IB myp 4-5 Biology – Practice Questions- All Topics
Topic :Human interactions with environments-Habitat Change or destruction
Topic :Human interactions with environments– Weightage : 21 %
All Questions for Topic : Human influences,Habitat Change or destruction,Pollution/Conservation,Over Exploitation,Mitigation of adverse effects
Question
Changes in population size of living organisms are dependent on biotic and abiotic factors. For plants, this includes sunlight, temperature and the availability of nutrients.
Select the correct category for each of the following factors.
▶️Answer/Explanation
Ans:
Biotic: fungi and microbes
and
Abiotic: water
Question
(c )At the end of the Cretaceous period an asteroid impact resulted in rapid global cooling and falling ocean levels. Suggest two traits that helped mammals to survive in the new environmental conditions.
Being endothermic animals, they were warm blooded. This helped the mammals stay warm. Another factor was the presence of fur. This would cover the body and protect it from cold, harsh weather.
▶️Answer/Explanation
Ans:
Any two points, for example (2 max):
- fur (for warmth)
- insulating layer (for warmth)
- warm-blooded (control their temperature)
- carry their young or high level of parental care or give birth to live young
- mothers feed their young
Question
(d )Rabbits are an example of a species that has different colours of fur. In a population of mountain rabbits, rabbits with white fur are far more common in the snowy upper areas of the mountain. Rabbits with darker fur are far more common at lower levels. The mixed coloured rabbits are found in height ranges overlapping the others.
Use the theory of natural selection to explain this distribution of rabbits with different coloured
The natural theory of selection states that animals with the features that are best suited to survive to the environment, will survive. Since they have these favourable genes, they can pass them down to their descendants, and thanks to gene inheritance, these descendants will also have these favourable genes. For example if there are black and white rabbits on a mountain, the white rabbits will camouflage from their predators much more easily. The black rabbits will be preyed upon much more often resulting in their decline, while the white rabbits that survive will pass on their genes to their children. Eventually the black rabbits fade out and leave behind the white rabbits.
▶️Answer/Explanation
Ans:
Any four of the following points (4 max):
- rabbits are more likely to survive when fur colour matches location (as they are notfound easily by predators)
- longer survival means greater chance of reproduction
- concentration of fur types by location means breeding more likely between similartypes
- offspring are more likely to have advantageous fur colour
- offspring born with disadvantageous fur type less likely to survive