NEET Practice Questions (MCQs) with Answers & Solutions

In cyclic photophosphorylation, the same chlorophyll molecule acts as both the donor and acceptor of electrons. This process occurs in the thylakoid membrane of the chloroplast and is used to produce ATP without the production of NADPH or oxygen.

C₄ plants are adapted to efficiently perform photosynthesis even in low CO₂ concentrations. They have a specialized mechanism that concentrates CO₂ in the bundle sheath cells, minimizing photorespiration and allowing the plant to thrive in conditions where CO₂ is limited.

In C4 plants, the bundle sheath cells contain large chloroplasts that lack grana, hence they are agranal. This adaptation is crucial for the efficient functioning of the C4 pathway, where the Calvin cycle takes place in the bundle sheath cells.

All plastids have essentially the same structure because one type of plastid can be differentiated into another type of plastid depending on the cell's requirements. This flexibility allows plant cells to adapt to different metabolic needs and environmental conditions.

Lateral meristems, such as the cambium, are involved in the secondary growth of plants, which increases the thickness of stems and roots. The cambium is responsible for producing new layers of vascular tissue, including both xylem and phloem.

Hydathodes are specialized structures found in the epidermal tissue system of leaves. They are involved in the process of guttation, where water is exuded from the tips or edges of leaves. This is different from transpiration, which occurs through stomata.

Parenchyma is a living tissue in plants, consisting of cells with thin cell walls that are capable of cell division. It plays a key role in various physiological functions such as photosynthesis, storage, and tissue repair. In contrast, sclerenchyma, xylem vessels, and tracheids are typically composed of dead cells.

Collenchyma cells are a type of plant cell characterized by the uneven thickening of their cell walls, predominantly at the corners. This thickening is mainly composed of pectin along with cellulose, which provides flexibility and structural support to the plant parts.

Sclereids, also known as stone cells, are a type of sclerenchyma cell. They are typically found in various plant tissues, providing mechanical support and protection due to their thick, lignified cell walls. They are commonly found in fruits like pears and in the shells of nuts.