Transcript 20.1 Origins of Plant Life

20.1 Origins of Plant Life
TODAY
• Review for plant summative
• Crossword Review
Legless Lizard
20.1 Origins of Plant Life
• Stomata are tiny holes in the cuticle of the leaf.
stoma
– can open and close
– allow air to move in and out
20.1 Origins of Plant Life
• Guard cells surround each stoma.
– Stomata open and close when guard cells change
shape.
guard cells
stoma
20.1 Origins of Plant Life
• A vascular system allows resources to move to different
parts of the plant.
– brings water and mineral nutrients up from roots
– disperses sugars from the leaves
– allows plants to grow higher off the ground
water
and
mineral
nutrients
sugars
20.1 Origins of Plant Life
• Pollen grains allow for reproduction without water.
– pollen grains contain a cell
that divides to form sperm
– can be carried by wind or
animals to female
structures
20.1 Origins of Plant Life
• A seed is a storage device for a plant embryo.
– Seeds are coated for
protection
– embryo develops
when environment is
favorable
20.1 Origins of Plant Life
Plants evolve with other organisms in their environment.
• Plants and other organisms can share a mutualistic
relationship.
– a mutualism is an interaction in which two species
benefit
– plant roots and certain fungi and bacteria
– flowering plants and their animal pollinators
20.1 Origins of Plant Life
• Plants have adaptations that prevent animals from eating
them.
– spines and thorns
– defensive chemicals
20.1 Origins of Plant Life
• Nonvascular plants grow
close to the ground to
absorb water and nutrients.
• Seedless plants rely on
free-standing water for
reproduction.
Example: Mosses
20.1 Origins of Plant Life
• Gymnosperms do not have seeds enclosed in fruit.
– most are cone-bearing
– pollen is produced
in male cones.
– eggs are
produced in
female cones.
– seeds develop on
scales of female
cones.
20.1 Origins of Plant Life
• Angiosperms have seeds enclosed in some type of fruit.
– Have flowers which are the reproductive structure
– A fruit is a mature ovary of a flower.
20.1 Origins of Plant Life
• Flowers allow for efficient pollination.
– animals feed on pollen or nectar
– pollen is spread from plant to plant in process
20.1 Origins of Plant Life
• There are three types of plant life spans.
– Annuals mature from seed, flower, and die in one year.
– Biennials take two years to compete life cycle.
– Perennials live more than two years.
Big bluestem
20.1 Origins of Plant Life
KEY CONCEPT
Plants have specialized cells and tissue systems.
20.1 Origins of Plant Life
Plant organs are made of three tissue systems.
• Dermal tissue covers the outside of a plant.
– protects the plant
– secretes cuticle of leaves
– forms outer bark of trees
20.1 Origins of Plant Life
• Ground tissue is found inside a plant.
– provides support
– stores materials in roots and stems
– most commonly made of parenchyma
20.1 Origins of Plant Life
• Vascular tissue transports water, minerals and organic
compounds.
– two networks of hollow
tubes
– xylem transports water
and minerals up
– phloem transports
photosynthetic products
stem
leaf
root
20.1 Origins of Plant Life
• Transpiration is the loss of
water vapor through leaves.
– water vapor exits leaf stomata
– helps pull water to the top
branches
20.1 Origins of Plant Life
• Roots
– support the plant
– absorb, transport,
and store nutrients
– root hairs help
absorption
20.1 Origins of Plant Life
• Stems
– support leaves and flowers
– house most of the vascular system
– store water
Baobab
Cactus
20.1 Origins of Plant Life
• Leaves
– collects sunlight for
photosynthesis
blade
petiole
20.1 Origins of Plant Life
Meristem (Meristematic tissue)
• Undifferentiated
cells/tissue
• Can turn into any type
of cell in the plant
20.1 Origins of Plant Life
Cambium
• Type of vascular
tissue that
produces new
xylem and phloem
• Responsible for
growth rings
20.1 Origins of Plant Life
• Leaves have many adaptations.
– for extreme temperatures,
ex: pine needles
– for water loss,
ex: cactus spines
– for aquatic environments,
ex: water lily
– for getting food,
ex: Venus’ flytrap
20.1 Origins of Plant Life
Today – Crossword Review
• Fix the following errors on the crossword
– In the first box for 2 down (put in the letters
MO) in the same box
– Cross out the first box for 8 down
– On the clues portion of the crossword, cross
out number 23 and write 29
– Cross out number 29 and write 23
Plant Summative Tomorrow
Poisonous plant project due Wednesday
20.1
of Plant Life
WordOrigins
Bank
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vascular
nonvascular
xylem
phloem
dermal
meristem
guardcells
ground
cambium
transpiration
stomata
oxygen
carbondioxide
Photosynthesis Monocot
chloroplast Dicot
pollen
sperm
seed
gymnosperm
angiosperm
flowers
roots
stem
leaves
Annual
Biennial
Perennial
20.1
Origins
of Plant
• (T08)
explain
theLife
basic
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classification of
plants
(T08) identify bryophytes,
pteridophytes, gymnosperms, and
angiosperms
(T08) explain how the following plant
organs and tissues are directly
(T08) explain the role of plant tissues
(meristematic, ground, dermal
and vascular tissues) with respect to plant
organs