IB myp 4-5 Biology – Practice Questions- All Topics
Topic :Organsims-Classification
Topic :Organisms– Weightage : 21 %
All Questions for Topic : Habitat,Ecosystem,Inter dependency,Unity and diversity in life forms,Energy transfer and cycles,Classification
Question:
Discuss whether nutrients such as amino acids have a function in cells or are merely needed.
▶️Answer/Explanation
Ans: Debatable – depends on meaning of ‘function’; amino acids are naturally occurring substances; which living organisms use to provide a range of chemical properties in proteins.
Question:
The keystone of a bridge is a wedge-shaped stone at the summit of an arch that locks the whole structure together.
a) What is a keystone species in an ecosystem?
▶️Answer/Explanation
Ans: Species without which major changes would occur in an ecosystem; to both biotic and abiotic factors; species on which many other species depend.
b) Which are keystone species in the examples described here?
▶️Answer/Explanation
Ans: Prairie dogs; sea otters; acorn banksia.
c) What is the reason for trying to identify keystone species in natural ecosystems?
▶️Answer/Explanation
Ans: Because their conservation is vital to the sustainability of the ecosystem; conservation efforts should be concentrated on keystone species.