Microfilaments

A component of the cytoskeleton. Polar structures with a plus and a minus end, composed of actin proteins. 5 - 7 nm in diameter. Some are associated with microtubules. Assembled at certain points in the cell. Occur in bundles in many plant cells. Involved in cell wall deposition, tip growth of pollen tubes, movement of the nucleus during cell division, organelle movement, vesical-mediated secretion, organization of the ER, and cytoplasmic streaming.

Horse chestnut

Does not flower until it is about 25 years old.

Pneumatophores

Roots that grow out of water to aerate the root system. Found in plants that grow in swampy habitats.

Strasburger cells

A parenchyma cell which associates with sieve cells of gymnosperms, and performs a role similar to companion cells: keeps the sieve cell alive.

Corpse plant

Blooms once every 10 years. Smells like rotting flesh to attract flies. Has a spadix flower.

Granit moss

A genera of Andreaeidae. 100 species of small, blackish-green or dark reddish brown tufted moss which often grow on granite rocks. The protonema and rhizoids hhave two or more rows of cells, rather than one. Capsules are lined by four lines of weaker cells which are split and are sensitive to humidity, opening when dry so that spores are carried away by the wind.

Granite moss

A class of moss. There are two genera: Andeaea and Andreaeobryum.

"House of man"

Side branches with modified leaves that hold the antheridia of leafy liverworts.

The stamens of a flower.

"Seed vessel"

Flowering plants

A member of spermatophytes. Dominant on earth, and extremely diverse. The gametophyte generation is very reduced. Non-motile sperm are delivered to the egg by the pollen tube. Includes monocots and eudicots. Appeared very suddenly 135 million years ago. Evolved from gnetophytes, but actually gymnosperms and angiosperms are monophyletic.

Sweet, highly coloured fleshy fruits co-evolved with animals; the majority of fleshy fruits are eaten by vertebrates and the seeds are dispersed by being passed through the digestive tract or being regurgitated. Sometiems partial digestion aids in germination. As the fleshy fruit ripens, it undergoes a rise in sugar, softening, and change in colour.

Many fruits are dispersed by adhering to the fur or feathers of animals. Fruits and/or seeds have hooks, barbs, spines, hairs, or sticky coverings that allow them to be transported attached to the bodies of animals.

Ants disperse with elaiosomes and eat the elaiosome. Up to a third of plant species in some communities are dispersed by ants.

Hornworts

Bryophytes. Some are thalloid. More than 300 species. They have horn-shaped sporophytes. The gametophytes resemble thalloid liverworts. Cells have a single large chloroplast with a pyrenoid or many chloroplasts and no pyrenoid. The gametophyte is rosette-shaped with dichotomous branching, usually 1 - 2 cm across, without conspicuous internal differentiation. There are large cavities containing colonies of Nostoc, embedded in mucilage, where they fix nitrogen for the hornwort. Pores on the lower epidermis are entry sites for Nostoc. Many cells secrete mucilage for water retention. Some hornworts have associations with glomeromycetes. Most hornworts are unisexual. Gametangia are on the dorsal surface of the gametophyte, with antheridia clustered in chambers. Many sporophytes may form from the same gametophyte. Includes Anthoceros.

Snapdragons

A model organism for studying homeotic genes.

"Ancient ones"

A domain of life. Thrive in extremely hot or acidic environments which are hostile to other organisms.

Vegetative reproduction

Produces progeny that are genetically identical to the single parent. Meiosis and fertilization are absent. There is a wide variety of means of asexual reproduction. Many plants produce both sexually and asexually. Plants who reproduce only asexually had sexually reproducing ancestors. Requires less energy than sexual reproduction. Provides means to reproduce in the absence of mating. Allows for exact replications of individual well-suited to a certain environment. Populations cannot adjust to changing conditions as rapidly as sexually reproducing species. Mutations are always passed on to offspring. If a new disease arises, the entire population can be affected.

Composites

Eudicots. One of the most specialized and numerous families of flowers. Each flower has two fused carpels with a single ovule in one locule. Five stamens, fused to one another and to the corolla. Five petals are fused to one another and to the inferior ovary. Sepals are absent or reduced to bristles/scales, and may have a pappus. Each composite flower consists of disk flowers in the centre and ray flowers in the periphery. The composite head appears to be one flower. Each true flower matures at a different time, increasing genetic diversity; many pollination events occur.

