GAT Subject Biological Sciences MCQs

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.

Mitochondria convert energy from nutrients into ATP.
They contain their own DNA and ribosomes.

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

Chloroplasts contain chlorophyll and photosynthetic membranes.
They convert light energy into chemical energy.

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

The central vacuole stores water, ions, pigments, and wastes.
Its pressure helps support plant tissues.

Water enters the cell by osmosis.
Without a cell wall, excessive water entry can cause lysis.

The nucleus stores chromosomes in eukaryotic cells.
It also regulates gene expression and cell activities.