kingdom plantae · •non-vascular plants:-mosses, liverworts, and hornworts ... •nonvascular...
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Kingdom Plantae
Botany - the study of plants.
SummaryAll Plants are autotrophs that produce food byphotosynthesis.
• Plants are loosely organized into 4 groupsbased on the presence or absence of vasculartissue and seeds.
Main Characteristics Include:1. Cell walls composed of cellulose2. Non-motile3. Eukaryotic4. Multicellular
VASCULAR SYSTEM- A transportation system within a plant for water and sugar distribution.
SEED- An encapsulated plant embryo; a fertilized ovule of a plant.
SPORE- one-celled, reproductive unit capable of giving rise to a new individual without sexual fusion
Vascular tissue
• Vascular tissue - tissue that transports waterand sugars throughout an entire plant.
• Plants lacking vascular tissue are calledbryophytes.
• Plants which have vascular tissue are calledtracheophytes.
• Vascular tissue is made up of xylem and phloemcells.
- Xylem carries water and minerals to the leaves.
- Phloem transports food synthesized in leavesthroughout the plant.
• Land plants have acuticle and stomata(singular stoma).
- Cuticle is a noncellularlayer secreted by
epidermal cells toprotect cells from dryingout.
- Stomata are pores in theepidermis of a plant, to
permit the exchange ofgases between the plantand the air around it.
Bryophytes• Non-vascular plants:
- Mosses, liverworts, and hornworts
BRYOPHYTES(Phylum Bryophyta)
• Nonvascular land plants use diffusion and osmosis totransport materials throughout the plant.
• small in size they grow close to the ground in moist,shaded areas.
• lack true roots, stems and leaves, they are anchored tothe ground by structures called rhizoids.
• Bryophytes are the only plants to have a life cycle that ispredominantly in the haploid gametophyte stage. They
produce male and female gametes that require water toallow the sperm to swim to an egg creating a zygote thatwill develop into a new sporophyte.
Tracheophytes
• Vascular plants:- Ferns, gymnosperms, and angiosperms
- Sporophyte dominated life cycle
- Seedless (spore bearing) Seeded Plants
TRACHEOPHYTES(Phylum Tracheophyta)
• Tracheophytes have vascular tissues (xylem &phloem). That allow plants to grow muchtaller, by being able to draw water up through
their bodies.
• Means of reproduction:
- spores: for club mosses, horsetails, and ferns.
- seeds: for flowering plants (angiosperms) andconifers (gymnosperms).
Seedless Vascular Plants (Ferns)• Reproduce by spores, and have an alternation ofgenerations that is dominated by the sporophyte
life cycle. (opposite non-vascular)
• Ferns are the most diverse seedless vascularplant. (dinner to decorations)
• Life Cycle see page 173
- Write a list of ALL key words that come out of the lifecycle of the fern. Underline any terminology you haveencountered before and note where you have used
the word before.
Life Cycles of Plants
• An alternating cycle of both a haploid gametestage (Gametophyte) and a diploid sporestage (Sporophyte). This cycle is known as theAlternation of Generations
- Sporophytes produce haploid spores throughmeiosis (division of the chromosome) that cangrow without any fertilization.
- The spore grows into a gametophyte that producemale and female gametes that can fuse anddevelop into another sporophyte
Alternation of Generations
Seed Producing Tracheophytes
• There are two main groupings for seedproducing plants:
- Gymnosperms (conifers and relatives)- conebearing plants that have seeds exposed on theircones scales.
- Angiosperms (flowering plants) - plants withprotected reproductive structures that have
adaptations to increase the likelihood ofreproduction.
What is a Seed?
• A seed is a multi-cellular structure containingan embryo and a food source.
• The embryo consists of a:- An immature root
- An immature shoot
- One or two seed leaves
• Seeds have hard protective structures and cansurvive without water for years. They can alsobe carried great distances by animals etc…
Gymnosperms
• Have all normal plantcharacteristics
• Have seeds on theircone scales
• Most are coniferoustrees (pines, spruce,etc…)
Survival Strategies• Reproduction with male pollen and pollen tubesremoves the need for moisture.
• Protective bark prevents water loss
• Shape helps prevent snow/ice damage, andincreases the area for photosynthesis to occur.
• Needle-like leaves have thick cuticle and sunkenstomata to prevent water loss.
• Do not loose their needles so photosynthesis canbegin earlier and they do not need extra nutrients
to grow new leaves.
Angiosperms (flowering plants)
• Plants that protect their seeds within the bodyof a fruit.
• Make up ¾’s of all plants, including:
- Trees, shrubs, herbs, grasses, water plants, etc…
• Divided into two large classes based on thenumber of seed leaves (cotyledons)
- Monocots - one seed leaf (grasses, lilies)
- Dicots - two seed leaves (roses, peas, mapletrees)
Diversity and success of theAngiosperms :
• The angiosperms are the most diverse plantgroup.
• They can self-pollinate (clone) or cross-pollinate with another plant.
• Also, this diversity is due to a variety of otherfactors, such as:
1) Presence of specialized structures
• Plants attract animal pollinators with colour anda supply of food (often nectar) to carry pollen
from plant to plant- Different flower colors, smells, and shapes attractdifferent pollinators.
- Eg. Bees can’t see red, so they are often on blueor yellow flowers.
- Flies are attracted to flowers such as stink-cabbage.
- Many insects see UV spectrum. (See Fig. 6.14, pg.177)
2) Seeds are protected
- Flowers are sporophytes that do not producespores.
- The pollen grains, and the eggs are all that remainof the gametophyte generation.
- The embryo is enclosed in hard tissue to form aseed. The seed case enables the embryonic plantto survive adverse weather conditions such as
drought, hot or arid periods and cold.
3) Function of the fruit in seeddispersal
• Some seeds in fruits are easily dispersed bywind and by water. Eg. Coconut
• Some fruits are eaten and dispersed byanimals. The seed resist digestion and willpass intact in an animal’s feces to germinate ina new spot.
4) The presence of specialized tissues
• Some plants possess special tissues andbehaviours to help them survive heat, cold,and droughts.
- Eg. small leaf hairs and sunken stomata help toreduce water loss.
Now make like a tree and leave!!
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