Presentation on theme: "CHAPTER 9 “INTRO TO PLANTS” p. 240 Plants -285,000 + species of plants. -All have tissues and “organs”. Plants must have: cell walls -for support. chloroplasts."— Presentation transcript:
Plants -285,000 + species of plants. -All have tissues and “organs”. Plants must have: cell walls -for support. chloroplasts - to make their own food. “Photosynthesis”
Plants first started in the oceans Plants first started in the oceans. -the oldest fossil is 420 million years old. (p. 241) - it had no “real” leaves or roots. It had to adapt to living on land. 1) cell walls -provides support and structure. -stops cells from drying out.
2) cuticle - a waxy covering. - keeps water in. Plants are placed into nine phylums Plants are placed into nine phylums.
1) Nonvascular Plants - do not have any vessels or tubes to transport water or food. -called bryophytes - the most simple of plants. -are seedless.
Ex. mosses, liverworts. (p.247) - must live near moist areas. - no true roots. - but has root-like structures called rhizoids.
Vascular Plants - have vessels or “tubes” to transport water and food.
2) Seedless Vascular Plants -have tissues to transport water and food. -produce spores instead of seeds. Ex. ferns, horsetails. (p. 249 - 250)
Fern-like plants were dominant during the dinosaur era. - temperatures were much warmer back then. -some as large as trees. -most live in warm, moist areas today.
Many ferns formed into today’s layers of coal and oil. This process takes millions of years and lots of pressure.
Ferns have rhizomes (roots) and fronds (leaves).
Ferns produce spores for reproduction. -form under the fronds in cases called sori. -they look like brown bumps.
Other seedless plants: 1)Horsetails (p. 250) - ‘scouring rushes’ - very common 300 million years ago. - most types now extinct - only one genus left.
2)Club mosses 3)Spike mosses - 800 + species. - look like small evergreens.