B 4.1

What is a habitat?

The geographic location + type of ecosystem where an organism lives.

What determines a habitat?

Abiotic factors and the organism’s range of tolerance.

What abiotic challenges do sand dune plants face?

Low water, high salt, sand accumulation.

How does a waxy cuticle help dune grasses?

How does a waxy cuticle help dune grasses?

Why are stomata in pits useful?

They retain moist air and reduce water loss.

Why do dune grasses have rolled leaves?

Reduce wind exposure.

What do rhizomes do in sand dunes?

Grow upward if buried by sand.

Why do roots contain fructans?

Increase osmosis in root tissue.

What challenges do mangrove trees face?

Waterlogged, anaerobic soil + high salt.

What do salt‑excreting glands do?

Remove excess salt.

Why are mangrove roots coated in cork?

Prevent salt absorption.

Why do mangrove roots grow near the surface?

To access oxygen.

What are vertical root branches for?

Oxygen absorption.

Why do mangrove roots have high mineral content?

Increase osmosis in root tissue.

What determines animal distribution?

Water availability + temperature.

What determines plant distribution?

Temperature, water, light, soil pH, salinity, nutrients.

What is a range of tolerance?

The range of a factor an organism can survive in.

What tool helps measure tolerance ranges?

A transect.

What depth do coral reefs require?

Less than 50 m.

What pH do coral reefs need?

Above 7.8.

What salinity do coral reefs need?

32–42 ppt.

Why must water be clear for coral reefs?

Light penetration.

What temperature do coral reefs need?

23–29°C.

What is a biome?

A group of similar ecosystems with similar abiotic conditions.

What drives biome distribution?

Temperature + rainfall.

What is convergent evolution?

Different species evolving similar traits due to similar challenges.

What plant adaptations does the saguaro cactus have?

Fat stems, spines, waxy cuticle, wide roots, CAM metabolism.

What animal adaptations does the fennec fox have?

Nocturnal, long ears, paw hair, light fur, temperature‑moderating coat.

What conditions define tropical rainforests?

High temperature, high precipitation, high light.

What adaptations does the meranti tree have?

Grows 100+ m, smooth trunk, pointed leaves, year‑round photosynthesis.

What adaptations does the spider monkey have?

Long limbs, flexible shoulders, long tail, year‑round breeding.