Fill in the table about receptors. The first answer has been done for you.

Transcription

1 Ass.B1.2H Q1 (a) Fill in the table about receptors. The first answer has been done for you. RECEPTORS IN THE Eyes SENSITIVE TO Light Skin Sound Tongue (3) (b) Describe, in as much detail as you can, how information is transmitted from light receptors in the retina to the brain.....

2 (3) (Total 6 marks) Q2. The diagram shows the nervous pathway used to coordinate the knee-jerk reflex. When the person is hit at point P, the lower leg is suddenly raised. (a) Name neurones A, B and C. A... B... C...

3 (3) (b) The receptor in the muscle in the leg is sensitive to a stimulus. Suggest the stimulus.... (1) (c) Describe what happens at the synapse during this reflex

4 (3) (Total 7 marks) Q3. (a) Some students are investigating the behaviour of a mouse. They use a large empty box. The box has squares marked on the floor, as shown in the diagram. (C = corner square, S = side square, I = inside square) C 1 S 1 S 2 S 3 C 2 S 10 I 1 I 2 I 3 S 4 S 9 I 6 I 5 I 4 S 5 C 4 S s S 7 S 6 C 3 They put a mouse in the empty box. They record which square the mouse is in every minute for the next 15 minutes. The students then put a dish of food on square I 2 and repeat the observations. They get these results. Time (minutes) Position of mouse in empty box Position of mouse with food on I C 1 C 1 S 2 C 3 C 3 S 9 L 3 C 1 C 1 C 1 S s C 4 C 4 C 1 S 2 C 2 C 2 C 2 S 5 C 3 S 1 C 4 S 1 I 2 I 2 C 1 C 1 C 1 S 10 C 1 (i) Make a table to show how much time the mouse spends in the corner squares (C), the side squares (S) and the inside squares (I) both in the empty box and when food is present.

5 (4) (ii) Present your results as a bar chart. (3) (iii) What do the results show? (2)

6 (Total 9 marks) Q4. The influenza virus damages the cells lining the respiratory tract causing sore throats. Coughing and sneezing spread the virus. (a) Give the correct term for this method of spreading an infection. (1) (b) In an immunisation programme such as that for MMR (Measles, Mumps and Rubella), suggest why it is essential for a large proportion of the child population to be vaccinated in order to protect the few individuals who are unable to be vaccinated.

7 (1) (c) In some modern influenza vaccines the protein surface sub-units are separated from the virus coat and used for the vaccine. This stimulates an effective immune response in the same way as inactive pathogens. (i) Explain how this immunity is produced in the body following vaccination, and how further illness from the same virus is prevented. (4)

8 (ii) This type of immunity resulting from an influenza injection is described as... immunity. (1) (d) The diagram shows the structure of an influenza virus. Influenza epidemics can arise because the nucleic acid of the virus frequently changes. This results in changes in the virus structure and so a new strain of the virus is formed. A person who has had influenza or who has been vaccinated may not be immune to the new strain. Explain why this is so, using the diagram of the influenza virus structure and your knowledge of immunity.

9 (3) (Total 10 marks) M1. (a) pressure / temperature / hot / cold / touch / pain ear / cochlea chemicals / taste / named taste e.g. salt (reject skin receptors e.g. hot, cold) for 1 mark each 3 (b) impulses / electrical pulse / electrical signal (reject information, message, pulse, signal) via sensory neurones (ignore relay neurone, synapse) (in) optic nerve (allow 1 mark for via nerves or neurone if neither second nor third mark scored, reference to spinal cord disqualified route mark) for 1 mark each

10 3 [6] M2. (a) ignore nerve / neuron(e) throughout A sensory accept afferent 1 B motor accept efferent

11 1 C relay accept intermediate 1 (b) stretch allow pressure / pull / tension (in muscle) allow a hit at (point) P ignore pain 1 (c) any three from: chemical (release) accept neurotransmitter / acetylcholine diffuses (across the gap / synapse) transmits impulse / information (across synapse) allow transmits signal / message between neurones / nerve cells / named if named, must be either sensory / A to relay / C or relay / C to motor / B allow to the next neurone

12 3 [7] M3. (a) (i) counting empty 10, 4, 1 and correctly placed in table counting with food 9, 4, 2 and correctly placed in table table with three columns and correct headings for 1 mark each 4 (ii) reasonable scales plots all correct all labels present for 1 mark each 3

13 (iii) e.g. mouse spends most of its time in the corners whether or not food is present in middle for 1 mark each 2 (b) vibration/sound receptors in ear detect sound impulses/electrical signals to brain for 1 mark each 2 [11] M4. (a) droplet infection or aerosol infection do not accept airborne accept airborne droplets

14 1 (b) so there is no large group which could catch the infection/pass on the infection converse if large numbers can t pass it on the virus is less likely to reach those few who are susceptible 1 (c) (i) any four of the following points:- example of a 3 mark answer: Lymphocytes produce specific antibodies... comment on specificity applied to antibodies or lymphocytes (recognition by) lymphocytes; (white cells) make antibodies; antibodies destroy/neutralise the virus/antigen/protein subunit; do not accept antibodies KILL viruses accept white blood cells replicate accept some white cells form memory cells/live a long time; accept subsequent infection results in very rapid antibody production;

15 max 4 (ii) active; 1 (d) any three of the following points Structure change in: protein for binding to host cell; accept changes in surface proteins (of protein coat) spike containing enzyme; changes in antigen Fit: existing/circulating/old antibodies don t match new virus strain shape/new antigen/new binding protein; Wrong antibodies: injection does not stimulate antibodies against all strains/different antigens; accept wrong antibodies for 1 mark

16 max 3 [10]