6.3 Flashcards Preview

Biology > 6.3 > Flashcards

Flashcards in 6.3 Deck (10)
Loading flashcards...
1
Q

What is primary defence?

A

Pores, hair, follicles, sebaceous glands, oils—-> reduce pH, inhibit growth of bacteria

2
Q

What is the purpose of mucous membranes?

A

Protect open passages

3
Q

What happens in blood clotting?

A

Platelets release thrombin which causes reaction where fibrinogen becomes fibrin and produces a scab

4
Q

What are phagocytes?

A

Leukocytes that engulf pathogen and contain enzymes which kill them

5
Q

What is an antigen?

A

A foreign substance which triggers the production of antibodies

6
Q

What is the function of lymphocytes

A

Produce antibodies specific to pathogens, which attach to antigens and signal phagocytes. Antibodies remembered in memory cells.

7
Q

How do antibiotics kill bacteria?

A

Interfere with synthesis of bacterial cell wall, so the plasma membrane is exposed to excessive uptake of water and bursts.

8
Q

What is HIV?

A

A tiny virus- 2 strands of RNA, enclosed in a protein coat. Retrovirus, so copies DNA of infected cells by reverse transcription

9
Q

What are t helper cells?

A

Recognise antigens and trigger production of antibodies, macrophages and killer T cells

10
Q

What does HIV do?

A

Destroys T helper cells, causing a loss of antibodies and thus immunity