1. Holly Springs High School
Plants
Holly Springs High School
Biology

2. What is brown and really really sticky?

3. Plant defense
Tomato plant releases chemicals that attract wasps: Click HERE
Hornworm on tomato plant with wasp larvae. (Shooting Creek, NC 07/16)

4. Plants -Multicellular -Autotrophic -Eukaryotes
-Cell Walls made of cellulose
-Carry out photosynthesis using the green pigments chlorophyll a and b

5. Plant Life Cycle Plant Needs Two alternating phases
- Sporophyte – diploid (2n) stage
- Gametophyte – haploid (n) stage
Plant Needs
-Sunlight
-Water and minerals
-Gas Exchange
-Movement/transport of water and nutrients

6. Overview of Plant Kingdom
Gymnosperms
Cone-bearing plants
Ferns and their relatives
Angiosperms
Flowering plants
Mosses and their relatives
Flowers; Seeds Enclosed in Fruit
Seeds
Water-Conducting (Vascular) Tissue
Green algae ancestor
^- thought to have arisen from multicellular green algae (a protist)

7. 1. Bryophytes - Mosses Moss No vascular tissues
FOUR MAIN GROUPS OF PLANTS…
Moss
1. Bryophytes - Mosses
No vascular tissues
water transported by osmosis
reproduction depends on water.
Liverwort
Hornwort

8. 2. Ferns Have vascular tissues to transport water.
Use spores to reproduce.
Have roots, leaves, and stems.

9. Seed Plants Reproduction in flowers or cones
3. Gymnosperms (cones) naked seeds
4. Angiosperms (flowers) protected seeds
Pollination:
SEEDS – plant embryo surrounded by a protective covering
Vascular tissue
Pollen is male gametophyte (sperm)

10. Gymnosperms Needles – good adaptation…why? Seeds produced on cones
Sequoia
Cycad

11. Angiosperms Categorized by the number of seed leaves (cotyledons)
Monocot: one cotyledon, Dicot: two cotyledons
Monocots
Dicots
Single cotyledon
Parallel veins
Floral parts often in multiples of 3
Vascular bundles scattered throughout stem
Fibrous roots
Two cotyledons
Branched veins
Floral parts often in multiples of 4 or 5
Vascular bundles arranged in a ring
Taproot
Seeds
Leaves
Flowers
Stems
Roots

12. Angiosperms
*Cool Fact: Angiosperms consist of 235,000 species; 90% of the Plant Kingdom
Special adaptations:
1) Flowers: a) attract animals which helps them transport seeds and b) contain ovaries which surround and protect seeds
2) Fruit: Protects seeds and is a bribe to animals to eat and spread the seeds elsewhere

13. Vascular tissue
Function is to transport water and nutrients throughout the plant. “Veins” are a gathering of vascular tissue consisting of:
- XYLEM – carries water from roots
upward to rest of the plant.
- PHLOEM – transports nutrients to
the rest of the plant
Can transport against gravity

14. Vascular System

15. Plant Parts and Function
1) Roots – underground organs that absorb water and minerals, keep plant upright
2) Stems – support & transport structure connecting roots and leaves
3) Leaves – organ where photosynthesis takes place, has adjustable pores for gas exchange
*All contain vascular tissue!

16. Roots
Taproots – mainly in dicots, help plant reach waters far below surface.
Fibrous roots – mainly in monocots – good at preventing erosion

17. 2) Stems Functions: a) Produce leaves, branches and flowers
b) Hold leaves up to sunlight
c) Transport substances between roots and leaves
buds

18. 3) Leaves Functions: Photosynthesis
Transpiration: Plant loses water through leaves
Gas Exchange: Take in CO2 and release O2 during photosynthesis. Guard cells open and close in response to water pressure.

19. Leaf Structures
Mesophyll: make up the bulk of most leaves, packed with chloroplasts and carry out nearly all the photosynthetic activity.
Palisade mesophyll: just under the epidermis. They absorb much of the light that enters the leaf.
Spongy mesophyll: beneath the palisade layer, with many air spaces.
Xylem: transport water.
Phloem: transport nutrients and products of photosynthesis.

20. Leaf Structures
Stomata: pore-like openings in the underside of a leaf. Allow CO2 and O2 to diffuse in and out.
Guard Cells: specialized cells in the epidermis that control the opening and closing of stomata. Each stoma has two guard cells.

21. Leaf Structure Cuticle Veins Epidermis Palisade mesophyll Xylem Phloem
Spongy mesophyll
Epidermis
Stoma
Guard cells

22. Water and nutrient transport in plants
Capillary Action – water moves up wall of tube.
Transpiration – when water evaporates out/off, pulling force is created to take in water.
Root pressure – when soil moisture is high, water diffuses into roots

23. Flower Structure Stamen Carpel Stigma Anther Style Filament Ovary
Petal
Ovule
Sepal

25. Seeds = fertilized zygotes (would become a new plant)

26. What did the male stamen say to the female pistol?
I like your style!

27. Pollination
Pollen (the male gamete) from the anther is released and transported to stigma of other flowers:
By insects
By mammals
By birds
By wind
Ragweed pollen

28. Fruits and Seeds
Ovule is fertilized, and grows to become seed, protected by seed coat
Fruits are mature ovaries, to protect and disperse seeds.

29. Germination Plant emerging from seed (sprouting)
Conditions need to be right… What do you think these conditions are?
-temperature
-water
-oxygen (for aerobic respiration to occur…plant needs to obtain energy)

30. Patterns of Plant Growth
Hormone-producing cells
All plants follow a highly regulated pattern of growth that continues throughout the plant’s life.
Plant hormones: chemical substances that control a plant’s patterns of growth and development, and the plant’s responses to environmental stimuli.
Movement of hormone
Target cells

31. Auxins and Phototropism
Auxins: plant hormones produced in the apical meristem. They stimulate cell elongation (with higher amounts being produced in shaded areas).
Auxins are also responsible for gravitropism.
High concentration of auxin
Low concentration of auxin
Tip removed
Opaque cap
Clear cap
Opaque shied over base
Control

32. Cytokinins and Gibberellins
Cytokinins: plant hormones that are produced in growing roots and in developing fruits and seeds.
They stimulate cell division and the growth of lateral buds in plants, and cause dormant seeds to sprout.
Gibberellins: plant hormones that cause an increase in the overall size of plants and individual plant structures.

33. Ethylene
Ethylene: In response to auxins, fruit tissues release small amounts of the hormone ethylene. Ethylene then stimulates fruits to ripen.

34. Plant Responses (“Taxis” aka “tropisms”
Phototropism: causes a plant to grow toward a light source.
Gravitropism: causes the shoot of a germinating seed to grow out of the soil.

35. Plant Responses (cont.)
Thigmotropism: the response of plants to touch. NASTIC RESPONSE
Click ME!

36. Show lilly grown ppt