is released as a waste product of the link reaction and the Krebs cycle

The mitochondrial matrix

The cytoplasm

The inner mitochondrial membrane

The thylakoid

The initial lag phase

The log (exponential) phase

Stationary phase

The final death phase

Most of the energy is simply destroyed as it moves up the food chain

The producers at the base absorb all of the available energy from sunlight

Energy is steadily converted into water at each trophic level in the chain

Energy is lost in respiration as heat, and in faeces and excretion

Nitrifying bacteria

Nitrogen-fixing bacteria

Denitrifying bacteria

Decomposing bacteria

Red blood cells and large proteins

Water, glucose, ions and urea

Only urea

Nothing; the blood is unchanged

Less water is reabsorbed, giving a large volume of very dilute urine

Glucose is reabsorbed faster from the filtrate in the proximal tubule

More water is reabsorbed, giving a small volume of concentrated urine

The glomerular filtration rate falls right down to zero in the kidney

Potassium ions diffuse out of the axon through voltage-gated channels

The sodium-potassium pump stops working and active transport ceases

Chloride ions diffuse into the axon, making the inside more negative

Sodium ions diffuse into the axon, making the inside less negative

Only the presynaptic neurone releases neurotransmitter and only the postsynaptic membrane has receptors

The synaptic cleft is far too wide for any of the neurotransmitter to diffuse across it in two directions

Neurotransmitter molecules are physically unable to diffuse across the synaptic cleft at all

Calcium ions actively block the reverse direction, stopping the signal from travelling backwards

The myelinated axon is always much wider than an unmyelinated one of the same type

The action potential jumps between nodes of Ranvier in saltatory conduction

Myelin increases the resting potential of the axon membrane along its whole length

Far more neurotransmitter is released at each synapse along a myelinated neurone