GCSE OCR Gateway Biology Combined Science 5.1 The Human Nervous System: It is important that our body ma

Question

It is important that our body maintains a constant internal environment.

Complete these sentences about maintaining a constant internal environment.

You can use each word once, more than once or not at all.

carbon dioxide
embryonic
hydrogen
insulin
metabolic
oestrogen
oxygen
testosterone

The body needs a constant internal environment so that **metabolic** reactions take place at an appropriate rate.
The body needs to maintain **oxygen** levels so that aerobic respiration can take place.
Blood sugar levels are controlled by the hormone **insulin**.

The nervous system helps the body maintain a constant internal environment. It also allows a person to respond to external stimuli.

A person touches a hot pan. Fig. 11.1 shows the reflex arc involved with a response when a person touches a hot pan.

spinal cord
                                             
                                 ----------------------------------- 
                                        neurone
                                             
                                    Receptors in skin
                                             
                                            muscle
                                             
                                     ----------------------------------- 
                                        neurone

Fig. 11.1

(i) Complete the three boxes in Fig. 11.1 to label the neurones involved in the response.

(ii) Draw two arrows on Fig. 11.1 to show the direction the nerve impulse travels along each neurone in the arm.

(iii) Explain how the reflex arc prevents too much damage from the hot pan.

Caffeine is a chemical found in coffee and cola drinks.

(ii) Fig. 11.2 shows the results.

Key
               ───────────────
                  Mean reaction time before drink

Mean reaction time 10 min after drink

Mean reaction time 20 min after drink

1.0 -----------------------------------------------------
       Reaction time (seconds)
   0.8
   0.6
   0.4

0.2
   0.0

Group A
    caffeine-free drink
         Group B
        caffeine drink

Fig. 11.2

Use data from Fig. 11.2 to describe the effect of caffeine on reaction time.

It is important that our body maintains a constant internal environment - OCR Gateway - GCSE Biology Combined Science - Question 11 - 2021 - Paper 1

Worked Solution & Example Answer:It is important that our body maintains a constant internal environment - OCR Gateway - GCSE Biology Combined Science - Question 11 - 2021 - Paper 1

Complete these sentences about maintaining a constant internal environment.

Complete the three boxes in Fig. 11.1 to label the neurones involved in the response.

Draw two arrows on Fig. 11.1 to show the direction the nerve impulse travels along each neurone in the arm.

Explain how the reflex arc prevents too much damage from the hot pan.

Use data from Fig. 11.2 to describe the effect of caffeine on reaction time.

Join the GCSE students using SimpleStudy...

Other GCSE Biology Combined Science topics to explore