Book A, From Bacteria to Plants

Section 1 -- What is life?

1. are made of cells. Some organisms are

one-celled (unicellular) such as bacteria

Other organisms are composed of many cells (multicellular)

	unicellular amoeba		multicellular scallop

Cells of multicellular organisms are specialized for certain jobs.
For example nerve cells carry messages to the brain while muscle cells move bones.
		nerve cell			muscle cell

2. use energy

3. grow (in size) and develop (change)

examples: baby develops into adult

seed develops into a tree

4. respond to surroundings

-a stimulus is a change in an

organism's environment that causes it to

react (or respond)

5. reproduce

		bacteria cells divide to reproduce

All organism need :

1. energy

2.water

3. living space

4. stable internal conditions ( homeostasis)

examples:

	-cactus conserving water		-snake basking in sun

Section 2 -- optional

Go to section 3