Name:________________________________________ Date:__________________ Pd:____
Note-taking Sheet
Part 1: Introduction to Plants & Plant Classification
Part 2: Plant Structure & Function
Main characteristics of Plants
1. Multicellular
4. Autotrophs
2. Eukaryotes
5. “Stationary animals that eat sunlight.”
3. Cell walls made of cellulose
Life Cycle
• Plants have a ______cycle that is characterized by alternation of generations.
• Two generations:
– Gametophyte – plant that produces haploid gametes (N).
• ____________________ – eggs and sperm that fuse to produce diploid individual.
– Sporophyte – plant that produces diploid spores (2N).
• Spores – reproductive cells that produce a new individual by _________________.
• All plants have gametophyte stage and sporophyte stage.
The lives of plants revolve around:
1. The need for sunlight, water and minerals.
– Plants use water quickly when the sun is shining.
2. Gas Exchange
– Plants require oxygen to support respiration as well as carbon dioxide for photosynthesis.
3. Movement of water and minerals.
– Plants take up water and minerals through their roots but make food in their leaves.
Early Plants-Early plants lived in the
.
• When they moved to land, they changed the environment in ways that made it possible for other organisms to
develop.
• Early plants probably looked like multicellular green algae.
Plants are divided into two categories:
• Bryophytes
–
-vascular plants.
– No tissue to transport water and nutrients throughout the plant.
• Tracheophytes
–
plants.
– Tissue to transport water and nutrients.
Bryophytes-Three divisions:
– Mosses
– Liverworts
– Hornworts
• The
plants – no tissue to transport water and nutrients. (No true roots, stems, or leaves.)
-The most common bryophytes.
• Live in
habitats – swamps, bogs, streams.
– Can tolerate very low temperatures. Most abundant plants in polar regions.
• Leaves of mosses are only one cell thick.
• Must be close to _________________ – found in moist shaded environments.
– Size is limited.
• Anchored to the ground by filaments called
.
• Obtain water and nutrients by absorbing them directly into plant _________________.
– Water seeps from one cell to the next.
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Plant Notes
Reproduction in bryophytes
• Reproduce with alternation of generations.
•
is dominant stage of life cycle.
• Sperm must swim to egg.
– Bryophytes must live in areas where
is available.
Tracheophytes
• Contain vascular tissue.
–
– carries water upward from roots to every part of the plant.
• Tracheids – hollow cells with thick walls that resist pressure.
–
– transports solutions of nutrients and carbohydrates produced by photosynthesis
downward from leaves to the roots.
• Produce lignin – a substance that makes cell walls rigid.
• Because of xylem, phloem and lignin, Tracheophytes can grow upright to reach great heights.
Tracheophytes are divided into two main groups
•
plants
– Club moss, horsetails and fern
•
plants
– Gymnosperms
– Angiosperms
Seedless plants – Have roots, stems and leaves.
– Roots – underground organs that absorb water and minerals.
– Leaves – photosynthetic organs that contains vascular tissue gathered into veins of xylem and phloem.
• The leaves of ferns are called
.
– Stems – supporting structures that connect roots and leaves, carrying water and nutrients.
Life Cycle of the Fern
• In ferns and other vascular plants, the diploid
is the dominant stage.
• Fern sporophytes produce haploid spores on the underside of their fronds in tiny containers called sporangia.
• Sporangia are grouped in clusters called
.
• The spores germinate and develop into haploid gametophytes.
• The prothallus, or small heart-shaped gametophyte plants that grow ___________________ of the sporophyte.
• On the underside of the gametophyte:
– Antheridia – where
are produced.
– Archegonia – where
are produced.
• Fertilization requires a thin film of water, allowing the sperm to swim to the eggs.
• The diploid zygote produced by fertilization grows into a new sporophyte plant.
• Sporophyte fronds may die in the winter, but rhizomes live through the winter and sprout again in the spring.
Seed Plants
• The ____________________________ group of photosynthetic organisms on land.
• Seed Plants are divided into two groups:
Gymnosperms
– bear seeds on the surface of
.
– Conifers such as pines and spruces.
– Ancient ginkgoes.
Angiosperms
•
plants that bear seeds within a layer of tissue that protects the seed.
• Include grass, flowering trees and shrubs, all flowers.
Reproduction in seed plants:
• Seed plants do
require water for fertilization of gametes.
Adaptations that allow this:
– Flowers or cones.
