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
11
What is the primary energy source for nearly all ecosystems on Earth?
Answer:
The Sun
Photosynthesis captures solar energy and converts it into the chemical energy that powers the entire food web. Rare exceptions include deep-sea vent ecosystems powered by chemosynthesis.
12
Which of the following is 'Intraspecific Competition'?
Answer:
Two squirrels of the same species fighting over an acorn.
Intraspecific competition (within a species) is usually more intense than interspecific competition because members of the same species have identical resource requirements.
13
What is a 'population'?
Answer:
All the members of one species in a specific area.
A population is a subset of a community, focusing on individuals of the same species that can potentially interbreed.
14
Which nutrient cycle is almost entirely 'biological' and 'atmospheric'?
Answer:
Both B and C
Both nitrogen and carbon have major reservoirs in the atmosphere and are moved through ecosystems primarily by biological processes (photosynthesis, respiration, fixation).
15
What is 'Ecological Succession' starting from an abandoned parking lot an example of?
Answer:
Primary Succession
If there is no soil (as on bare asphalt), it is considered primary succession. If the asphalt is removed and the original soil is exposed, it would be secondary succession.
16
What is the 'Photic Zone' in an ocean?
Answer:
The upper layer where there is enough light for photosynthesis.
The photic zone is where almost all marine primary production occurs. Most marine life is concentrated in this well-lit upper layer.
17
Which of the following is a 'secondary consumer'?
Answer:
A bird eating a grasshopper.
Secondary consumers are carnivores that eat primary consumers (herbivores). The hawk in this example would be a tertiary consumer.
18
What is 'Nitrogen Fixation' primarily done by?
Answer:
Bacteria and lighting.
Bacteria are the main fixers of nitrogen. Lightning also has enough energy to break the atmospheric $N_2$ bonds, allowing nitrogen to combine with oxygen to form nitrates.
19
Which biome is characterized by 'Succulent' plants like cacti?
Answer:
Desert
Succulent plants are adapted to arid environments. They store water in their fleshy stems or leaves and often have spines to protect their water reserves from animals.
20
What is 'Bioaccumulation'?
Answer:
The buildup of a substance (like a toxin) in an individual organism over its lifetime.
Bioaccumulation happens within a single individual. Biomagnification refers to the increase in concentration as you move up the food chain.