Which structure in the motor neuron is required for saltatory conduction?

[Source: https://commons.wikimedia.org/wiki/File:Anatomy_and_physiology_of_animals_Motor_neuron.jpg]

C

Pressure changes inside the thorax cause the movement of air in and out of the lung alveoli during ventilation. Alveolar pressure correlates to thoracic pressure. The diagram shows pressure changes in lung alveoli during ventilation in relation to normal atmospheric pressure. What causes forced movement of air out of the lungs at T?

B

The diagram shows the human heart.

Which shows the sequence of blood flow in the heart?

A. III IV I

B. IV III II

C. VII VIII I

D. VIII VII VI

C

The light micrograph shows two blood vessels, an artery and a vein, in transverse section.

[Source: Columbia Center for New Media Teaching and Learning, n.d. Epithelium: Simple Squamous Epithelium. [image online] Available at: http://www.columbia.edu/itc/hs/medical/sbpm_histology_old/lab/lab02_squamous.html [Accessed 29 November 2019].]

What explains the different shapes of these blood vessels?

A. Arteries do not have valves.

B. Muscle cells are found only in the walls of veins.

C. Arteries have a larger lumen-to-wall thickness ratio.

D. There are fewer elastic fibres in the walls of veins.

D

Very few candidates answered this correctly with many incorrectly answering C, that arteries have a larger lumen-to-wall thickness ratio than veins. The question was taken from 6.2 Identification of blood vessels as arteries, capillaries or veins from the structure of their walls.

The graph shows the amounts of two substances present in food ingested by a healthy person as it moves along the gut.

Which substances could X and Y be?

D

This question had the second highest discrimination index on the examination paper.

What is the role of type II pneumocytes?

A. To carry out gas exchange

B. To keep the alveoli moist

C. To increase surface tension

D. To maintain partial pressures of gases

B

Which hormone is matched with its site of production and its role?

D

On the graph, which curve represents the change in FSH levels during the menstrual cycle?

D

What is a method of transmission of HIV and its effect on the immune system?

A

Which structures are part of the walls of both capillaries and veins?

I. Cells

II. Pores

III. Elastic fibres

A. I only

B. I and II

C. I and III

D. I, II and III

A

This was another question where fewer candidates answered correctly than the guess-level of 25%. The most popular choice had elastic fibres as a feature of both capillaries and veins. This indicates that many candidates' knowledge of the structure of blood vessels was weak.

The diagram shows some of the organs associated with the digestion of starch. Which organ produces amylase?

[Source: Cancer Research UK. Diagram showing the parts of the digestive system. 30 July 2014. Available at: https://
commons.wikimedia.org/wiki/File:Diagram_showing_the_parts_of_the_digestive_system_CRUK_324.svg.
This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
https://creativecommons.org/licenses/by-sa/4.0/deed.en [Accessed 2 December 2021]. Adapted.]

D