Explanation

• The sequence of physiological changes by which a cell commits suicide is called apoptosis.
• This is a controlled, programmed cell death process that is crucial for maintaining healthy tissue function and development.

Explanation

• During prophase of mitosis in an animal cell, separation of centrioles occurs.
• The centrioles move to opposite poles of the cell to help organize the mitotic spindle.

Explanation

• The mismatched one is: Telophase → Nuclear membrane disappear.
• In Telophase, the nuclear membrane reforms around each set of chromosomes, not disappears.
• The nuclear envelope breaks down during Prophase, and reforms in Telophase.

Explanation

• In metaphase, the chromosomes (now consisting of two sister chromatids each) align themselves at the center of the cell, attached to the microtubules of the mitotic spindle.
• This forms the metaphase plate, where each chromosome is positioned at the equator of the cell, ready for separation.

Explanation

• Ribosomes are responsible for protein synthesis, not steroid synthesis.
• Steroid synthesis occurs in the endoplasmic reticulum and other organelles, but not in ribosomes.

Explanation

• Lysosome is the cell organelle found in animal cells that helps in intracellular digestion.
• It contains digestive enzymes and acids that break down cellular waste and foreign substances.

Explanation

The correct order is: Ribosomes → RER → Golgi body → Lysosome.

• Ribosomes: Protein synthesis occurs here, and the newly synthesized protein is released into the cytosol.
• RER (Rough Endoplasmic Reticulum): The protein is transported to the RER, where it is processed and modified (e.g., folding, glycosylation).
• Golgi body: The protein is packaged into vesicles and transported to the Golgi body, where it is further modified and sorted.
• Lysosome: The protein is delivered to lysosomes, where it can be used for various cellular processes (e.g., digestion, recycling).

Explanation

• The odd one out is Active transport.
• Active transport requires energy (ATP) to move substances against their concentration gradient.
• Whereas diffusion, facilitated diffusion and osmosis are passive processes.

Explanation

The secondary cell wall, found in plant cells, is primarily composed of:

• Cellulose (a polysaccharide, the main component of plant cell walls)
• Lignin (a complex organic compound that provides strength and rigidity)

Explanation

All three processes allow movement in and out of cells:

• Osmosis: Movement of water molecules from high concentration to low concentration through a selectively permeable membrane.
• Diffusion: Random movement of molecules from high concentration to low concentration until equilibrium is reached.
• Active transport: Movement of molecules from low concentration to high concentration using energy (ATP) to pump molecules across the cell membrane.