Neurones

A scientist uses the method shown in Figure 7 to investigate the reaction times of some students.

Which measurement should be recorded to compare reaction times?

Figure 8 shows the results of five students.

Which is the mean of the results in Figure 8?

Explain which of the five students had the slowest reaction time.

Give two variables that need to be controlled during this investigation.

Figure 9 shows a motor neurone.

State the role of a motor neurone in a reflex arc.

Explain the function of the myelin sheath.

Describe how a nerve impulse passes across the gap between two neurones.

Reaction time can be tested by dropping a ruler and measuring the distance it travels before it is caught.

Figure 6 shows how the test works.

This method was used to test the reaction times of three students.

Each student completed the test five times and the distances were recorded.

State how the median distance for each student could be determined from the results.

State and explain one variable that needs to be controlled in this investigation.

Figure 7 shows the results recorded for the three students.

Explain one conclusion that can be made from the results in Figure 7.

A student wanted to investigate the effect of two different drinks containing caffeine on reaction time using this method.

Devise a plan the student could use.

Figure 8 shows a myelinated sensory neurone.

Identify structure Z.

Figure 9 shows how the diameter of neurones affects the speed of electrical impulses.

Comment on how the diameter of a neurone affects the speed of the electrical impulses.

Motor neurones are found in the nervous system.

Figure 8 shows a motor neurone.

Draw an arrow on Figure 8 to show the direction of travel of an electrical impulse along the motor neurone.

Name both structure K and structure L.

K_........

L_........

Figure 9 shows part of a reflex arc in the spinal cord.

Describe how an impulse passes from the relay neurone to the motor neurone.

Explain the function of a reflex arc.

A scientist investigated the reaction times of five students using a computer program.

The computer screen showed a blue square at the start.

As soon as the blue square turned yellow, each student had to press a key on the keyboard as fast as possible.

Figure 10 shows the results for the five students.

Which is the median result for these students?

The scientist wanted to investigate if the colours of the squares used on the computer program affected reaction time.

The computer program started with blue squares that turned into yellow squares.

Describe how the scientist could compare the reaction times of these students when they respond to red squares turning into yellow squares.

Figure 1 shows part of a reflex arc in the spinal cord.

Describe how an impulse passes from the relay neurone to the motor neurone.

Explain the function of a reflex arc.

A scientist investigated the reaction times of five students using a computer program.

The computer screen showed a blue square at the start.

As soon as the blue square turned yellow, each student had to press a key on the keyboard as fast as possible.

Figure 2 shows the results for the five students.

Which is the median result for these students?

The scientist wanted to investigate if the colours of the squares used on the computer program affected reaction time.

The computer program started with blue squares that turned into yellow squares.

Describe how the scientist could compare the reaction times of these students when they respond to red squares turning into yellow squares.

The reaction time of five people was tested using a computer.

These people were then given 100 cm³ of a liquid to drink.

Their reaction times were recorded 10 minutes after drinking the liquid.

Figure 6 shows the results.

Calculate the mean difference in reaction time.

Give your answer in milliseconds.

_........ ms

The drinks manufacturer wants to advertise the effect of the drink on reaction time.

The manufacture needs to confirm the effect on reaction time by improving the investigation.

Give two improvements the manufacturer would need to make to this investigation.

Figure 7 shows a neurone.

Name the type of neurone shown in Figure 7.

Which row identifies structure P and structure Q ?

*(c) Some painkillers prevent neurotransmitters binding to receptors in a synapse.

Explain how a signal is transmitted at a synapse and how the painkillers reduce the pain felt by the person.

Figure 8 shows the number of neurones in the brain of different animals.

Calculate the difference between the number of neurones in the brain of the rat and the brain of the frog.

Give your answer in standard form.

_........ neurones

Most neurones in the brain are unmyelinated whereas motor neurones are myelinated.

Explain why myelination is needed on motor neurones but not on neurones in the brain.

Figure 9 shows a sensory neurone.

Label the axon on Figure 9.

Describe the role of sensory neurones.

Explain how impulses are transmitted at synapses.