3.2

Question 1

state the definition of symbiosis

Answer 1

symbiosis is the intimate co evolved relationship between two members of two different species.

Question 2

Explain parasitism

Answer 2

the parasite benefits in terms of energy and nutrients and host is harmed by loss of these resources. (ticks, fleas, tapeworms)

Question 3

Explain mutualism

Answer 3

Both mutualistic partner species benefit in an inter dependent relationship ( nile crocodile, Egyptian plover)

Question 4

parasites..

Answer 4

parasites have limited metabolism and cannot survive without contact with a host

Question 5

parasite transmissions ; direct contact

Answer 5

direct skin to skin contact. e.g ringworm lice

Question 6

parasite transmission ; resistant stages

Answer 6

allows the parasite to survive in extreme conditions by lying dormant until conditions are optimal e.g spores in fungi/ bacteria.

Question 7

parasite transmission ; vectors

Answer 7

an vector is an organism that carries the parasite from an infected individual and directly infects new hosts. e.g malaria uses the insect vector of a mosquito.

Question 8

secondary hosts

Answer 8

a secondary host is an organism that hosts part of the parasite’s lifecycle and then transfers it indirectly through hosts.

Question 9

secondary host example

Answer 9

parasite - pork tapeworm. primary host - human . secondary host - pig

Question 10

social hierarchy

Answer 10

this is a rank order within groups of animals consisting of dominant and subordinate members. Dominant members carry out ritualistic (threat) displays while subordinate members carry out appeasement behaviour.
E.g pack animals, wolves/hyenas. Gorillas/chickens.

Question 11

benefits of this behaviour ; social behaviour

Answer 11

• reduces conflict
• increases the chance of the dominant’s favourable
  genes being passed onto offspring.
• form alliances to increase social status in groups.

Question 12

cooperative hunting

Answer 12

animals that hunt together in groups. E.g lions/wolves

Question 13

benefits of this behaviour ; cooperative hunting

Answer 13

• subordinate animals benefit as well as dominant
  animals.
• may gain more food then foraging alone.
• larger prey can be hunted.
• increases chance of hunting success.
• less energy is used per individual.

Question 14

social Defence

Answer 14

groups that act together to defend or raise alarm.

E.g flocks of birds, herd animals (bisons).

Question 15

benefits of this behaviour ; social defence

Answer 15

• increases the chance of survival as some individuals
  can watch for predators while others can footage.
  E.g meerkats.
• groups adopt specialised formations when under
  attack to protect their young.

Question 16

Define Altruism

Answer 16

Altruism is behaviour that harms the donor individual but benefits the recipient.
E.g donating food to the recipient.

Question 17

Define reciprocal altruism

Answer 17

reciprocal altruism is when when the roles of donor and recipient later reverse. often occurs in social animals.
E.g vampire bats exchanging blood meals.

Question 18

Kin selection and altruism

Answer 18

Behaviour that appears altruistic (often isnt) can be common between a donor and recipient if they are related (kin).
The Donor does benefit in kin selection, in terms of genetics, as this behaviour between related animals increases the chances of survival of shared genes in the recipient’s future offspring.

Question 19

social insects examples and roles within colonies

Answer 19

examples; bees, wasps, ants, termites.

Roles Within Colonies;
- raise related offspring
- defending the hive
- collecting pollen and nectar
- waggle dances to show direction of food
- the role of male bee drones it to fertilise the queen’s e
egg

Question 20

how sterile workers increase the survival of shared genes in social insects

Answer 20

most members of the colony are related sterile workers who cooperate with other close relatives to raise closely related offspring and in doing so increase the survival of shared genes.

Question 21

primate behaviour

Answer 21

primates often live in social groups and have complex behaviours to prevent conflict

Question 22

complex social behaviours ; grooming, facial expressions , body posture and sexual presentation

Answer 22

• These behaviours support the social hierarchy and
  reduce conflict.
• This reduces conflict through ritualistic displays and
  appeasement behaviour.
• Alliances form between individuals which are used to
  increase social status within the group.