SB5i Physical and Chemical Barriers

Question 1

chemical defence

Answer 1

The use of chemical compounds to defend against attacks. Examples include lysozyme and hydrochloric acid.

Question 2

Chlamydia

Answer 2

A bacterium that causes a sexually transmitted infection.

Question 3

ciliated cells

Answer 3

A cell that lines certain tubes in the body and has cilia on its surface.

Question 4

hydrochloric acid

Answer 4

Acid produced by cells lining the stomach, of about pH 2, which destroys many pathogens in food and drink.

Question 5

lysozyme

Answer 5

An enzyme produced in tears, saliva and mucus, which damages pathogens.

Question 6

mucus

Answer 6

A sticky substance secreted by cells that line many openings to the body.

Question 7

physical barrier

Answer 7

A structure that stops something from entering a certain area. For example, the body has physical barriers, such as the skin, that stop microbes from getting inside the body.

Question 8

screening

Answer 8

Tests on samples of body fluids to check if people have a certain condition, e.g. an STI.

Question 9

sexually transmitted infection (STI)

Answer 9

A communicable disease that is passed from an infected person to an uninfected person during sexual activity.