Component 3.3 - Parasites Flashcards Preview

Eduqas A level Biology - Year 1 > Component 3.3 - Parasites > Flashcards

Flashcards in Component 3.3 - Parasites Deck (9)
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1
Q

What is the pork tapeworm’s primary and secondary host?

A

Primary host: human

Secondary host: pig (a larval form)

2
Q

How is the anterior end of the pork tapeworm adapted for survival?

A

It is made of muscle carrying suckers and hooks, attaching it strongly to the duodenum wall.

3
Q

How does the tapeworm prevent itself from being killed by the host’s immune response?

A

1) It has a thick cuticle

2) It can make enzyme inhibitors, preventing the host’s enzymes digesting it.

4
Q

How is the pork tapeworm adapted to obtaining nutrients?

A

1) It has a large surface area to volume ratio so digested food is absorbed over the whole body surface
2) It has a short diffusion pathway so the tapeworm can obtain nutrients quickly
3) It lacks digestive system due to it feeding through its cuticle

5
Q

How does the pork tapeworm increase its chance of transmission and fertilisation?

A

1) Tapeworm is a hermaphrodite, contains both male and female reproductive organs so can self-fertilise
2) Produces a large number of eggs (with resistant shells) that pass out in faeces

6
Q

Describe features of a headlouse?

A

Wingless insects, cannot fly, they have legs poorly adapted to jumping - transferred by direct contact

If removed from the human, on which they live, they die.

7
Q

How does the headlouse feed?

A

By sucking blood from the scalp of the host

7
Q

How are humans infected by the pork tapeworm?

A

When they eat undercooked pork containing live larval forms

8
Q

How is the headlouse adapted to survival?

A

1) It has claws to hold onto hairs

2) Lays eggs which are glued to base hairs

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