1. UNIT 16: PLANTS
Chapters 20-22
L.14.7

2. KEY CONCEPT Plant life began in the water and became adapted to land.

3. Land plants evolved from green algae.
Plants and green algae have many common traits.
both are photosynthetic eukaryotes
both have the same types of chlorophyll
both use starch as a storage product
both have cell walls with cellulose

4. Genetic analysis points to the common ancestor of all plants.
extinct green algae species
modern species are still common in lakes and ponds

5. Important plant characteristics likely originated in algae
multicellular body allowing for specialization of cells and tissues

6. True plants evolved through natural selection.
Ancestral algae lived in areas of shallow water.
Those that could survive longer dry periods were favored.
First true plants probably grew at edges of water.
True plants have embryos that develop while attached to female parent. (seeds!)

7. True plants evolved through natural selection.

8. Plants have adaptations that allow them to live on land.
Challenges of living on land have selected for certain plant adaptations.
A cuticle allows plants to retain moisture.
waxy, waterproof layer
holds moisture in

9. Stomata are tiny holes in the cuticle.
can open and close
allow air to move in and out

10. brings water and mineral nutrients up from roots
A vascular system allows resources to move to different parts of the plant.
specialized tissues
brings water and mineral nutrients up from roots
disperses sugars from the leaves
allows plants to grow higher off the ground
sugars
water and mineral nutrients

11. Lignin allows plants to grow upright.
plant cells
lignin
hardens cell walls of some vascular tissues
provides stiffness to stems

12. Pollen grains allow for reproduction without free-standing water.
pollen grains contain a cell that divides to form sperm
pollen can be carried by wind or animals to female structures

13. A seed is a storage device for a plant embryo.
seed coats protect embryos from drying wind and sunlight
embryo develops when environment is favorable
(moisture, temperature, etc just right)

14. 21.1: Plant Cells & Tissues
KEY CONCEPT Plants have specialized cells and tissue systems.

15. Plant organs are made of three tissue systems.
21.1: Plant Cells & Tissues
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

16. 21.1: Plant Cells & Tissues
Ground tissue is found inside a plant.
provides support
stores materials in roots and stems

17. Vascular tissue transports water, minerals and organic compounds.
21.1: Plant Cells & Tissues
stem
leaf
root
Vascular tissue transports water, minerals and organic compounds.
two networks of hollow tubes
xylem transports water and minerals UP from the roots to the rest of the plant
phloem transports photosynthetic products DOWN from the leaves to the stems & roots

18. 21.2: The Vascular System
KEY CONCEPT The vascular system allows for the transport of water, minerals, and sugars.

19. 21.2: The Vascular System
Transpiration is the loss of water vapor through leaves.
water vapor exits leaf stomata
helps pull water to the top branches

20. 21.3: Roots & Stems
KEY CONCEPT Roots and stems form the support system of vascular plants.

21. Roots anchor plants and absorb mineral nutrients from soil.
21.3: Roots & Stems
Roots anchor plants and absorb mineral nutrients from soil.
Roots provide many functions.
support the plant
absorb, transport, and store nutrients

22. Stems support plants, transport materials, and provide storage.
21.3: Roots & Stems
Stems support plants, transport materials, and provide storage.
Stems have many functions.
support leaves and flowers
house most of the vascular system
store water
Baobab trees
Cactus

23. Stems support plants, transport materials, and provide storage.
21.3: Roots & Stems
Stems support plants, transport materials, and provide storage.
Stems have many functions.
support leaves and flowers
house most of the vascular system
store water
grow underground for storage
Ginger rhizomes
Potato tubers

24. Stems support plants, transport materials, and provide storage.
21.3: Roots & Stems
Stems support plants, transport materials, and provide storage.
Stems have many functions.
support leaves and flowers
house most of the vascular system
store water
grow underground for storage
form new plants
Strawberry stolons

25. 21.3: Roots & Stems
Some stems are herbaceous and conduct photosynthesis.

26. Some stems can be woody, and form protective bark.

27. 21.4: Leaves
KEY CONCEPT Leaves absorb light and carry out photosynthesis.

28. Guard cells surround each stoma.
21.4: Leaves
Guard cells surround each stoma.
Stomata open and close when guard cells change shape.
When stomata are open, water evaporates and gas exchanges.
Stomata close at night and when plant loses too much water.
guard cells
stoma

29. Leaves may be simple, compound, or double compound.
READ BUT DON’T COPY
Leaves may be simple, compound, or double compound.
Simple leaf
Compound leaf
Double compound leaf

30. Leaf veins may be parallel or pinnate.
21.4: Leaves
READ BUT DON’T COPY
Leaf veins may be parallel or pinnate.
Pinnate veins
Parallel veins

31. Leaf margins may be toothed, entire, or lobed.
21.4: Leaves
READ BUT DON’T COPY
Leaf margins may be toothed, entire, or lobed.
Toothed margin
Entire margin
Lobed margin

32. 21.4: Leaves
READ BUT DON’T COPY
Leaves have many adaptations.
for extreme temperatures, ex: pine needles

33. 21.4: Leaves
READ BUT DON’T COPY
Leaves have many adaptations.
for extreme temperatures, ex: pine needles
for water loss, ex: cactus spines

34. 21.4: Leaves
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

35. 22.2: Reproduction in Plants
KEY CONCEPT Reproduction of flowering plants takes place within flowers.

36. Flowers contain reproductive organs protected by specialized leaves.
22.2: Reproduction in Plants
Flowers contain reproductive organs protected by specialized leaves.
Sepals and petals are modified leaves.
Sepals are outermost layer that protects developing flower
sepal

37. 22.2: Reproduction in Plants
A stamen is the male structure of the flower.
stamen
filament
anther
produces pollen grains

38. 22.2: Reproduction in Plants
The innermost layer of a flower is the female part (carpel).
carpel
style
stigma
ovary
ovary produces female gametophyte (“egg”)

39. Flowering plants can be pollinated by wind or animals.
22.2: Reproduction in Plants
Flowering plants can be pollinated by wind or animals.
Flowering plants pollinated when pollen grains land on stigma.
Wind pollinated flowers have small flowers and large amounts of pollen.

40. 22.2: Reproduction in Plants
Pollination occurs when a pollen grain lands on a stigma.
pollen tube
sperm
stigma
one cell from pollen grain forms pollen tube
other cell forms two sperm that travel down tube

41. Flowering plants go through the process of double fertilization.
endosperm
seed coat
embryo
one sperm fertilizes the egg
other sperm unites with polar nuclei, forming endosperm
endosperm provides food supply for embryo

42. 22.2: Reproduction in Plants
Each ovule becomes a seed.
The surrounding ovary grows into a fruit.