Bascis 3 - Tissues

• Biologie
• Middelbare school
• vwo
• Leerjaar 1

Basics 3 - Tissues

Tissues and cells

Cells

Building blocks of an organism

How many cells does the human body consist of?

30 biljoen  / 30.000 miljard

Tissues

Cells with the same shape and function

Bones: Bone tissue

Muscles: Muscle tissue

Extracellular material

Between the cells

- Fluid: in the brain

            - Hard substance: chalky               substance in the bones

Plants

Tissues

Epidermis (tissue)

- top and bottom of the leaf

- one cell layer thick

- protects the plant

Plants

Stomata

- - Laying in between epidermal cells

- Absorb CO2 and release O2

- Bottom of leaf

Tree

Cambium

- Tissue in the trunk of a tree

- Layer of cells close under the bark

Annual rings

• Trees only grow during spring and summer
• Spring > Big layer (lots of water while growing)
• Summer > Thin layer (little water while growing)
• Ring spring + ring summer = 1 annual ring

Homework

Please do exercises 1, 2, 3, 4, 6, 7, 8

From Unit 2, Basic 3: Tissues

Activity

Count the years on your tree stump