General Science/Everyday Science MCQs
Topic Notes: General Science/Everyday Science
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
41
What is 'Ecological Efficiency'?
Answer:
The percentage of energy transferred from one trophic level to the next.
This efficiency is typically low (around 10%). It is the reason why food chains rarely have more than 4 or 5 levels; eventually, there isn't enough energy left to support another level.
42
In the phosphorus cycle, how do animals obtain phosphorus?
Answer:
By eating plants or other animals.
Animals get the phosphorus they need for DNA and ATP by consuming organic matter. When they die or excrete waste, decomposers return the phosphorus to the soil.
43
Which of the following is true about 'Inverted Pyramids of Numbers'?
Answer:
They can occur when one large producer (like a tree) supports many smaller consumers (like insects).
A single oak tree (one producer) can support thousands of herbivorous insects. In this case, the 'pyramid' of individual numbers would have a very small base.
44
What is a 'Trophic Level'?
Answer:
The position an organism occupies in a food chain.
Organisms are grouped into trophic levels based on their source of energy. Level 1 are producers, Level 2 are primary consumers, and so on.
45
Which of the following is a 'provisioning' ecosystem service?
Answer:
Timber and food production
Provisioning services are the products obtained from ecosystems, such as food, fresh water, wood, fiber, and genetic resources.
46
What is the 'Biosphere'?
Answer:
The sum of all the planet's ecosystems.
The biosphere extends from the deepest ocean trenches to several kilometers into the atmosphere, encompassing every place on Earth where life exists.
47
Which biome has the lowest annual precipitation?
Answer:
Desert
Deserts receive less than 25 cm of rain per year. Evaporation often exceeds precipitation, requiring plants and animals to have extreme adaptations for water conservation.
48
What is 'Nitrogen Saturation'?
Answer:
When an ecosystem can no longer process the amount of nitrogen entering it, leading to nutrient leaching.
Excess nitrogen from pollution or over-fertilization can overwhelm a forest's capacity to use it, causing nitrogen to wash into waterways and acidified soil.
49
Which of the following is the 'Limiting Factor' for primary productivity in the deep ocean?
Answer:
Light
Photosynthesis can only occur in the photic zone. Below a few hundred meters, light is insufficient, so productivity is limited despite the abundance of water and other nutrients.
50
What is 'Mimicry' in ecology?
Answer:
When a species evolves to look like another species for protection.
Batesian mimicry is when a harmless species looks like a harmful one. Mullerian mimicry is when two harmful species evolve to look like each other to reinforce predator avoidance.