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 the 'cortex' of a root primarily composed of?
Answer:
Parenchyma cells
The cortex is the ground tissue between the epidermis and the vascular cylinder. It stores carbohydrates and helps transport water and minerals to the center of the root.
42
Which of the following is a characteristic of a 'long-day' plant?
Answer:
It flowers when the night is shorter than a critical duration
Long-day plants (short-night plants) flower typically in late spring or early summer when the dark period is less than a certain number of hours.
43
What is 'phloem loading'?
Answer:
The active transport of sugars into sieve-tube elements
Phloem loading often requires metabolic energy to move sucrose against its concentration gradient from the source cells into the sieve-tube elements.
44
Which plant tissue covers and protects the plant body?
Answer:
Dermal tissue
Dermal tissue forms the outer covering of the plant. In non-woody plants, it is usually a single layer called the epidermis.
45
The 'sapwood' of a tree is:
Answer:
The active, conducting secondary xylem
Sapwood is the younger, outer layer of wood that still transports water and minerals. Heartwood is the older, inner wood that has stopped conducting.
46
Which of the following is a function of 'Auxin'?
Answer:
Cell elongation in shoots
Auxin stimulates the elongation of cells in young shoots. According to the acid growth hypothesis, auxin triggers the loosening of cell walls, allowing the cell to expand due to turgor pressure.
47
What is the 'zone of maturation' in a root?
Answer:
Where cells differentiate into specialized types
Also called the zone of differentiation, this is where cells complete their development and become distinct tissues like epidermis, cortex, or vascular tissue.
48
Which cells in the leaf control the size of the stomatal pore?
Answer:
Guard cells
Guard cells are pairs of specialized epidermal cells. By adjusting their turgidity through ion transport, they open or close the stoma to balance CO2 intake and water loss.
49
Which structure protects the root apical meristem?
Answer:
Root cap
The root cap covers the tip of the root. It protects the meristem from abrasion by soil particles and senses gravity to guide root growth.
50
What is the function of 'pith' in a dicot stem?
Answer:
Internal storage of nutrients
Pith is the ground tissue internal to the vascular tissue in many stems. It is primarily composed of parenchyma cells that function in the storage of starch and other nutrients.