Responding to Change Random Retrieval

This quiz contains all the questions in the Responding to Change section. The website will pick 20 questions at random.

1 / 20

One role of ATP in muscle contraction is to provide the energy required for the 'powerstroke' of the myosin head. What is the other use of ATP in muscle contraction?

To 'reset' the myosin head.

To break the actin-myosin cross bridge.

To release Calcium ions.

2 / 20

In the sliding filament theory, what causes the actin-myosin binding site to be exposed?

The hydrolysis of ATP.

An influx of calcium ions into the sarcoplasmic eticulum.

The release of calcium ions, out of the sarcoplasmic reticulum.

3 / 20

The image above shows a muscle fibre. What is the function of organelle E?

Generation of ATP

Transmission of an action potential to all fibrils.

Storage and release of calcium ions.

4 / 20

What type of sodium channels are opened when a Pacinian corpuscle is stimulated?

Voltage-gated Sodium Channels

Ligand-Gated Sodium Channels

Stretch-mediated Sodium Channels

5 / 20

When a stimulus is detected by a receptor, it generates a potential difference across it's plasma membrane. What is the name of this potential difference?

Action potential

Generator potential

Receptor potential

6 / 20

Doctors investigated two ways of measuring the effect of general anaesthetics. In one method they timed how long it took to stop blinking, and then repeated the investigation using a machine to record when brain activity showed they were unconscious. Blinking involves cholinergic synapses. Anaesthetic S is a similar shape to acetylcholine. Suggest how anaesthetic S stops the transmission across the synapse.

S acts as an agonist

S acts as an antagonist

S inhibits the enzymes that break down acetylcholine

7 / 20

GABA is a neurotransmitter released in some inhibitory synapses in the brain. GABA causes negatively charged chloride ions to enter postsynaptic neurones. Explain how this inhibits postsynaptic neurones

The post synaptic neurone becomes hyperpolarised , so more sodium ions are required to reach threshold.

The post synaptic neurone becomes less polarised , so less sodium ions are required to reach threshold.

8 / 20

What reduces the concentration of neurotransmitter in a synapse after it has diffused across?

The neurotransmitter is actively reabsorbed whole, via endocytosis.

An enzyme breaks the neurotransmitter down.

Nothing, it just diffuses until a vey low concentration is reached.

9 / 20

Once an action potential has been generated, why is the wave of depolarisation only in one direction?

Hyperpolarisation means potassium channels are working at capacity.

Sodium ions only ever diffuse away from the cell body.

The refractory period means that voltage gated channels are 'locked' closed.

10 / 20

When an action potential is generated, there is a temporary reversal of the polarity of the neurone membrane at that point. Does this mean that:

The inside becomes more negative compared to the outside.

The outside becomes more negative compared to the inside.

The outside becomes more positive compared to the inside.

11 / 20

Which of the events (A - F above) starts depolarisation? Type the letter in the box

12 / 20

Name stage 5 on the above diagram ( spell it carefully!)

13 / 20

Name protein B in the above diagram.

Sodium Ion Channel

Potassium Ion Channel

Sodium-potassium pump

14 / 20

In the above experiment on woodlice, how would you make the method more valid?

Change the light intensity on the light side with each repeat.

Place each woodlice in the centre of the chamber at the start of each repeat.

Make the dark- side dark and damp.

15 / 20

In the above experiment on woodlice, what is the Independent variable?

Light Intensity

Number of woodlice

Length of time you leave the woodlice in the chamber

16 / 20

Woodlice are more stationary with increased humidity. Is this taxis or kinesis?

Taxis

Kinesis

17 / 20

Mica is like thin glass, and is impermeable to most substances. What does Boysen Jensen's experiment inserting mica show ?

That chemicals diffuse down the shoot from the tip.

That chemicals move away from light.

That chemicals move away from light and diffuse down from the tip.

18 / 20

Which of these statements about Went's experiment is NOT true?

That plant growth is probably caused by a chemical which can diffuse.

That a substance produced in the tip can move (diffuse) into gelatin, and then out again.

Gelatin blocks stimulate growth.

19 / 20

What does Darwin's experiment where he placed a black cover over the tip show?

That directional light on the tip effects the direction of growth.

That directional light does not effect direction of growth.

That aluminium foil is toxic to shoot tips.

20 / 20

In root tips growing parallel to the soil, where will the highest concentration of IAA be found ?

The upper surface

The lower surface

Both even

Your score is

0%

Recent Posts

Categories