Page 22 - 新思维科学学生用书7 样章

1.4 Cells, tissues and organs

Tissues

Living things, including animals and plants, are called organisms. There are many different kinds of
cell in an animal or a plant. Most of them are specialised to carry out a particular activity. Usually,
many cells of the same kind are grouped together.

A group of similar cells, which all work together to carry out a particular function, is called a tissue.
The diagrams show a tissue from a plant, and a tissue from an animal.

This is a diagram of a tissue from inside an onion. It is called an onion epidermis. This tissue covers

the surface of the layers inside the onion.

Onion epithelium

This is a diagram of ciliated epithelium – the tissue that lines the tubes leading down to our lungs. The
cilia all wave together, like grass in the wind.

cilia
nucleus

Ciliated epithelium

Questions

1 What is the function of the ciliated epithelium tissue? (Think about the function of a ciliated cell.)
2 The word ‘tissue’ has an everyday meaning and a different scientific meaning. Write two

sentences, one using the word ‘tissue’ with its everyday meaning, and one using the word ‘tissue’
with its scientific meaning.

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