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
1
Which cells provide the grittiness in pears?
Answer:
Sclereids
Sclereids are short sclerenchyma cells with very thick walls.
2
Which type of plant growth increases the girth of the stem?
Answer:
Secondary growth
Secondary growth results from the activity of lateral meristems.
3
The 'pericycle' is found in:
Answer:
Roots
The pericycle is the outermost layer of the vascular cylinder in roots.
4
Which hormone is involved in 'phototropism'?
Answer:
Auxin
Auxin accumulates on the shaded side of a stem, causing it to bend toward the light.
5
What is the primary function of 'stomata'?
Answer:
Gas exchange and transpiration control
Stomata allow the entry of CO2 for photosynthesis and the exit of water vapor during transpiration.
6
Which tissue provides the most flexible support to a growing plant?
Answer:
Collenchyma
Collenchyma cells have thick primary walls that can stretch as the plant grows.
7
What is the 'symplast'?
Answer:
The continuum of cytoplasm connected by plasmodesmata
The symplastic pathway involves water moving through the living part of the plant cells.
8
Which cells in the phloem lack a nucleus but are alive?
Answer:
Sieve-tube elements
Sieve-tube elements are the main conducting cells of the phloem and depend on companion cells for their life functions.
9
Which of the following is an example of a 'short-day plant'?
Answer:
Poinsettia
Short-day plants flower when the night length exceeds a critical threshold, often in autumn or winter.
10
What is the main component of 'bark'?
Answer:
Secondary phloem and periderm
Bark refers to all tissues external to the vascular cambium in woody plants.