Question

Describe the role of the three non-reproductive organ systems found in plants (roots, stems, leaves). How do they differ in cell type and function?

Do animals have any cells comparable to meristems in plants? How are they similar/different?

Answer 1

Sol.

Role of the three non-reproductive organ systems found in plants are as follows:

(A) Role of root system in plants:

The main function of the root system are absorption of water and minerals from the soil, providing a proper anchorage to the plant parts, storing reserve food material and synthesis of plant growth regulators.

(B) Role of stems in plants:

The main function of the stem is spreading out branches bearing leaves, flowers and fruits. It conducts water, minerals and photosynthates. Some stems perform the function of storage of food, support, protection and of vegetative propagation.

(C) Role of leaves in plants:

Leaves play many important roles in plants. Photosynthesis takes place only in the green parts of the plants, mainly the leaves. Within the leaves, the mesophyll cells have a large number of Chloroplasts that are responsible for CO_{​​​​​2}​ fixation.

Leaves of some species of plants modifies themselves into other structures such as tendrils,spines for climbing and protection respectively.

They differ in cell type and function in the following manner:

Roots are having these types of cells and tissues namely pith in the center, phloem, metaxylem lies towards center and protoxylem lies towards the periphery called exarch type of arrangement of primary xylem, pericycle, endodermis, cortex, epidermis and root hairs.

Stems are having these types of cells and tissues namely pith in the center, protoxylem lies towards center (pith) and metaxylem lies towards the periphery of the stem called endarch type of arrangement of primary xylem, phloem, pericycle, endodermis, parenchymatous cells, hypodermis and epidermal hairs.

Leaves are having these types of cells and tissues namely stomatal apparatus, abaxial epidermis, mesophyll (spongy and palisade), xylem, phloem, bundle sheath and adaxial epidermis.

No, animals don't have cells comparable to meristems in plants. As we know plants show unlimited growth pattern while animals have limited growth. Due to this reason, animals have no meristem like cells as do plants have.