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Warm-U
Describe five things you can remember
about fungi: (for example, what do they eat? what kind of cells do they have? where do you find fungi?
Etc.)
PlantsHolly Springs High School
Biology
What are plants?
• Multicellular
• Eukaryotes
• Cell walls made of cellulose
• Autotrophic
• Carry out photosynthesis
Plant Needs
• Sunlight
• Water and minerals
• Gas Exchange
• Movement/transport of water and nutrients
Overview of Plant Kingdom
Floweringplants
Cone-bearingplants
Ferns andtheir relatives
Mosses andtheir relatives
Green algaeancestor
Flowers; SeedsEnclosed in Fruit
Seeds
Water-Conducting(Vascular) Tissue
Gymnosperms
Angiosperms
^-thought to havearisen from multicellular green algae (a protist)
Mosses
Club mosses & Spike mosses
Ferns & Horsetails Gymnosperms Flowering
Plants
simple vascular tissue
vascular tissue becomes complex and branched
Seeds
1. Bryophytes – Mosses2. Ferns3. Angiosperms4. Gymnosperms
Moss
FOUR MAIN GROUPS OF PLANTS…
1. Bryophytes - Mosses
• No vascular tissues: water transported by osmosis
• Reproduction depends on water.
HornwortLiverwort
Moss
FOUR MAIN GROUPS OF PLANTS…
Mosses: non-vascular plants…
• …are plants without a water transfer system– to get water, they must be close to the
source
• Nonvascular plants like mosses and their relatives have no way to transport water up into the plant – this is why they must stay small and close to water.
How do nonvascular plants reproduce?
Mosses and their relatives have alternate generations, - one generation undergoes sexual reproduction, and the other undergoes asexual reproduction.
Life Cycle of a Mossbio.miami.edu
Sexual Reproduction
Asexual Reproduction
Spores but no seeds
2. Ferns
• First plants to have vascular tissues
• This allowed them to grow taller and get away from direct contact with water.
• Use spores to reproduce.
• Have roots, leaves, and stems.
Seed PlantsReproduction in either flowers or cones
3. Gymnosperms: (cones) naked seeds4. Angiosperms: (flowers) protected seeds
Both have vascular tissue
Sexual Reproduction: Pollination SEEDS – plant embryo is surrounded by a protective covering
3. GymnospermsSeeds produced on cones
Needles – good adaptation…why?
Cycad
Gymnosperm means :“naked seed”
Gymnosperms are the first of the seed plants.
4. AngiospermsSeeds produced in flowers and are protected
Special adaptations:
1) Flowers: a) attract animals which helps them transport seeds 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
4. Angiosperms* Cool Fact: Angiosperms consist of 235,000 species; 90% of the Plant Kingdom
Plant Features & Vocabulary
• Vascular tissue
• Xylem and phloem
• Roots
• Stems
• leaves
What is vascular tissue?Tissue that transports water and nutrients throughout the plant. Plant “veins” are a gathering of vascular tissue consisting of:
- XYLEM – carries water from roots upward to rest of the plant.
- PHLOEM – transports nutrients from the leaves to the rest of the plant
Can transport up, against gravity
www.deanza.edu
Vascular System
Plant Parts and Function1) Roots – underground organs that absorb water and minerals, keep plant upright
2) Stems – support & transport structures connecting roots and leaves
3) Leaves – organs where photosynthesis takes place, has pores for gas exchange
*All contain vascular tissue!
Root hairs increase surface area to absorb
more water.
Xylem moves water and nutrients up to the
plant.
Phloem moves carbohydrates down to
the roots sometimes storing them (example:
carrot)sparknotes.com
1) Rootsa) Taproots –help plant
reach water far below surface.
b) Fibrous roots – good at preventing erosion
2) StemsFunctions:
a) Produce leaves, branches and flowers
b) Hold leaves up to sunlight
c) Transports substances between roots and leaves
3) Leaves
Functions:
a) Photosynthesis
b) Transpiration: Plant loses water through leaves
c) Gas Exchange
Leaf Structures: Gas Exchange
• Stomata: pore-like openings in the underside of a leaf. Allows 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.
Stem
Root
Leaf
Ground tissue
Vascular tissue
Dermal tissue
Water and nutrient transport in plants1. Capillary Action – water moves up wall of
tube.
2. Transpiration – when water evaporates out/off, pulling force is created to take in water.
3. Root pressure – when soil moisture is high, water diffuses into roots
Plant Reproduction
Reproductive Anatomy• Flowering plants have male and female “parts”
• The Flower
•Sepals
•Petals
•Reproductive parts
Sepal – protects flower before it opens
protection
Petals – attract pollinators
Male and Female Parts• Male part: STAMEN
• filament (stalk)
• anther (tip)
•Female part: PISTIL
• stigma (sticky tip)
• style (stalk)
• ovary (base)
Flower Structure
Filament
AntherStigma
Style
Ovary
Carpel
PetalSepalOvule
Stamen
Pollination•Pollen (male gamete) from the anther is released and transported to stigma of other flowers:• By insects• By mammals• By birds• By wind
Ragweed pollen
•Ovule is fertilized
• grows to become seed protected by seed coat
• Fruits are mature ovaries
• protect and disperse seeds.
Fruits and Seeds
• Seeds = fertilized zygotes
(can become a new plant)
GerminationPlant emerging from seed (sprouting)Conditions need to be right…
What do you think these conditions are?- temperature?- water?- oxygen?
Patterns of Plant Growth• All plants follow a 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.
Hormone-producing cells
Target cells
Movement of
hormone
Auxins and Phototropism• Auxins: plant hormones that stimulate cell
elongation (higher amounts being produced in shaded areas cause plants to bend towards light).
• Auxins are also responsible for gravitotropism.
Tipremoved
Opaquecap
Clearcap
Opaque shiedover base
Highconcentration
of auxin
Lowconcentration
of auxin
Control
Cytokinins and Gibberellins
• Cytokinins: plant hormones produced in growing roots and in developing fruits & seeds.– Stimulate cell division and cause dormant seeds to
sprout.• Gibberellins: plant hormones that cause an
increase in the overall size of plants and their structures.
Ethylene
• Ethylene: In response to auxins, fruit tissues release small amounts of the hormone ethylene. – Ethylene then stimulates fruits to ripen.
Plant Responses (“Taxis” aka “tropisms”)
• Phototropism: causes a plant to grow toward a light source.
• Gravitotropism: causes the shoot of a germinating seed to grow out of the soil.
Plant Responses (cont.)• Thigmotropism: the response of plants to
touch • Click ME!