BIOL 1040 Unit 3

Plants and Fungi

Plant

Multicellular eukaryote the produces its own food by carrying out photosynthesis; cell wells contained primarily of cellulose, contrain true tissue; are sessile and inhabit terrestrial environments

Roots

Part of a plant below the ground that absorbs water and minerals from soil and transports through vascular tissue; anchors plant in place

Shoot

Consists of stem and leaves; above-ground plant containing flowers and fruits; mainly performs photosynthesis

Stationary Living Challenges

Obtaining food (plants now grow toward light), finding a mate (alternating haploid and diploid life stages and using organisms to transport male gametes), resisting predation (defend themselves through thorns or thicker leaves)

Non-Vascular

Lacking vessels to transport water and dissolved nutrients, instead of diffusion; bryophytes

Cuticle

Waxy layer on stem and leaves of land plants to prevent drying out

Living Challenges on Land (Colonizing Land)

Water conservation, gas/nutrient exchange with air and soil, support, reproduction

Bryophytes

Groups of plants that lack vascular tissue and move water and dissolved nutrients through the plant body by diffusion

Gametophyte

Haploid

Sporophyte

Diploid

Alternation of Generations

Life cycle of alternating haploid and diploid generations (haploid gametes at fertilization produce a new diploid cell that becomes a multicellular organism then starts over again)

Spores

Reproductive structure that have an alternation of generations; haploid and unicellular

Sporophyte

Diploid stage that generates haploid spores

Gametophyte

Haploid stage that generates gametes

Vascular Plants

Do not rely soley on osmosis and diffusion for water and nutrient transport; contain system of tubes that extends from roots to stems to leaves

Sporangia

Underside of leaves where haploid spores are released

Seed

An embryonic plant with its own supply of water and nutrients encased within a protective coating

Endosperm

Tissue of a mature seed that store fuel of the germination, growth, and development of the embryo and young seedling

Gymnosperms

Do not produce their seeds in a protective structure; usually found on the surface of scales of cone-like structure

Angiosperms

Seed-producing flowering anf fruit-bearing plants which seeds are enclosed in an ovule

Pollen Grains

A structure that contains the male gametophyte of a seed plant

Ovules

Structure within the ovary of flowering plants that gives rise to egg cells

Pollination

Fertilization of the egg cell in ovule by sperm cells in pollen grains

Flowers

Part of an angiosperm that contains the reproductive structures; consists of supporting stem with modified leaves

Stamen

Male reproductive structure of a flower consisting of anther and filament

Anther

Produces pollen

Filament

Supporting stalk

Carpel

Female reproductive structure of a flower including stigma, style, and ovary

Stigma

Sticky tip

Style

Elongated style

Ovary

Contains the ovules

Strategies for Attracting Pollinators

Bribery (offering nectar and the organism therefore carries pollen), trickery (flower decieves male bee into carrying pollen)

Double Fertilization

In angiosperms, the fertilization process in which two sperm are released by pollen grains, and one fuses with an egg to form a zygote while other fuses with two nuclei to form triploid endosperm

Seed Dispersal

Hitching a ride (projections/spines that attach to passing animals), flying and floating (structure allows them to be carried by wind or water), providing food source (fruit lures animals to eat seed and eliminate it)

Plant Predation Defense

Anatomical structures (have thick layers of bark, spines, spikes, and thorns that deter predators), sticky traps (engluf and smother attacking insects), chemicals (synthesize chemicals and induce physiological behavioral changes)

Fungi

Decomposers (break down the tissues of dead organisms by absorbing nutrients), sessile (anchored to organic material which they feed), chitin cell walls (same chemical producing the exoskeleton of insects

Hyphae Cells

Long strings of cells that make up mycelium

Mycelium

Mass of interconnecting hyphae that make up the structure of fungus

Penicillin

Fungus made molecule that can kill many kinds of bacteria

Mycorrhizae

Root fungi; symbiotic associations between roots and fungi which fungal structures are closely associated with rootlets and root hairs

