Response & Regulation (WJEC GCSE Biology): Exam Questions

A class of year 11 boys were investigating reaction time. The students suggested the following hypothesis:

“Year 11 students have faster reaction times than teachers”

A computer program was used to record the reaction time. Each individual had to press a button on the keyboard when the screen turned green (Image 8.1). Each individual had three attempts and the mean value was recorded.

Image 8.1

State the stimulus and the receptor involved in this investigation.

[2]

Stimulus:...................
Receptor:..................

(ii) Describe how the information travels from the receptor to the central nervous system.

[2]

The results for the students are shown in Table 8.2 and the teachers in Table 8.3.

Table 8.2

Table 8.3

(i) Complete Table 8.3 by calculating the mean reaction time for the teachers to the nearest whole number.

[2]

(ii) Evaluate the extent to which the results in Tables 8.2 and 8.3 support the students’ hypothesis.

[2]

You should do this by giving:

• one piece of evidence that supports the hypothesis

• one piece of evidence that does not support the hypothesis Evidence that supports hypothesis

Evidence that supports hypothesis..................................

Evidence that does not support the hypothesis.................................

(iii) State one variable that should have been controlled in this investigation.

[1]

(iv) State one way that the students could have increased their confidence in their results.

[1]

Researchers have created an artificial eye that models the constriction and dilation of the pupil. The change in size of the pupil in response to changing light levels is an example of a reflex arc.

Image 3.1A shows a diagram of the eye and Image 3.1B shows parts from the artificial eye model.

Draw an arrow labelled A on Image 3.1A to show the sclera.

State two properties of a reflex arc.

1. .......................

2. .......................

State the name of the part of the eye represented by the artificial muscle fibre in Image 3.1B

Describe how the diameter of the pupil changes in response to bright light. State the advantage of this change to the eye.

In 2010, scientists in China carried out an investigation to compare the growth of seeds on Earth and on the moon.

They sent seeds in a sealed container on board a rocket to the moon. The sealed container contained all the necessary conditions to allow the seeds to grow. The sealed container had a small window at the top, which allowed sunlight to reach the growing seeds. The container was at the same atmospheric pressure as the Earth.

An identical sealed container which contained identical seeds was kept on Earth. The scientists observed the seeds growing in both containers.

Images 5.1A and 5.1B show the results of the investigations.

State the name of:

(i) the growth response shown by the shoots in Image 5.1A and Image 5.1B.

[1]

(ii) the hormone that controls growth responses in plants.

[1]

(i) Describe one difference in the growth of the roots in Images 5.1A and 5.1B.

[1]

(ii) Suggest one reason for the difference between the growth of seeds grown on the moon and those grown on Earth.

[1]

State the term used for carrying out an identical investigation on Earth.
Suggest why this is important.

Use some of the words from the box to complete the sentences about the nervous system.

Sense organs contain groups of ……………......................………… cells which respond to stimuli. In the eye, cells in the ……………......................………… respond to the stimulus of …………….........................… and send ……………......................………… impulses to the brain along neurones

The diagram shows how the eye closes automatically (blinks) when something which may be harmful approaches.

Select the scientific term (A, B or C) for this type of action from the list below

A a release action
B a relax action
C a reflex action

Apart from happening automatically, state two other properties of actions such as blinking.

1..........................
2.........................

Image 2.1 shows a parsley plant (Petroselinum sp.) growing on a windowsill.

Image 2.1

The plant is showing a response to light called positive phototropism.

(i) State which one of arrows A, B, C or D on Image 2.1 shows the main direction of light.

[1]

Answer ......................................

(ii) Underline the name of the plant hormone involved in the response.

[1]

insulin amylase auxin

Images 2.2 and 2.3 show an investigation into the effect of gravity on the growth of a seedling which has been placed horizontally on a laboratory bench.

(i) Complete Image 2.3 by drawing the root as you would expect to see it at day 4.

[2]

(ii) I. State the name of the response of the root to gravity.

[1]

II. Explain why this response is important to the seedling.

[1]

Image 7.1 shows a section through the skin.

Complete labels A and B on Image 7.1.

Image 7.1.

Table 7.2 shows some features of the skin at two air temperatures.

