M3.2 Case Studies

Question 1

Types of adaptation

Answer 1

• Structural: physical feature (e.g. pneumatophores in mangroves help obtain oxygen from the air)
• Physiological: body process (e.g. polar bony fish have antifreeze protein in their blood which prevents their blood from freezing in cold water)
• Behavioural: a behavioural response (e.g. male bower birds decorate their nest with blue items to attract a mate)

Question 2

Banskias reproductive adaptation

Answer 2

Flowers are grouped together in an inflorescence to make them easy for pollinators to find. Flowers also drip nectar to attract birds and insects.

Male part matures before the female part and is carried off by pollinators. This prevents self-fertilisation in individual plants, increasing genetic diversity.

Question 3

Gastric-brooding frog

Answer 3

Female frog eats ~25 fertilised eggs, allowing them to develop into tadpoles in her stomach. Tadpoles and small frogs are let out to feed in ponds, but mother swallows them up again if danger is present. This helps protect the young from predation.

Hormones suppress normal digestive mechanisms and the desire to eat in the mother during pregnancy → allows young to develop in the stomach.

Question 4

Red kangaroos

Answer 4

Behavioural:
- Heat: lick forearms so blood can cool; panting
- Water: only sweats when it is hopping; obtain water from food

Physiological:
- Water: concentrated urine

Reproductive adaptation (behavioural)
- Embryonic diapause: 1 young-at-foot, 1 young-in-pouch, 1 dormant embryo in uterus