Responding to Change Random Retrieval

When light falls on cells 1 and 2, only one spot of light is seen. But, when light falls on cells 2 and 3, two spots of light are seen. Say why?

The cone density is highest on the fovea in the centre of the retina. In a human fovea there are 150 000 cones per mm2. The diameter of a human fovea is 1.2 mm. Calculate the number of cones on the human fovea.

The diagram above shows a cross section of a human eye. Name layer A (Type your answer).

Name part B on the above diagram (type your answer).

The table shows the results on investigating how fast an anaesthetic works. Using the results from the machine, was there a significant difference between anaesthetics S and Q?

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.

Synaptic knobs contain mitochondria, which of the following is NOT a use of ATP in the presynaptic neurone?

What effect do inhibitory synapses have on the post-synaptic membrane?

True or False - The speed of conduction along an unmyelinated neurone is around 5 m/s ( jogging pace).

True or False: A stronger stimulus will generate more frequent action potentials.

True or false: If more sodium channels are opened by a stimulus, then the action potential which is generated is bigger.

In order for an action potential to be triggered, a certain number of sodium channels must open, each setting a change in the potential difference.

What name is given to this change in potential difference that must be reached ? (Type your answer)

Stimulation ( either by a generator potential in a receptor cell or a neurotransmitter binding to a receptor on a postsynaptic membrane) caused which type of channel to open?

Across a resting human neurone plasma membrane, what is the average potential difference?

Honey bees can detect the polarised light from the sun and use it to navigate even in cloudy weather. Is this taxis or kinesis?

What does Boysen and Jensen's experiment using agar show?

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

Which of the following is true?

What word describes the growth response of a plant to a stimulus?

Plant responses to stimuli are controlled by what?