Biology 0610 · IGCSE · Chemical digestion

Chemical digestion — practice question

Gastric juice is released by cells in the stomach lining, and it contains hydrochloric acid and pepsin.
(a(i))[2]

State two functions of hydrochloric acid in the stomach.

(a(ii))[2]

Describe what pepsin does.

(b)[2]

Define what is meant by assimilation.

(c)[2]

Stem cells are present in the epithelial tissue that makes up the stomach lining. Explain why these stem cells are needed.

(d)[2]

The epithelial cells in the small intestine have many microvilli. State what the microvilli do.

(e)[3]

Calculate the percentage increase in the average number of bacteria attached to epithelial cells from 45 minutes to 75 minutes. Give your answer to the nearest whole number.

Worked solution & mark scheme

This 13-mark question has a full step-by-step worked solution and mark scheme. One marking point: Creates a suitable / optimum pH for enzyme activity

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