"Self feeder"

Satisfy energy requirements by producing their own complex organic compounds (including carbohydrates, fats, and proteins) from simple inorganic molecules. Typically use energy from sunlight to produce organic compounds using photosynthesis. Provide complex organic compounds for all heterotrophs.

Betalains

Pigments in flowers composed of complex aromatic compounds that produce reddish pigment. Occurs in plants which cannot produce anthocyanins. Example: peets, Bougainvillea.

Irregular flowers

Zygomorphic: "yolk", "pair"

One or more members of at least one whorl are different from other members of that same whorl. Some have irregular colour patterns. Example: snapdragons, garden peas.

"Two-term"

A system for naming species. The first term is the genus, and the second term is the specific epithet.

Lamina

The exposed portion of a leaf.

Shepherd's tree

The plant with the deepest roots: 68 m deep. Lives in teh Kalahari Desert.

True moss

A class of moss; most moss species. The protonema has branching filaments with single rows of cells. Leafy gametophytes develop from budlike structures on the protonema. In some species the protonema is the dominant form. The gametophyte can be up to 50 cm in length. Has mutlicellular rhizoids, leaves one cell thick (except at the midrib). Some species have hadrom and leptom.

Gametangia are on the tip of the main axis or on a lateral branch. Some genera are unisexual, some bisexual. Several antheridia are often on a single leafy structure called the splash cup.Insects may carry sperm-laden water from plant to plant.

Sporophytes take 6 - 18 months to mature, and are elevated on seta which can be up to 20 cm long, and can have hadrom and leptom. Some are brightly coloured to attract insects. Stomata are present on the sporophyte; some species have just one doughnut-shaped guard cell. The young sporophyte is photosynthetic, but when it matures it becomes yellow, orange, then brown. When mature the calyptra and operculum burst off, revealing the peristome and dispersing spores.

Reproduces aseuxally by fragmentation or with specialized features.

Many species are endemic to an area, and have species which live, breed, and feed off of it. Loss of Bryidae species could be catastrophic.

There are cushiony and feathery mosses.

Mosses

Bryophytes

Many non-moss species are called "moss". Mosses have five classes: Sphagnidae, Andreaeidae, Bryidae.

Nonvascular plants

A paraphyletic group including Bryophyta, Marchantiophyta, and Anthocerotophyta. Small, leafy, or flat plants. Cells are not lignified, and are connecte dby plasmodesmata. Have disk-shaped plastids. Limited to growing in moist locations because they lack vascular tissues. Often found in temperate or tropical forests, or along the edge of wetlands or streams, however they are not confined to such habitats.

The gametophytes are larger than the sporophytes, and free-living. Bryophytes have pores and rhizoids. Marhcntiophyta and Anthocerotophyta are thalloid.

Sporophytes are smaller and permanently attached to, and dependent on, the parental gametophyte.

Many bryophytes can reproduce asexually by fragmentation.

Reproduce sexually by gametic meiosis. Gametes are produced by antheridia and archegonia. Some species are unisexual and some are bisexual.

Significant in the ecosystem and carbon cycle, and important initial colonizers of bare rock and soil substrates.

Motor cells

Occur in longitudinal rows in the epidermis of some grasses. Participate in the mechanism of folding and unfolding of leaves in response to changes in water potential. Become flaccid with water loss, folding the leaf.

Lignotubers

Woody outgrowths at the base of the stems of shrubs and small trees in the Mediterranean type of climate of the Californian chaparrals. Contain dormant buds that sprout after the shoots are mechanically damaged or burned.

"I carry coal"

300 - 400 million years ago

There was huge climate change. Lepidodendron dominated hot, humid swamps, and contributed to development of coal deposits. CO₂ levels in the atmosphere decreased due to Lepidodendron. Humidity decreased, and swamps dried up, killing Lepidodendron and beginning the Ice Age.

1701 - 1778

In 1783, he published Specis Planatarum. Created the binomial system.

Pistillate

Imperfect flowers with carpels.

Grain

An indehiscent, dry simple fruit. The seed coat is fused to the pericarp over its entire surface.

M phase

The second phase of cell cycle. Cells reproduce. The contents of a cell are divided between two daughter cells. The means by which single-celled organisms reproduce, and by which multi-cellular organisms grow and replace injured or worn out tissues. Has two phases: mitosis and cytokinesis.

