GAT Subject Biological Sciences MCQs

Plasmolysis occurs in a hypertonic environment.
The vacuole shrinks and the membrane pulls inward.

Prokaryotes lack a membrane-bound nucleus.
Their DNA is located in a nucleoid region.

The cytoskeleton includes microtubules, microfilaments, and intermediate filaments.
It supports transport, division, and movement.

Microtubules form tracks for motor proteins.
They also form the mitotic spindle, cilia, and flagella.

Microfilaments are mainly composed of actin.
They participate in cell crawling, cytokinesis, and muscle contraction.

Diffusion results from random molecular motion.
It continues until concentration differences are reduced.

Water moves toward the side with higher effective solute concentration.
Osmosis affects cell volume and turgor.

Channels and carriers help polar or charged substances cross membranes.
No direct energy input is required.

Active transport uses pumps or coupled carriers.
It maintains ion gradients and cell homeostasis.

The plasma membrane surrounds material and pinches inward.
Phagocytosis and pinocytosis are forms of endocytosis.

Lysosomes break down macromolecules and damaged cell parts.
Their enzymes work best in an acidic environment.

Exocytosis secretes hormones, enzymes, and neurotransmitters.
It also adds membrane components to the cell surface.