1. What is a Plant?

2. Basic Plant Characteristics
Eukaryotic
Multicellular
Autotrophs
Green Algae are the likely ancestors to today’s plants.

3. Shared Characteristics
Cell walls made of cellulose
Chlorophyll (green pigment)
Stores food as starch

4. Adaptations for Life on Land
Prevent water loss  cuticle
Carry out photosynthesis  leaves
Need to anchor into soil  roots
Transporting materials  vascular tissue

5. Two Plant Categories
Vascular plants have tube-like cells for transporting food and water
Nonvascular plants don’t have tube-like vessels for transport
Must use diffusion and osmosis to get food and water into cells

6. Plant Reproduction Early plants used spores
Later/newer plants used seeds
All plants go through the alternation of generations life cycle
life cycle where an organism alternates between a haploid gametophyte stage and a diploid sporophyte stage

8. Plant Diversity

9. Nonvascular Plants Division Bryophyta (mosses & liverworts)
Have no vascular tissue
Are small in size
Must live close to water

10. Seedless Vascular Plants
(club mosses, horsetails, ferns)
Contain vascular tissue for transport:
Xylem = dead cells that transport water up from roots
Phloem = living cells that transport sugar
Have roots and stems

12. Seedless plants  require water for reproduction
Seed plants  do NOT require water for reproduction

13. Seed Plants (cycads, ginkgos, conifers) “gymnosperms”
Have vascular tissue
Produce seeds in cones
Produce pollen that is carried by wind

14. Flowering Plants “angiosperms” – most of today’s plants species
Have flowers to help efficiently transfer gametes
Pollen is carried by pollinators
Seeds develop inside protective fruits that aid in dispersal

15. Monocotyledons “monocots”
Corn, grasses, grains, tulips, daffodils
Have one cotyledon
Have parallel leaf veins
Have fibrous root systems
Have floral parts in multiples of 3
Vascular bundles are scattered throughout stem

17. Dicotyledons “dicots”
Fruit trees, roses, daisies, azaleas
Have two cotyledons
Have branching leaf veins
Have a taproot system
Floral parts in multiples of 4 or 5
Vascular bundles are in a ring in stem

19. Plant Anatomy

21. Root System Functions Anchor plant in soil
Transport water and minerals
Store food (carrots, beets)

22. Shoot System
Stem Functions
Store products of photosynthesis

23. Shoot System
Translocation = the movement of sugars within the phloem

24. Shoot System
Transpiration = the movement of water within the xylem

25. Plant Growth
Meristem is any region of plant growth (root tips & shoot tips)

26. Plant Growth
Primary growth occurs when plants grow vertically (longer)
Secondary growth occrus when plants increase in girth (width)

28. Leaf Structure External Leaf Structure
The petiole connects the leaf to the stem
Leaves have a thin, flat shape

29. Leaf Structure Internal Leaf Structure
Cuticle – waxy, waterproof layer
Epidermis – outermost layer of cells
Stomata – openings in the leaf
Guard cells – surround stomata; let gases into and out of leaf

30. Leaf Structure
Palisade mesophyll – column-shaped cells where most photosynthesis occurs
Spongy mesophyll – cells surrounded by air spaces
Vein – tranports water into leaf

32. Plant Reproduction

33. Flower Structure Sepals enclose the bud Petals attract pollinators
Male ♂ part = stamen
Anther – produce pollen
Filament – holds up anther

34. Flower Structure Female ♀ part = pistil (carpel)
Stigma – pollen sticks to it
Style – connects stigma to ovary
Ovary – contains ovules with eggs
Flowers that are missing any parts are called imperfect

36. Pollination = the transfer of pollen from one flower to another
Adaptations for pollination
Bright petal colors (attract bees & butterflies)
Fragrant odors (attract flies & beetles)
Nectar (provides food)

39. Seed Formation Ovule wall becomes seed coat Zygote becomes embryo
Central cell/endosperm becomes food
Ovary develops
into fruit

41. Seed Dispersal Wind – (plumules, wings)
Water – (air pockets keep afloat)
Animals – (hooks latch onto fur, fruit gets eaten)

42. Seed Germination All seeds have a period of inactivity called dormancy
Germination (seed sprouting) occurs when dormancy is broken
Requires water, oxygen, and proper temperature
Some species require other conditions: frost, fire

44. Plant Tropisms phototropism – response to light
Tropisms are growth responses to external stimuli
phototropism – response to light
thigmotropism – response to touch
hydrotropism – response to water
gravitropism – response to gravity

46. Plant Tropisms
A negative tropism occurs when the plant grows AWAY from a stimulus
A positive tropism occurs when the plant grows TOWARDS a stimulus
the plant hormone involved with most tropisms is auxin