Define the term tissue"."

AcademicBiologyNCERTClass 9

A tissue is a group of cells having a similar structure organized to perform one or more specific functions, in a multicellular organism. There are four basic tissue types defined by their morphology and function: epithelial tissue, connective tissue, muscle tissue, and nervous tissue.


The term "tissue" was coined by a great histologer named Marie Francois Xavier Bi-Chat. Then, organs are formed by grouping together multiple tissues according to their function. 

There are "four" different types of tissues found in animals: 

1. Connective Tissue 

2. Muscle Tissue 

3. Nervous Tissue, and 

4. Epithelial Tissue.


In terms of botany, tissues are classified into three main types such as parenchyma, collenchyma, and sclerenchyma.

1. Parenchyma: Parenchyma tissues possess living cells, with thin cell walls. They are oval, elongated, and loosely packed with large intercellular spaces and dense cytoplasm.

They are located in the soft parts of the plant such as the cortex and pith.

2. Collenchyma: Collenchyma tissue possesses living cells with thick corners of the cell wall. They are oval-shaped, elongated, and tightly packed with no intercellular spaces.

They are located in the leaf stalks, below the epidermis in leaves and stem.

3. Sclerenchyma: Sclerenchymatous tissues possess dead cells with very thick cell walls due to lignin deposition. They are narrow and elongated.

These tissues are located in the leaf veins, surrounding the vascular bundle, and hard coverings of the seeds and nuts.

raja
Updated on 10-Oct-2022 12:47:28

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