KEY AREA 3-5 REVISION

• A

• B

• C

• D

Answer explanation

HIGH SEED OUTPUT, SORT LIFE CYCLE ARE PROPERTIES OF ANNUAL WEEDS.

VEGATATIVE REPRODUCTION AND STORAGE ORGANS ARE PROPERTIES OF PERENNIAL WEEDS

Name the type of symbiotic relationship described.

Justify your answer.

Answer explanation

MUTUALISM

Justification: both species benefit: the clownfish is protected from predators by the anemones tentacles, the clownfish drives away predators of the anemone.

Mites (D. gallinae) and chickens have a symbiotic relationship in which

the mites feed on the chicken’s blood.

Name this type of symbiotic relationship.

Answer explanation

PARASITIC/PARASITISM

not just the word "parasite"

Mites (D. gallinae) and chickens have a symbiotic relationship in which

the mites feed on the chicken’s blood.

State the term used to describe the chicken in this relationship.

Answer explanation

The chicken is the HOST

Intensively farmed chickens show abnormally low levels of activity.

State the term used to describe this behaviour

Answer explanation

low levels of activity id known as APATHY.

(high levels of activity = HYSTERIA)

State an advantage to humans of intensive farming.

Answer explanation

Intensive farming benefits:

Low cost/cost effective/less land

use/high profits

Adult beef tapeworms live in the intestine of humans. Segments of the adult worm are

released in the faeces. Embryos that develop from them remain viable for five months. The embryos may be eaten by cattle and develop in their muscle tissue.

Which row in the table identifies the roles of the human, tapeworm embryo and cattle?

• A

• B

• C

• D

Answer explanation

It tells us the tapeworms live in the human intestines, so they are the hosts.

It then tells us that Embryos that develop from them remain viable for five months, these are released to allow the parasite to survive the adverse conditions - this is resistant stages

The embryos are THEN eaten by cows, making them the secondary host

• 2 only

• 3 only

• 1 and 2 only

• 2 and 3 only

Answer explanation

statement 3 describes a PARASITIC relationship

Use the information given to suggest why ticks can be described as:

1. 1. vectors

2. 2. parasites

Answer explanation

Explain why Schistosoma mansoni is described as a parasite.

Answer explanation

Schistosoma mansoni BENEFITS as it gains energy/nutrients AND the host is HARMED by loss of these nutrients/energy