Stonewort

A group within Charales. Has calcified cell walls. Sperm are produced by antheridia. Eggs stay enclosed in oogonia. The sperm are the only flagellated cells in their life cycle. Zygotes are encased in sporopollenin.

Wrote On the Origin of the Species. 

"Probably all of the organic beings that ever lived on this earth have descended from some one primordial form, into which life was first breathed."

Charophyte algae

Streptophyte algae

Charophytes

Unicellular, colonial, filamentous, and parenchymatous genera. Have similarities to bryophytes and vascular plants. All have zygotic meiosis. Divergent members include Mesostigma, Chlorokybus, Klebsormidium, and Spirogyra.

Plural, chiasmata

The point in the synaptonemal complex of homologous chromosomes where crossing-over occurs during prophase I. It makes an X-shpaed configuration. At least one chiasma appears.

Chlorophytes

A class of algae. Flagellated and non-flagellated, unicellular and multi-cellular, motile, non-motile, colonial, filamentous, and in flat sheets. Mainly live in freshwater, but there are some marine species. Includes snow algae. Have zygotic meiosis. Includes Chlamydomonas, Volvox, Chlorococcum, Hydrodictyon, Oedogonium, and Fritschiella.

"Colour"

A plastid. Pigmented plastids. Lack chlorophyll, but synthesize and retain carotenoid pigments. Found in flowers, aging leaves, fruits, and roots. May develop from chloroplasts when chlorophyll disappears, such as in the ripening of fruits. Helps the plant attract animals with which the plant has co-evolved (for pollination or seed dispersal).

Singular, cilium

Short, hair-like structures in great numbers on the surface of some cells. Have movement similar in mechanism to that of a flagellum. Grow from basal bodies in the cytoplasm.

Singular, cisterna

Flattened sacs of membrane in the rough ER, or in the Golgi bodies. In the Golgi body, subsequent steps in synthesis occur in each cisterna.

Lycopodiophyta

A member of lycophytes.

CLAVATA

The gene that regulates meristem size by repressing initial cell activity. Loss of CLV genes causes accumulation of undifferentiated cells in the central zone, increasing the size of the meristem. Includes CLV1, CLV2, and CLV3.

Sib cell

A parenchyma cell that contains all cell components including the nucleus. Closely associates with a sieve tube element with numerous plasmodesmata. Deliver substances to the sieve tube element to keep it alive: information molecules, proteins, ATP.

Phellem

A tissue of the periderm. Non-living at maturity. Dead at maturity, and walls are heavily suberized. Arises from the outer surface of the cork cambium. Highly impermeable to water and gasses.

Phellogen

A tissue of the periderm. A lateral meristem. Forms cork on the outer surface, and phelloderm on the inner surface. Origin is variable.

CO1

Genes that encode for cytochrome oxidase 1. Present in the mitochondria of all animals. Used as a universal DNA barcode for animals. Varies wildly between species, but rarely between individuals of one species. Not suitable as a barcode for plants.

Singular, crista

Folds or tubules in the inner membrane of a mitochondrion, which increase the surface area available to proteins. Encloses the matrix.

Cyclosis

The constant motion of the cytoplasm as long as the cell is alive. Facilitates transport of materials within the cell and into/out of its environment. Mediated by actin filaments.

Cytoplasmic matrix

A component of the cytoplasm. The cellular "soup": the fluid in which other cytoplasm contents float.

"Two houses"

When staminate and carpellate flowers are on different plants.

"Double set"

With two copies of genes.

A homeotic mutation that results in petals forming instead of stamens.

Example: garden roses. Wild-type roses have 5 petals, and the double flwoer mutation has 20 or more.

Stone fruit

A fleshy simple fruit. Generally has one seed. A thin, skin-like exocarp, fleshy mesocarp, and stony endocarp that encloses the seed.

Example: peach, cherry, olive, plum. A coconut is a drupe with a fibrous mesocarp.

"Originating within"

Originating from deep within the parent root. Lateral roots are endogenous.

Endoreplication

Replication of DNA before differentiation. May occur more than once, resulting in large nuclei with multiple copies of each gene.

Postulated in 1910 by Konstantin Mereschkowski. Explains the transformation of prokaryotic cells into eukaryotic cells.

