Unit III Biology Study Set - Fungal Diversity: Plant Form and Function

Decomposers

Sustaining ones self by secreting hydrolytic enzymes into a given environment, decaying matter, and absorbing the nutrients through networks of filaments

Hyphae

Tiny filaments that absorb decomposed nutrients, and allow cytoplasm to flow through

Chitin

A strong polysaccharide that composes the cell wall - helps aid in absorption and avoids rupturing when in a hypotonic environment

Mycelium

Composed of hyphae that extend up into the fruiting body (fruiting body produces spores)

Coenocytic

Unsegmented hyphae

Septate

Segmented hyphae

Why do Hyphae Lack Well Defined Cells?

Because hyphae need maximum surface area to effectively absorb nutrients

Arbuscules

Structures formed by hyphae that enter into living cells and acquire nutrients

Mycorrhizal Fungi

Fungi that exchange nutrients with the roots of plants, and effectively increase the absorption area of plants (mutualistic relationship)

Asexual Reproduction

Haploid spores produced via mitosis

Fungal Sexual Reproduction

Mating types release pheromones from their mycelia, if a fungi of a different type is nearby, they will grow towards each other and fuse when they meet. Then the haploid nuclei fuse and create a diploid zygote for a short period of time prior to undergoing meiosis and forming haploid spores

Plasmogamy

Fusion of the cytoplasm between two different types of fungi

Heterokaryotic Mycelium

Post plasmogamy when the haploid nuclei from each type of fungi exist in one singular organism

Karyogamy

When the haploid nuclei fuse together and form a diploid zygote

Alteration of Generations

The life cycle of all plants that consist of a gametophyte and a sporophyte stage

Gametophyte

A haploid multicellular organism that produces gametes (the gametes later fuse with each other to form diploid saprophytes)

Sporophyte

A diploid multicellular organism that produce reproductive cells that are capable of developing into additional haploid organisms called spores (these spores continue on and develop into a multicellular gametophyte)

Multicellular Dependent Embryos

During the embryonic development of a sporophyte when it is surrounded, protected and given nutrients by maternal tissue of the gametophyte

Wall Spores

Produced in sporangia - a protein called sporopollenium fills the walls to protect spores from the environment

Spores

Haploid organisms produced in the sporangia of sporophytes

Multicellular Gametangia

Where eggs and sperm are produced as part of the gametophyte stage

Antheridia

Sperm producing gametangia

Archegonia

Female egg producing gametangia

Apical Meristems

A highly mitotic region tip on plants in which they grow from - can develop into a leaf or shoot out a root due to their high stem cell abundance

Cuticle

The waxy outer layer on plants to prevent excessive water loss

Stomata

Opening on photosynthetic organisms that allow for gas exchange - opening and closing regulated by guard cells

Xylem

Transports mainly water and minerals from the root anchoring structures - strengthened by the polymer lignin

Seeds

An embryo packed with nutrients that can be cast away from the parent and survive extended periods of time and germinate (not an apparent feature until angiosperms and gymnosperms develop)

Homosporus

A plant that produces only one type of spore (bisexual gametophyte that will develop into either a male or female gametophyte)

Heterosporus

A plant that can produce multiple kinds of spores (either microsporangium - male gametophyte production or megasporangium - female gametophyte production)

Non-vascular Plant Characteristics

1. No true roots, seeds, leaves, or vascular tissue

2. Gametophyte dominant

3. Thin structures to enable water diffusion

4. Anchored into the ground via rhizoids (no absorption apparatus)

5. Flagellated sperm

Phyla Hepatophyta: Liverworts

Nonvascular herbs that use gemma cups to go through asexual reproduction

Gemma Cups

Cups containing small fragments of liverwort tissue that are splashed out by water and grow in surrounding areas into a thallus (thallus: undifferentiated plant body lacking vascular tissue)

Phyla Bryophyta: Mosses

Nonvascular mosses that contain protonemata - branched filaments that are one cell thick that increase allotted surface area for water absorption

Phyla Anthocerophyta: Hornworts

Nonvascular plants recognized by their long and slender sporophyte structure

Moss Foot

Holds sporophyte to the top of the gametophyte

Moss Seta

The stalk that helps raise the sporangia above the gametophytes (and around) for spore dispersal

Capsule

Contains the sporangia

Moss Peristome

Where spores fall out of once wind knocks off the capsule cap and initiates reproduction

Seedless Vascular Plant Characteristics

1. Contains vascular system with xylem and phloem

2. Limited lignin production - true leaves and roots are present (megaphylls and microphylls)

3. No seeds, only spores

4. Independant gametophyte and sporophyte stages with dominant sporophyte stage

5. Obtain sporophylls

Sporophylls

Modified leaf that holds sporangia

Phyla Lychophyta: Club Mosses, quillwort, and spike mosses

Vascular (“fake”) mosses with microphyll leaves.

• Club mosses are homosporus, while spike mosses and quillworts are heterosporus

Phyla Monilophyta: Ferns, Horsetails, and Whisk Ferns

Nonvascular ferns that are homosprous and have megaphyll leaves.