Lichens

Symbiotic relationship between fungi and algae

Dermal Tissue

Covers and protects surface of the plant; often in single layer (epidermis); contain cuticle (reduce water loss)

Vascular Tissue

Transports water and nutrients throughout the plant (contains xylem and phloem)

Ground Tissue

Makes up bulk of plant and is where most of the plant’s metabloic activities are carried out (food storage, flexible structural, and rigid structural cells)

Leaves

Primary site of photosynthesis, conversion of energy from sun into food for plant

Stem

Provide structural support; position leaves to be exposed to sunlight; conduct food, water, and nutrients throughout plant

Roots

Absorb water and minerals from soil; anchor plant in place; storage of nutrients (starch)

Cotyledon

Part of plant embryo withinn seed that becomes first embryonic leaf

Monocots

One of major groups of flower plants; have one cotyledon; parallel veins, vascular tissue in scattered bundles; flowers in multiples of 3; fibrous roots

Eudicots/Dicots

One major group of flower plants; two cotyledons; branching veins, flower parts in multiples of four or five; taproot roots

Guard Cells

Form stomata for gas exchange

Cork Cells

Replace epidermal cells to provide thick layer of protection (bark)

Xylem

Conducts water and dissolved minerals absorbed by the roots to tissues through the plant

Phloem

Conducts sugar produced by photosynthesis in the leaves to tissues through the plant

Sieve Tubes

Tube structure formed from specialized cells in the phloem, that conducts sugar throughout the plant

Taproot System

Thicker primary roots with smaller roots branching from them; grown deep (dicots)

Fibrous Roots

Similarly sized roots branching out from stem; upper shallow parts and outward (monocots)

Pith

Monocots have a “ring” of vascular tissue with ground tissue on outside and inside

Root Hairs

Dermal cells that cover roots and morph into root hairs

Meristems

Where root stems grow as fast dividing undifferentiated cells

Apical Meristems

Promote vertical growth at tips of stems and roots

Lateral Meristems

Responsible for growth in width of stems and roots

Nodes

Places where leaves, flowers, or additional stems can grow

Leaves

Primary purpose is to undergo photosynthesis

Requirements for Plant Nutrition

Sunlight (provides energy to build molecules of sugar), water (essential for every chemical reaction), air (source of carbon dioxide to be used in sugar construction), soil (contains minerals essential for building new cells)

Essential Minerals for Plant Growth

Nitrogen, phosphorus, magnesium, potassium, sulfur, and calcium

Composition of Soil

Minerals (inorganic particles formed from breakdown of weathering rock, grouped in sand, silt, and clay), organic materials (carbon-containing matter formed from decomposition of dead organisms)

Nitrogen Fixation

The process of special bacteria in soil converting N₂ into NH₄⁺ or NO₃^- since plants need nitrogen

Crop Rotation

Legumes fix nitrogen in the soil, leaves require high amount of nitrogen, fruits need phosphorus and some nitrogen, roots need more potassium and phosphorus than nitrogen

Faciliated Diffusion

When the mineral concentrations are greater outside of the cell, the cell membrane allows the charged ions to pass through membranes

Active Transport

When the mineral concentrations are greater inside the cell, the cell membrane uses ATP allowing the charged ions to pass through the membranes

Water and Mineral Uptake

Possible because of evaporation, tension, and cohesion in a cohesion-tension mechanism

Evaporation

Due to low water concentration in the air relative to in the leaf, molecules are vaporized one by one

Tension

Water molecules form hydrogen bonds with one another causing them to stick together

Cohesion

Stickiness of water molecules links them together all the way down the roots, so as one molecule evaporates it pulls the molecule next to it and so on

Sugar Transport

Possible because of pressure-flow mechanism in which sugar is moved via active transport within the phloem cells