Prokaryotes first lost the cell wall, becoming phagocytes. Sterols were incorporated into the plasma membrane, making it flexible. This allowed for the development of membrane-bound inner organelles and the nucleus. A cytoskeleton developed to provide support and aid in movement of hte cell and its internal components.

The phagocyte then enculfed smaller cells: alpha-proteobacterium and cyanobacteria, which lost unnecessary structures, transfered most of their DNA to the host, and became mitochondria and chloroplasts, respectively.

Evidence for this: mitochondria and chloroplasts have double membranes. The inner membrane originates from the original free-living bacteria, and the outer membrane originates from the plasma membrane of the host.

Cuticle

A mixture of cutin and wax, deposited on the epidermis in smooth sheets or in a rod/filament style extending upwards.

Horsetails

A member of pterophytes. A phyla of seedless vascular plants that dominated from the Late Devonian period through the Carboniferous Period. Today there is only one genus: Equisetum. Have vegetative shoots, and reproductive shoots with cone-like strobili. Stems arise from rhizomes that bear wiry roots. Sporangia contract and split along the inner surface, elaters coil and uncoil, helping to disperse spores.

Dicots

Dicotyledons

A classification of angiosperms. Flowers are in multiples of four or five. Triaperturate: has three pores or furrows on the pollen. Two cotyledons. Usually netted leaf venation. Vascular bundles in the stem are arranged in a ring, with pith. Secondary growth with vascular cambium is common.

A domain of life. Contains eukaryotes. There are an estimated 10 million eukaryotic species. All organisms except bacteria and archaea are eukaryotes.

There are three kingdoms within Eukarya: Fungi, Animalia, and Plantae.

Feeder roots

The roots most actively engaged in the uptake of water and minerals. Occurs in the upper 15 cm of the soil, usually the richest in nutrients. Generally short lived; lasts a few months. About 33% of productivity in terrestrial ecosystems is production of fine roots.

Sinular, flagellum

A long, hair-like structure extending from the surface of many types of eukaryotic cells, about 0.2 μm in diameter. Propels the organism through water. In plants, only found on the gametes of plants with motile sperm: mosses, liverworts, ferns, cycads, and Gingko trees.

Capable of movement even when detached from the cell; movement is produced by sliding microtubule mechanisms where the outer pairs of microtubules move past one another without contracting, causing localized bending of the flagellum. Cycles of attachment and detachment between neighboring pairs in the outer ring produces regular movement. Grow from basal bodies in the cytoplasm.

"Gate-keepers"

One of the forms of non-dispersive P protein bodies. Expanded. Seals sieve tubes.

Vegetative propagation

A method of asexual reproduction in bryophytes. Small pieces of tissue are separated and develop into entire, new gametes.

Gap phase 1

The first stage of interphase. The cell wall ruptures as the cell enlarges. Intense biochemical activity. There is a checkpoint at the end of G₁: either initiates S phase or enters G₀ phase. Centriole and centrosomes are duplicated. The nucleus moves to the centre of the cell, and cytoplasmic strands anchor it within the tonoplast, forming the phragosome.

Gap phase 2

Checks that chromosome duplication is complete and any mistakes have been replaced. Centriole duplication is completed. The preprophase band appears. Chromosomes begin to condense. There is a checkpoint at the end of G₂; either arrests or goes through with mitosis.

Phaseolus vulgaris

A eudicot with epigeous germination. Food is stored in the cotyledons of the seed.

One of the cells in a gymnosperm pollen grain.

In angiosperms, the smaller cell formed in two-celled stage of microgametogenesis. Divides to form the sperm cells in three-celled stage.

Plural, genera

The category below family and above species. The first term in the binomial system. May be written by itself.

GLABROUS2

Activated early in development of protoderm cells.

Golgi stacks

Golgi dictysomes

Five to eight stacks of cisternae, often branched into complex series of tubules at the margins. Has two poles: cis face and trans face. Plants have many separate Golgi bodies. Different steps of protduction occur sequentially in each cisternae. Synthesize non-cellulose polysaccharides for the cell wall. Transform ER type membranes into vesicle type membranes. Transition vesicles deliver glycoproteins from the ER. Shuttle vesicles carry glycoproteins to subsequent cisternae. Coated vesicles package newly formed proteins.

Singular, granum

Thylakoid complexes in chloroplasts. The thylakoids are connected by stroma thylakoids.