- IB DP Biology 2025 SL- IB Style Practice Questions with Answer-Topic Wise-Paper 1
- IB DP Biology 2025 HL- IB Style Practice Questions with Answer-Topic Wise-Paper 1
- IB DP Biology 2025 SL- IB Style Practice Questions with Answer-Topic Wise-Paper 2
- IB DP Biology 2025 HL- IB Style Practice Questions with Answer-Topic Wise-Paper 2
Explain how organisms adapt to the environment.
Habitat is the place in which a community, species, population or organism lives.
Habitat includes:
-the geographical & physical location
-the type of ecosystem in that area.
Things that affect the ecosystem in that area:
-abiotic factors, climate conditions, range of tolerance, special locations
Different organisms have different adaptations within different habitats.
What are abiotic factors that affect biomes?
Abiotic factors that affect biomes are :
-Temperate & rainfall affect distribution of biomes
-Similar ecosystems will arise in those areas, leading to convergent evolution
-Different types of biomes: tropical rainforest, temperate forest, grassland, Mediterranean, desert, tundra, mountain
Lists the climate conditions in different biomes.
Communities look very similar because of convergent evolution
Climate conditions in different biomes are:
1. Tropical forest: high temp, high rainfall
2. Temperate forest: moderate (fluctuating) temp, medium rainfall
3. Taiga (boreal forest): low temp, low/medium rainfall
4. Grassland: fluctuating temp, low rainfall
5. Tundra (cold desert): really low temp, really low rainfall
6. Hot desert: high temp, really low rainfall
What are the adaptations to life in hot deserts & tropical rainforests?
- Adaptations to life in hot deserts are:
1. Hot desert: camel – hump to store fat to use as water
2. Hot desert: desert tortoise – digs burrows, has special facet to dig burrows
3. Hot desert: saguaro tortoise – thick waxy coaxing, reduced leaves, hard spines
- Adaptations to life in tropical rainforests are:
1. Tropical rainforest: tiger – striped coat
2. Tropical rainforest: okapi – dark body, stripes
3. Tropical rainforest: drip tips – climbing plants, aerial roots, pointy leaves to drain excess water
How does abiotic factors affect species distribution?
Abiotic factors affect species distribution as:
Species can survive in certain areas because of abiotic factors.
–ex abiotic factors: temps, pH, salinity, humidity, oxygen levels — causes species to have a limited range of exposure
1. Sugar maple: temp must be between -18 degree C & 27 degree C
2. Tropical fish: temp ranges from 60-80 degree
Explain range of tolerance.
Range of environmental conditions that are survivable for a species
-Range of tolerance acts as a limiting factor of population size
-Shifts outside of that range leads to decreased population size
-Organisms have specific requirements for successful growth, development, & reproduction
-Variation is required in a population for it to act as a selective pressure
Outline coral reefs.
-Coral reefs are very sensitive
-Primary filter feeders & have a symbiotic relationship w/ zooxanthellae
-Requires very specific conditions for formation
1. Temperature: 23-29 degree C; warm-hot
2. Salinity: high salt levels 32-42 parts per thousand
3. Light: clear water for high levels of light; for algae to photosynthesize
4. pH: need a high pH above 8; high pH for skeletal structure & nutrition
5. Water depth: most corals occur within less than 25m of water depth
What are the special locations of abiotic environment? Provide examples.
Special locations of abiotic environment along with examples are:
1. Sand dunes: salty & sandy; grass species can grow in them
ex: American beachgrass – the plant has a deep, strong & extensively creeping rhizome
-Allows it to survive in sandy & salty environments; rhizome is held in place & grown horizontally
-Takes in salty water & can still survive through rhizome
-Has very little competition for space be nothing can survive in sand dunes
2. Mangrove swamps:
ex: Mangroves – coastal intertidal zone
-Many mangrove forest can be recognized by their dense tangle of prop roots that make the trees appear to be standing on stilts above the water
-The tangle of roots allows the trees to handle the daily rise & fall of tides, which means that most mangroves get flooded at least twice per day
-The roots also slow the movement of tidal waters, causing sediments to settle out of the water & build up the muddy bottom
-Very few organisms can survive in coastal intertidal zone, so most of the things that can aren’t going to damage the Mangrove’s roots, since they’re going to eat what the Mangrove produces, not their roots
-Roots gets damaged by water, which is why there’s so many — when one gets damaged, they can still survive