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Leaves - where photosynthesis occurs. Structure p. 252. A) cuticle. B) upper epidermis. C) palisade layer. D) spongy layer. E) lower epidermis. Cuticle - keeps moisture in. Upper epidermis - for protection. Palisade layer - where most of the chloroplasts are.
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Leaves - where photosynthesis occurs. Structure p. 252. A) cuticle B) upper epidermis C) palisade layer D) spongy layer E) lower epidermis
Cuticle - keeps moisture in. • Upper epidermis - for protection. • 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
- they close during hot weather to stop water loss. Guard cell - opens and closes the stomate. - they ‘swell up’ with water to close.
USES OF PLANTS(P. 259) • Clothing ex. cotton flax into linen
2) Medicines ex. 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.