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
51
Which biome is characterized by 'spiny' shrubs, mild rainy winters, and long dry summers?
Answer:
Chaparral
The chaparral (Mediterranean biome) is found in coastal areas. Its plants are fire-adapted and have small, tough leaves to conserve water during the dry season.
52
What is the primary role of 'fungi' in the carbon cycle?
Answer:
Releasing $CO_2$ through the decomposition of wood and organic matter.
Fungi are master decomposers, especially of complex materials like lignin and cellulose. By breaking these down, they release carbon back into the atmosphere as $CO_2$ through respiration.
53
Which of the following is a result of 'Top-Down' control (Trophic Cascade)?
Answer:
The removal of wolves leads to overpopulation of elk and the destruction of riverside vegetation.
Top-down control occurs when changes in a top predator population 'cascade' down through multiple trophic levels, often having unexpected effects on the producers.
54
Which aquatic zone is found at the very bottom of a body of water?
Answer:
Benthic zone
The benthic zone includes the sediment surface and sub-surface layers. Organisms living here are called 'benthos' and often rely on organic matter that sinks from above.
55
Which process converts nitrates into nitrogen gas?
Answer:
Denitrification
This occurs in oxygen-poor environments where bacteria use nitrates instead of oxygen for respiration, releasing $N_2$ gas back to the atmosphere.
56
What is 'net primary productivity' (NPP)?
Answer:
The energy left over for consumers after plants have used what they need for respiration.
NPP is the actual rate at which biomass is accumulated in an ecosystem. It represents the chemical energy available to all heterotrophs (consumers and decomposers).
57
Which of the following is an example of 'cryptic coloration'?
Answer:
A walking stick insect that looks like a twig.
Cryptic coloration is a form of camouflage. It allows an organism to blend into its background, making it difficult for predators (or prey) to spot it.
58
What is 'bottom-up' control in an ecosystem?
Answer:
When the availability of nutrients or producers limits the higher trophic levels.
In a bottom-up model, the productivity of the entire ecosystem is determined by the supply of nutrients and the success of the primary producers.
59
Which biome is characterized by broad-leaved trees that lose their leaves in the winter?
Answer:
Temperate Deciduous Forest
Deciduous trees shed their leaves as an adaptation to survive the cold, dry winter months when water is frozen and photosynthesis is difficult.
60
What is 'resource partitioning'?
Answer:
When similar species evolve to use different parts of a resource to avoid competition.
Resource partitioning allows similar species to coexist. For example, different species of warbler birds might feed in different parts of the same tree (top vs. bottom) to reduce direct competition.