Practice Questions

The thylakoid membranes inside chloroplasts house the photosystems, electron transport chains, and ATP synthase machinery needed for light harvesting.

The rigid plant cell wall serves as a physical barrier that prevents the invagination of the plasma membrane required for endocytosis.

Chromoplasts contain lipid-soluble carotenoids and develop from chloroplasts or leukoplasts, serving to attract pollinators and seed dispersers.

Microfilaments made of actin interact with myosin motor proteins to generate the mechanical constricting force required for the cleavage furrow.

Pectins are branched, hydrophilic polysaccharides that bind water and calcium ions, creating a flexible, hydrated gel matrix in primary walls.

Proteins and lipids are glycosylated in the rough ER lumen and sorted in the Golgi complex before being exported to form the animal glycocalyx.

The cross-linked network of cellulose microfibrils embedded in a matrix of pectin and hemicellulose provides massive tensile resistance against lysis.

Plant Golgi bodies exist as multiple disconnected stacks called dictyosomes distributed throughout the cytoplasm, rather than a single large complex.

Glyoxysomes are temporary, specialized plant peroxisomes that play an essential role in transforming stored seed lipids into transportable sugars.

Plasmolysis occurs when an external hypertonic solution draws water out of the central vacuole, causing the internal protoplast to collapse.