Table 7.2

Using the information in Table 7.2, describe the changes in the skin which occur as the air temperature increases. Explain how each of these changes helps to cool the body

Image 3 shows how the optimum body temperature is maintained.

Image 3

(i) State the name of the mechanism which maintains optimum body temperature.

[1]

(ii) State why it is important that human body temperature remains between 36.5°C and 37.5°C.

[1]

(iii) Apart from sweating, describe and explain one way the skin would have responded at point A on Image 3 to return the body temperature to its optimum.

[2]

In a school experiment, germinating seeds were pinned to a cork plate (which was not rotating) and left in the dark for 48 hours.

The result of the experiment is shown in Image 4.1.

Image 4.1

State the name of the:

(i) growth response shown by the germinating roots in Image 4.1;

[1]

(ii) hormone which controls growth responses in plants.

[1]

A second experiment was set up where germinating seeds were pinned to a cork plate which rotated three times per hour. The apparatus was left in the dark for 48 hours.

The result of the experiment is shown in Image 4.2.

Image 4.2

Explain the growth of the roots in the result shown in Image 4.2.

Suggest why the apparatus was kept in the dark for 48 hours.

Complete the sentence by selecting your answers from the words below.

The central nervous system consists of the ........................................................... and the ..................................................... .

Image 3.1 shows a section through the human eye.

Image 3.1

(i) Label parts A and B on Image 3.1.

[2]

(ii) Using some labels from Image 3.1, complete Table 3.2 by stating the parts of the eye which match the functions.

[3]

Table 3.2

(iii) Joanna leaves a dark room and goes out into bright sunlight.

Explain how parts C and D in Image 3.1 change in order to control how much light enters her eyes when she goes into bright sunlight.

[3]

Complete the following description of Type 2 diabetes by filling in the missing words.

In Type 2 diabetes, body cells do not respond to the hormone ....................................... which is produced by the ................................................. and so the level of ............................................. in the blood becomes too high.

Researchers in Spain stated the following hypothesis.

‘Drinking coffee reduces the risk of having Type 2 diabetes, high blood pressure and obesity.’

• Scientists working for a large chain of coffee shops carried out an investigation to test this hypothesis.

• They used 2000 volunteers, 1000 of whom drank coffee every day and the other 1000 who never drank coffee.

• They recorded the number of volunteers from each group who had Type 2 diabetes, had high blood pressure or were obese.

The results of the investigation are shown in Table 5.1.

Table 5.1

(i) Complete the bar chart in Graph 5.2 by:

[4]

I. adding a scale for numbers of volunteers.
II. drawing bars of the results for high blood pressure and obesity.
III. labelling your bars.

Graph 5.2

(ii) The scientists concluded that the hypothesis was only partly supported. Give the reasons for this conclusion.

[2]

(iii) State one way in which the scientists should have ensured that the investigation was a fair test.

[1]

(iv) A doctor said that she did not have confidence in the results because the investigation was biased.

Give one reason to support this point of view.

[1]

In 2019 the cost to NHS Wales of medical treatments for Type 2 diabetes was £500 million.

Suggest one lifestyle change which individuals can make to reduce the risk of developing Type 2 diabetes.

Image 4.1 shows a reflex arc.

(i) Label A–D on Image 4.1.

[4]

(ii) State two properties of reflex actions.

[1]

(iii) The length of neurone B is 0.9m. An electrical impulse can travel along a neurone at 75m/s.

Use the following equation:

to calculate the time taken for the impulse to travel the length of neurone B.

[2]

Time = ...............................................s

Motor neurone disease prevents motor neurones functioning effectively. Explain why individuals with the disease find it difficult to walk.

Image 9.1 shows a section through human skin.

Image 9.1

On Image 9.1, draw labelled arrows to name and identify:

(i) the structure where sweat is produced;

[1]

(ii) a structure which transports blood.

[1]

Gareth carried out an experiment to investigate homeostasis. He sat in a room heated to 50°C. His internal body temperature, rate of sweating and skin temperature were monitored. After 10 minutes in the room, he drank a glass of ice-cold water. The results are shown in Graph 9.2.

Graph 9.2

Explain the effect that drinking the ice-cold water had on Gareth between 10 minutes and 30 minutes, as shown on Graph 9.2.