Question

Hard lignified thick walled long and painted cells constitute.
A. Parenchyma.
B. Collenchyma.
C. Sclereids.
D. Sclerenchyma

Answer 1

Plant cells are eukaryotic cells; which means they have a membrane bound nucleus and organelles. Plant cells have cell walls outside the cell membrane. The different types of plant cells include- Collenchyma, Parenchyma, Sclerenchyma, Xylem and Phloem. They have different cellular structures that are responsible for better functioning and survival.

Complete answer:
Option A: Parenchyma cells have thin primary cell walls and cytoplasm. These cells are the biochemical machines of the plant i.e.; these cells are capable of performing many biochemical reactions in plants For example:- In epidermis, these are specialized for light penetration and regulation of gas exchange.

Option B: Collenchyma- Collenchyma cells are quite elongated and have irregularly thickened cell walls. Their function is to provide support and wind resistance to the plant. Example includes- Strings running through a stalk of celery.

Option C: Sclereids- Sclereids are a type of sclerenchyma cell. They are small bundles of Sclerenchyma tissue in plants. They are thick elongated cells having branched pits.

Option D: Sclerenchyma- Sclerenchyma cells are hard, thick cells and have extremely thick cell walls. They do not participate in the developing activities of the plant, their main function is to provide support and structure to the plant. Their cell wall is composed of lignin.

Hence, the correct answer is option (D).

Note: The ground tissue meristem gives rise to the ground tissue system which has tissues like Parenchyma, Collenchyma and Sclerenchyma. The sclerenchyma is mainly found in the cortex of stems and leaves. When it is matured, it has dead cells that have thick walls that are heavy and contain lignin and high content of cellulose. Types of sclerenchyma include the sclereids and fibres.