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Plant Notes
– The transfer of sperm by
.
– The protection of embryos in seeds.
Cones and Flowers
• Gametophytes of seed plants grow and develop in two types of sporophyte structures:
–
– seed bearing structures of gymnosperms.
–
– seed bearing structures of angiosperms.
Pollen
• In seed plants, the male gametophyte is contained in a pollen grain.
• The pollen grain is carried to the female gametophyte by wind, insects, birds, or small animals.
The female gametophyte is located in the ovary of the flower.
• This transfer is called
.
Seeds
• After fertilization, the zygote develops into a tiny plant called an
.
• A seed is an embryo of a plant that is encased in a protective covering and surrounded by a food supply.
– Embryo – the early developmental stage of the sporophyte plant.
– ________________ coat – surrounds and protects the embryo.
• The embryo can remain within the seed for years.
Gymnosperms
• Include gnetophytes, cycads, ginkgoes and conifers.
Ginkgoes
• Belong to phylum Ginkgophyta.
• Only one species: Ginkgo biloba.
• Common when
were alive.
• One of the oldest seed plant species alive today.
Conifers
• Belong to phylum Coniferophyta.
• Includes
, spruces, firs, cedars, sequoias, redwoods and yews.
• Some can live for more than 4,000 years.
• Most conifers are
.
• Some redwoods can grow more than 300 feet tall.
Angiosperms – Flowering Plants
• Angiosperms have unique reproductive organs known as
.
– The vast majority of living plant species.
– 235,000 species.
.Flowers attract animals such as bees or hummingbirds, which transport pollen from flower to flower.
– Much
than wind pollination used by gymnosperms
• Flowers contain ovaries, which surround and protect the seeds.
• After pollination, the ovary develops into a __________________________.
– A thick wall of tissue surrounding the seed.
– Fruit protects the seed and aids in its dispersal.
– Animals eat fruit and the seeds leave the digestive system ready to sprout.
• The animal disperses the seed when it travels.
• Plants use fruit to attract animals and increase the range of their habitat.
Diversity in Angiosperms
• Incredibly
with many different categories.
• Monocots and dicots.
• Woody and herbaceous plants.
• Annuals, biennials and perennials.
• These categories overlap!
Two groups of angiosperms
• Named for the number of
or cotyledons in the plant embryo.
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Plant Notes
Monocots and dicots.
Monocots
•
seed leaf or
.
• Leaves:
veins.
• Floral parts in multiples of
.
• Stems: Vascular bundles
throughout stem.
•
roots.
• Examples:
, wheat, lilies,
orchids and palms.
Dicots
•
cotyledons.
• Leaves:
veins.
• Floral parts in multiples of
or
.
• Stems: Vascular bundles arranged in a
.
•
• Examples: Roses, clover, tomatoes, oaks and daisies.
Monocots have fibrous roots, dicots have taproots
Woody and Herbaceous Plants
•
plants – made of cells with thick cell walls that support the cell body.
– Trees, shrubs and vines.
•
plants – do not produce wood as they grow.
– Dandelions and sunflowers.
Classification of Angiosperms based on life span:
– complete life cycle within one growing season.
• Petunias, pansies, cucumbers.
•
•
•
Complete life cycle within two growing seasons.
Parsley and celery.
Foxglove and Prince William.
•
Plants that live for more than two years.
– Grass, asparagus, maple trees.
Part II: Plant Structure and Function
The three principal organs in seed plants:
• Roots
• Stems
• Leaves
-Functions:
– ___________________ water and nutrients from the soil.
– __________________ plants to the ground.
– Hold plants upright.
Two types of roots:
1. Taproots:
– Found mainly in
.
– A primary root that is thick and grows deep into the soil.
– Carrot – a shorter taproot that stores sugar and starch.
2. Fibrous roots
– Found mainly in
.
– Thinner fibers
– Extensive branching.
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Plant Notes
Root hairs
• Small projections attached to roots that increase
for absorption.
• Root cap
• Thickened dead cells at the tip of the root that protects the growing tip as it pushes its way through the soil.
How do roots absorb water and minerals?
• Plants require minerals such as nitrogen, phosphorus, potassium and magnesium.
• Roots cells use active transport (_______) to pump mineral ions from the soil into the plant.
• This leaves the concentration of water higher outside the root.
• Water moves into the plant by ___________________.
Stems-Functions:
– Produce leaves, branches and flowers.
– Hold leaves up in the sunlight.
