NET Biology MCQs

Cytoplasm includes the cytosol and suspended structures.
Many metabolic reactions occur there.

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.

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

Phagocytosis is often called cell eating.
Immune cells use it to engulf microbes and debris.

Pinocytosis is often called cell drinking.
Small vesicles form from the plasma membrane.