Seed Composition

1. endosperm

2. plant embryo

3. protective outer coating

Ovule

When fertilized, this develops into a seed

Reduced Gametophyte Stage

All seeded plants have a dominant sporophyte stage that allows for a longer stage of sporangia production

Megasporangium

Diploid structure that gives rise to haploid female gametophytes in which only one of these structures can produce a singular megaspore

Microsporangium

Diploid structure that gives rise to haploid male gametophytes in which each of these structures gives rise to numerous microspores

Ovules

Composed of a megasporangium (2n), megaspore (n), and integument (2n) - once the egg is fertilized by sperm (which is housed in pollen), the development of this structure into a seed begins

Gymnosperm and Angiosperm Integument layers

Gymnosperm: 1

Angiosperm: 2

Pollen Grain

The next developing “destination” of a microspore

Sporopollenin

The composition of the protective layer that encloses the gametophyte

Pollination

The transfer of pollen seeds into the portion of the seed plant containing the ovule (germination occurs if contact with one another is successful and the pollen grain sprouts a pollen tube that extends to reach the ovule - reasoning for why sperm of seeded plants do not need to be motile)

Naked Seed

A term referring to the seed growth of gymnosperms - seeds are not enclosed within an ovary, but rather they develop on leaves or in scales (usually arranged as a cone)

Moniceous vs Dioecious

Male and female pine cones growing on a singular tree vs each cone being found on entirely different trees

Phylum Ginkophyta

Only one species of gymnosperms that retain flagellated sperm and are dioecious

Phylum Cycadophyta

Mostly tropical gymnosperms containing large cones, flagellated sperm, and over 350 species

Phylum Gnetophyta

Desert/tropical gymnosperms that obtain the largest leaves of all time

Phylum Coniferophyta

Most diverse group of gymnosperms with around 600 species - mostly evergreens like pines, firs, junipers, and woody cones

Angiosperm Characteristics

Most dominant terrestrial plant, seeds are contained within fruits that develop into reproductive structures called flowers, sporophyte dominant, and are composed of only one singular phylum: anthophyta

Flower

Specialized reproductive structures that help transfer pollen by attracting pollinators

Sepal

Modified leaf that encloses the flower before it blooms

Petal

Modified, brightly colored leaf that attracts pollinators

Stamen

The microsprorphylls composed of the anther and filament where microspores are produced and develop into pollen grains (filament is simply a stalk, while the anther is where pollen is produced)

Carpels

The container that encloses the seed - megasporophylls composed of the stigma, style, and ovary where megaspores are produced and develop into female gametophytes (the stigma receives pollen, the style connects the stigma to the ovary, and the ovary contains ovules)

Fruits after Fertilization

Following fertilization, the ovary wall begins to thicken and the ovules develop into seeds while the ovary develops into the fruit containing the seeds - maturation into a fruit

Micropyle

The opening in the integument of an ovule that allows a pollen tube to enter

Double Fertilization

Two sperm travel down the pollen tube, one fertilizes the egg cell and forms a diploid zygote, while the other fuses with two nuclei to form a triploid endosperm (protective coating)

Cotyledons

1 or 2 young leaves that develop within the embryo sporophyte

Monocots

Plant embryos containing a singular cotyledon and parallel vein systems

Eudicots

Plant embryos containing two cotyledons and web like vein systems

Fibrous Roots

Roots made up of many branched lateral roots that increase surface area (found in grasses and monocots)

Tap Root

Characterized by one main root structure that extends vertically downward (found in eudicots)

Internodes and Nodes

Stems and where the leaf attaches

Apical Meristem

Where plants elongate from - located at the apical bud

Axillary Bud

Located at the junction of stems and leaves

Petiole

Attaches the leaf to the stem

Blade

Portion of leaf where photosynthesis occurs

Palisade Mesophyll

Found underneath the upper epidermis in which it is responsible for photosynthesis

Spongy Mesophyll

Below the palisade mesophyll composed of many irregular shaped cells that form a maze of air pockets

Sclerenchyma Cells

Thick fibrous cells reinforced with lignin that provide additional support for the leaf (gritty)

Dermal Tissue

Provides the outer plant covering, composes the epidermis, cuticle, guard cells, and may form hair like structures called trichomes utilized for shading and reduction of water loss

Vascular Tissue

Made up of xylem, which transports water and minerals around the plant, and phloem, which moves products of photosynthesis around the plant

Ground Tissue

Supports and stabilizes plants - functions can include photosynthesis, support, and storage. Such tissue located on the inside of vascular tissue is called pith, while such tissue located on the outside of vascular tissue is called cortex

Parenchyma Cells

Thin and flexible cell walls containing large central vacuoles that function to store organic products, photosynthesize, and perform cellular respiration

Collenchyma Cells

Grouped in strands for flexible support with thicker cell walls

Xylem Cells

Water conducting cells that are dead and lignified when functional - may be tracheids (long, thin, and straw-like) or vessel elements (large diameter with perforation plates found at each cell end)

Phloem Cells

Living cells that conduct photosynthate - composed of sieve tube elements connected to companion cells via plasmodesmata (companion cells do not transport photosynthate)

Primary Growth

Apical Meristems providing cells that aid in elongation of a the plant

Secondary Growth

Exhibited by woody plants in which the lateral meristem contributes to the thickness of the plant

Vascular Cambium

Thin layer that produces secondary xylem and secondary phloem

Cork Cambium

Replaces the epidermis as the plant thickens - produces a tough thick covering (bark) to protect water loss

Root Cap

A protective covering on the apical meristem that secretes lubricating slime to allow for easy root elongation deep into the soil

Zone of Cell Division

Where new stem cells are produced - located at the root of the apical meristem

Zone of Elongation

Newly created root cells will lengthen

Zone of Differentiation

Before elongation is even completed and cells undergo differentiation to become distinct cell types

Protoderm

Portion of apical meristem that is composed of dermal tissue

Ground Meristem

Portion of the apical meristem that is composed of ground tissue

Procambium

Portion of the apical meristem that is composed of vascular tissue