NCERT Solutions For Class 9 Science Chapter 6
Tissues

Parenchyma tissue is present in the following plant parts:

Stem, leaves, roots, flowers and vascular tissues.

Tissue is defined as a group of similar cells that are arranged and designed to perform a specific function

The specific function of cardiac muscle is to contract and relax rhythmically through the life and to facilitate the transportation of gases, nutrients and metabolites to various body parts through blood circulation.

Xylem tissue is a type of complex tissue. There are four types of elements that together make up the xylem tissue. The different types of elements are:

1. Trachieds: tubular structure
2. Vessels: tubular structures and along with trachieds they facilitate vertical conduction of water and minerals
3. Xylem parenchyma: stores food and facilitate sideways conduction of water.
4. Xylem fibres: supportive in function

Cork is a several layered thick outermost protective tissue present on mature plants. The cells of cork are compactly arranged without the intercellular spaces and are dead.  A special chemical called suberin is present in the cell walls of the cork cells that make them impermeable to gases and water. Due to this, it protects plants against water loss. It also protects plants against mechanical injury and temperature extremes. It also protects plants against fungal diseases by not allowing the parasitic fungi to grow on the plants. .

Labelled diagram of a neuron:

Stomata perform the following two functions;

1. They allow the exchange of gases (oxygen and carbon dioxide) between plants and atmosphere.
2. They facilitate the release of water vapours from the leaves and hence regulate the process of transpiration.

Epidermis performs the following functions in plants:

1. It covers the entire plant and protects all the parts of the plant.
2. It secrets a waxy, water resistant layer on outer surface of the aerial parts of the plants and prevents water loss.
3. It protects plants against mechanical injury and invasion of parasitic fungi.
4. It possesses stomata that facilitate gaseous exchange between plant and the atmosphere and allows transpiration to take place.
5. In roots, it aids in water absorption through the root hair present in root cells.        

(a) Squamous epithelial tissue

(b) Tendon

(c) Phloem

(d) Adipose tissue

(e) Blood

(f) Nervous tissue