chapter 9 “intro to plants” p. 240 plants -285,000 + species of plants. -all have tissues and...
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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 - to make their own food.
“Photosynthesis”
Plants first started in the oceansPlants 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 Plants are placed into nine phylumsphylums.
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 Ferns produce sporesspores for for reproduction.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 mosses3)Spike mosses
- 800+ species.- look like small evergreens.
ASSIGNMENT:
WORKSHEET “SIMPLE PLANTS”
3) SEED PLANTSSEED PLANTS (p. 252)
- 250,000+ known species.
- the seed is the reproductive organ.
There are two types of seed plants.1)Gymnosperms
ex. Pine, spruce. (p. 256)
- means “naked seed”- not protected by
a fruit.
- gymnosperms do not have flowers.
- produce seeds inside a cone.
-also called conifersconifers.
- are vascular plants.
2) Angiosperms
- are the flowering plants.
- means “closed container seed”.
- produce seeds inside a fruit *
- many have “showy” flowers like roses, lilacs, or tulips.
-some have flowers that are barely visible.
- like grasses.
There are TWO classes of angiosperms.
1) Monocots ex. corn,
tulips, grasses.
A) Have veins which run parallel.
B) Monocots have one cotyledon in their seed.
- a source of food for the developing plant.
- the seed cannot be split into two.
C) Monocots have flower parts in “threes”.
• Ex. Three petals
D) Monocots have scattered vascular bundles in their stems.
Dicots
A) have branched veins.
B) have flower parts in 4’s or 5’s.
C) Dicots have two cotyledons.
D) Have vascular bundles in rings.
Monocot or Dicot?
DICOTMONOCOT
MONOCOT DICOT
ASSIGNMENT:
QUESTIONS P. 251 (4 + 5)QUESTIONS P. 260 (2 + 3 + 5)
PARTS OF A COMPLEX PLANT- must have roots, stems, and leaves.Roots
- water and minerals used by the plant enter through the root.- anchors the plant.
- slows erosion.
Two types of Roots:
1) Tap root
Ex. carrot, radish, beet.
- thick - grows almost straight down.
- - used to store food
2) Fibrous root
Ex. Grasses, trees.
- forms a “web” of roots.
Both types have root hairs.
- are a single cell wide.
- absorbs water and nutrients.
Stems - support leaves and flowers.- have vascular
tissues that connect the roots to the leaves.1)Xylem
- transports water and nutrients from the roots to the leaves.
2) Phloem - transports food from the leaves to other parts of the plant.
Cambium
- growth tissue.
- makes the xylem and the phloem.
- makes the stem grow wider.
Two Types of Stems:
1) Herbaceous
- soft, flexible, green.
Ex. most flowers, grasses.
2) 2) WoodyWoody
- inflexible.
- “hard”.
- provides more support than herbaceous stems.
Ex. Trees.
ASSIGNMENT:
WORKSHEET “VASCULAR PLANTS”