B4.1 - biomes and adaptations (5o)

Question 1

what is coral?

Answer 1

corals form due to the symbiotic relationship between coral polyps and photosynthetic algae called zooxanthallaes

Question 2

what is the distribution of coral reefs?

Answer 2

coral reefs are found in less than 1% of the ocean’s surface area, indicating that a specific combination of abiotic factors are required for their formation

Question 3

what are the conditions required for coral reef formation?

Answer 3

• • shallow water depth = required to provide photosynthetic zooxanthallae with sunlight because this can only penetrate water to relatively shallow depths.
• neutral pH = provides sufficient calcium carbonate compounds to make coral polyps, avoiding bleaching.
• correct salinity = maintains equilibrium between coral cells and the surrounding.
• freshwater run-off, such as from rivers, can form areas of ocean where salinity is too low for coral formation.
• clarity = water free from sediment or pollution is required to support light penetration.
• temperature between 20 and 28 = maintains a functioning relationship between polyps and zooxanthallae and to avoid bleaching

Question 4

how are abiotic factors determinants of terrestial biome distribution?

Answer 4

for any given temperature and rainfall pattern, one natural ecosystem type is likely to develop

Question 5

why do ecosystems within a biome have similar communities?

Answer 5

• ecosystems within a biome share similar abiotic conditions, which causes similar communities to develop
• populations within ecosystems of the same biome therefore experience similar selection pressures, leading to convergent evolution through natural selection

Question 6

what is a biome?

Answer 6

a biome is a group of ecosystems with similar communities

Question 7

what is the difference between biomes and ecosystems?

Answer 7

unlike an ecosystem, all organisms are not interacting with each other in a biome

Question 8

what are the climate conditions and communities present in a tropical forest?

Answer 8

climate conditions:
- warm (20 - 25)
- high annual rainfall
- nutrient-poor soil (as plants are not deciduous)

communities:
- very high biodiversity of animals and plants

Question 9

what are the climate conditions and communities present in a temperate forest?

Answer 9

climate conditions:
- 4 seasons and no extreme temperature
- 750 - 1500 mm of rain per year
- leaf drop and decay enrich soil nutrients

communities:
- deciduous broad-leaved trees dominate
- rich variety of animal species

Question 10

what are the climate conditions and communities present in a taiga?

Answer 10

climate conditions:
- range of -42 to 20 degrees with very cold winters
- 300 - 900 mm of rain per year

communities:
- dominated by conifer trees
- animals are adapted to a very cold climate

Question 11

what are the climate conditions and communities present in a grassland?

Answer 11

climate conditions:
- temperature varies with latitude (-25 - 30)
- semis -arid (500 - 900 mm of rain per year) with possible seasons

communities:
- grass species dominate vegetation
- no trees due to a lack of water
- animal species are dominated by grazers and a few of their predators

Question 12

what are the climate conditions and communities present in a tundra?

Answer 12

climate conditions:
- cold (-40 - 18)
- low precipitation (150 - 250 mm per year)
- long dark periods in the winter

communities:
- no trees due to a lack of water and short growing season
- soil is mostly frozen
- animals migrate or hibernate

Question 13

What are the climate conditions and communities present in a hot desert?

Answer 13

climate conditions:
- hot temperatures during the day
- very low annual rainfall (<300mm)

communities:
- sparse vegetation
- plants often have spines for leaves
- animals often burrow and are only active during cooler nights

Question 14

why do similar communities occur in the same type of biome even if 2 areas are geographically separated?

Answer 14

convergent evolution
- this leads to organisms having similar analogous structures, which are similar in function, but have different genetic origins

Question 15

how is the cactus adapted to life in hot deserts?

Answer 15

• thick waxy cuticle = reduces water loss by evaporation
• leaves covered in bristles = a defense against grazing
• a long taproot = to retrieve deep water
• large shallow root system = to absorb the occasional rain water efficiently
• stores water in the stems = to maintain water supply for the dry periods

Question 16

how is the fennel fox adapted to life in hot deserts?

Answer 16

• large ears that are highly vascularised = helps to dissipate heat
• large ears = assist predation by locating small animals moving underground
• long hoop of Henle in the kidney and rarely urinates = aids water conservation

Question 17

how is the kapok tree adapted to life in tropical rainforests?

Answer 17

• grows quickly and very tall = to successfully compete for sunlight in the upper canopy
• buttress roots that extend above ground = to support rapid growth and a tall tree, within the shallow soil

Question 18

how is the poison dart frog adapted to life in tropical rainforests?

Answer 18

• highly toxic chemicals in the skin (from eating toxic insects) = to kill potential predators
• warning colouration = to reduce predation
• use bromeliad plants as the location of small pools of water within the canopy = into which the eggs are laid