5
Title:
.
Cells are the basic building units of life, and there are about 100 trillion cells in the human body!
But did you know that some living things are made of just one cell? They are called single-celled
living things and some examples of these are bacteria and yeast.
Because cells are so tiny, we need powerful microscopes to observe them. Thanks to these
microscopes, scientists have been able to study cells and make discoveries. For example, about
200 years ago, a scientist called Louis Pasteur discovered a way to kill germs. His discovery is
known as pasteurisation, and it has helped save millions of lives!
a)
Human bodies have many cells but there are
.
b)
Microscopes have helped
.
c)
Louis Pasteur’s discovery was important because:
.
All animal and plant cells have three basic parts: the
, the
and
the organelles. In plant cells there is also a
outside the membrane.
4
Fill in the titles and draw lines to the parts. Then complete the sentences.
5
Write a title, then complete the sentences below using your own words.
A
cell
Cytoplasm
Nucleus
Cell wall/membrane
An
cell
