General Science — MCQ Practice Questions & Answers

Question 1

Photosynthesis occurs in?

Accepted Answer

Correct answer: C. Leaf — In chloroplasts of leaves.

Answer

A. Root

Answer

B. Stem

Answer

D. Flower

Question 2

Which of the following is the primary pigment responsible for absorbing light energy in the visible spectrum during photosynthesis?

Accepted Answer

Correct answer: A. Chlorophyll a — Chlorophyll a is the primary photosynthetic pigment that absorbs light in the blue and red regions of the electromagnetic spectrum.

Answer

B. Xanthophyll

Answer

C. Carotenoid

Answer

D. Anthocyanin

Question 3

The pH of cell sap in plant cells typically ranges between:

Accepted Answer

Correct answer: B. 4-6 — Plant cell sap is slightly acidic due to organic acids like malic acid and citric acid, maintaining pH between 4-6.

Answer

A. 2-3

Answer

C. 7-8

Answer

D. 8-9

Question 4

Which element is essential for the synthesis of chlorophyll molecule and forms the central atom in its structure?

Accepted Answer

Correct answer: B. Magnesium — Magnesium (Mg) is the central atom in the chlorophyll molecule, forming a coordinate bond with the porphyrin ring.

Answer

A. Iron

Answer

C. Zinc

Answer

D. Copper

Question 5

The phenomenon where plants bend towards light source is governed by which hormone?

Accepted Answer

Correct answer: B. Auxin — Auxin causes differential elongation of cells on the shaded side, resulting in phototropic response towards light.

Answer

A. Gibberellin

Answer

C. Cytokinin

Answer

D. Ethylene

Question 6

The process by which plants lose water as water vapour through stomata is called:

Accepted Answer

Correct answer: B. Transpiration — Transpiration is the loss of water vapour from aerial parts of plants, primarily through stomata during daytime.

Answer

A. Guttation

Answer

C. Imbibition

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D. Exudation

Question 7

A plant cell is placed in a hypertonic solution. Which physical phenomenon occurs, and what is the correct term for it?

Accepted Answer

Correct answer: A. Plasmolysis - protoplasm shrinks away from cell wall — In hypertonic solutions, water moves out of the cell due to osmosis, causing protoplasm to shrink away from the cell wall - this is plasmolysis. This is a fundamental osmotic principle tested in SSC/Railway exams.

Answer

B. Deplasmolysis - cell regains water

Answer

C. Turgor pressure increases

Answer

D. Cell wall becomes permeable

Question 8

Which of the following represents the correct order of plant tissues from outside to inside in a dicot stem?

Accepted Answer

Correct answer: A. Epidermis → Cortex → Phloem → Xylem → Pith — The correct radial arrangement in dicot stems is Epidermis (outermost) → Cortex → Vascular bundles (Phloem outer, Xylem inner) → Pith (center). This NCERT-based concept is frequently asked in SSC exams.

Answer

B. Epidermis → Cortex → Xylem → Phloem → Pith

Answer

C. Cuticle → Epidermis → Pith → Xylem → Phloem

Answer

D. Bark → Pith → Cortex → Xylem → Phloem

General Science - MCQ Practice Questions