Leaves - where photosynthesis occurs. Structure p. 252.

A) cuticleB) upperepidermisC) palisade layer

D) spongy layer

E) lower epidermis

A) Cuticle - keeps moisture in.

B) Upper epidermis - for protection.

C) Palisade layer - where most of the chloroplasts are.- where the photosynthesis occurs.

D) Spongy layer - full of air spaces and more chloroplasts.

E) Lower epidermis

Stomate - opening for water vapor, CO2, and oxygen.

Guard cellGuard cell - opens and closes the stomate. - they ‘swell up’ with water to close.

- they close during hot weather to stop water loss.

Stomates and Stomates and Guard CellsGuard Cells.

USES OF PLANTS (P. 259)

1) Clothingex. cotton flax into linen

2) Medicinesex. aspirin (from tree bark)

3) Wood and paper- mostly from conifers.

4) Turpentine / resins/ dyes. (mostly from conifers).

5) Food (energy transfer)Sun --- plants --

animals

6) Creation of oxygen- thru photosynthesis.

Plant Evolution

- the seed plants ‘pushed out’ the ferns over 70 million years ago.

- seeds are more survivable than spores.

Gymnosperms are over 200 million years old.

Angiosperms are over 120 million years old.- are today’s most common form of plant life.

ASSIGNMENT:

WORKSHEET “PLANT STRUCTURE”