Question

What is a tissue?

Answer 1

Hint: Histology is the branch of science dealing with the study of different tissues. Tissue is a feature of multicellular organisms.

Complete Answer:
- The word tissue comes from a French verb which means to “weave”. A group of cells having similar shape and function act together to perform a specific function is known as a tissue. All the body parts are made up of tissues including the organs. Groups of tissues make organs. Different types of tissues are found in plants and animals.

Types of tissues in animals: There are four types of tissue present in animals.
1) Connective tissue- It connects other tissues or organs. These are fluid or semifluid in nature.
For example- blood is a fluid connective tissue.
2) Muscular tissue- It comprises a group of cells which can bring about contraction and relaxation.
For example skeletal muscles, cardiac muscles.
3) Nervous tissue –It is found in the brain, spinal cord which makes the nervous system.
Epithelial tissue- These tissues cover the surface of the organs. They protect the delicate organs. Example skin.

Types of tissues in plants: There are three types of tissue present in plants
1) Vascular tissue- Its function is to conduct water and minerals to plants. Xylem and phloem are the vascular tissue in plants.
2) Epidermal tissue -These are the single layer of cells covering the plant’s root, shoot stem, flowers, leaves. It guards plants against water loss, physical damage.
3) Ground tissue- These are the tissues which provide structural support to the plant. They are of three types- parenchyma, sclerenchyma and collenchyma.

Note: A tissue is a cellular organisational level between cells and a complete organ. It is composed of structurally and functionally similar cells. Tissues are absent in unicellular organisms.