B4.1 adaptation to environment (year 6)

Question 1

2 examples of an organism adapted to its habitat

Answer 1

sea oat:
- species of grass that lives on sand dunes
- drought resistant
- shallow, dense, interwoven root system to maximise take-up of water as sand does not hold water for very long + the intertwined roots help to hold sand in place and prevent erosion
- narrow leaves to reduce transpiration, close stomata if soil/sand conditions around roots remain dry for extended periods of time
- produce nodes and rhizomes near their base. These asexual growth shoots are stimulated when covered by sand and produce shoots above the sand.

Red Mangrove tree:
- prop roots extend above the water line
- the roots above water level can absorb air, used to oxygenate root tissues below water line buried in the mud
- roots below water line filter salt out of water for fresh water
- tangled root growth provides a habitat for many fish
- adapated to changing water levels characteristic of saltwater tides
- produce propagule, which floats in water with its roots downwards for seed dispersal

Question 2

Examples of abiotic variables affecting species distribution

Answer 2

• water availability
• temp +pH range
• light intensity and duration
• salinity
• soil composition

Question 3

Conditions required for coral reef formation

Answer 3

Corals are the result of a symbiotic r/s btwn coral polyps and an algae ZOOXANTHELLAE:

• Water depth (zooxanthellae require adequate light levels and light only penetrates to relatively shallow depths)
• Water temp (corals survive in a narrow range of temp. When water becomes too warm (e.g. due to global warming) the corals become stressed and expel zooxanthellae, becoming bleached)
• Salinity
• Water clarity
• water pH (increased CO2 from fossil fuel emissions results in lower pH that is detreimental to coral growth. This acidification results in less CaCO3 compounds being avaliable in water for corals to use when building reefs)

Question 4

Practice drawing a graph showing the distribution of diff biomes with climatic variables as the x and y axis

Answer 4

Pearson biology page 354

Question 5

Examples of adaptations to hot deserts

Answer 5

SAGUARO CACTUS:
- thick waxy skin that is waterproof for water retention
- covered in bristles as defence against grazers
- has a single long taproot that grows downwards to retreive deep water when avaliable, but also has a massive shallow root system to absorb occasional rainwater.
- water is stored in sponge-like tissue

FENNEC FOX:
- large vascular ears to dissipate heat and locate small prey moving underground
- kidneys adapted to reabsorb most of the water passing through them
- rarely urinate

Question 6

Examples of adaptations to tropical rainforest biome

Answer 6

KAPOK TREE:
- has a strong foundation from buttress roots that extend below ground to support rapid growth and a very tall trunk in relatively shalllow soil.
- this strong foundation allows the tree to grow very tall = more sunlight

POISON-DART FROGS:
- highly toxic chemicals in their skin as a result of their diet of poisonous insects as defence against predators
- evolved to have very bright colours and body patterns as warning to predators (warning coloration)