–
substances between roots and leaves (xylem and phloem).
Patterns of stem growth
• Primary growth
– Increase in
of stem.
– Takes place in all seed plants.
• Secondary growth
– Increase in
of stem.
– Mainly seen in dicots that grow extremely tall.
– The wood that makes up tree trunks is actually layers of xylem.
How does water move against gravity through the stem?
•
action
– Water molecules are attracted to each other and form hydrogen bonds between molecules (cohesion).
– Water molecules also form bonds with the cells of xylem tissue (adhesion).
• Capillary action is the tendency of water to rise in a thin tube.
• The thinner the tube, the _________________ the water will rise.
Leaves-The structure of a leaf is optimized for absorbing light and carrying out photosynthesis.
Blades-Thin flattened areas to collect sunlight.
Petiole-Thin
that attaches blade to stem.
Cuticle-Thick,
layer that covers outer layer of leaf cells and protects against water loss and injury.
Leaf functions
• Photosynthesis
–
– pore-like openings on the underside of the leaf that allow oxygen and carbon dioxide to
diffuse in and out of the leaf.
• Guard cells
– Each stoma consists of two guard cells that ______________ the opening and closing of the stoma by
responding to changes in water pressure.
Transpiration-_________% of the water taken up by the roots is _______________ during transpiration
• Water absorbed by the root hairs is drawn up the stem by capillary action like a siphon into the leaves where it is
released into the atmosphere.
• Replaced with water that is drawn ___________ roots by osmosis and transported by ________________.
• ______________________ is the major force that pulls water ______________________ through the stem.
Wilting
• The loss of
and pressure in the cells of the plant because of excessive transpiration.
• This pressure is known as turgor pressure.
Gas exchange
– Leaves take in carbon dioxide and give off
.
– Plants use oxygen and some of the food they make for growth and repair.
– In
, plants take in oxygen and give off carbon dioxide.
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Plant Notes
Reproduction in Seed Plants
• The sporophyte (2n plant) is the _________________________ stage in _____________ plants.
• The gametophyte stage (1n) is ____________________ deep within the tissues of the sporophyte plant.
– In gymnosperms, the gametophyte (
) is inside the cone.
– In angiosperms, the gametophyte is ________________ the ovary of the flower.
Structure of Flowers
• Flowers are reproductive organs that are composed of four types of specialized __________________:
– Sepals, petals, stamens, carpels
Sepals-The green, leaf-like structures that are seen under the flower petals in bloom.
• Surrounds and
the flower as it develops.
Petals-Color structures inside the sepals.
• Attract pollinators to the flower.
Stamen-Where male gametophyte is produced; composed of anther and filament.
– Filament –
– Anther – oval sac where meiosis takes place, producing male gametophyte in pollen grains.
Carpel (pistil) – innermost floral parts where female gametophyte is produced.
– Ovary – contains ovules which produce female gametophyte.
– Style – narrow extension of ovary.
– Stigma –
top of style where pollen grains frequently land.
Pollination
• In most gymnosperms, the ______________________carries the pollen grain to the female gametophyte.
• In most angiosperms, the pollen is transferred by ___________________.
– Insects, birds, bats.
– Bright colors and sweet nectar attract the animals.
– Pollination benefits the plant and the animal.
Pollen
lands on stigma of appropriate flower.
• Pollen grain contains ____________ sperm.
• Pollen grain begins to grow a pollen _____________.
• Pollen tube grows into a ____________________.
Two fertilizations takes place in the ovule.
– Sperm + egg 
zygote.
– The other sperm fuses with endosperm nucleus to form a structure that nourishes the seedling as it grows.
• As seed matures, the ovary walls thicken to form a fruit that encloses the developing seeds.
Fruit – ripened
that contains angiosperm seeds.
• Fruit may be fleshy (grapes, tomatoes) or tough (bean pods).
• Plants produce __________________.to ripen fruit.
Plant Responses
• Plants change their patterns and directions of growth in response to many different factors.
Tropisms – responses of plants to environmental __________________.
Phototropism-The tendency of a plant to grow toward a
source.
Gravitropism-The tendency of a plant to grow in a direction in response to the force of __________________..
• Both of these responses are under the control of the hormone
which stimulates cell elongation.
Thigmotropism-The response of plants to
 A plant that is touched regularly may be stunted in its growth.
• When the tip of a vine touches a surface, it wraps around it.
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Plant Notes