Biology Lab Plants 2

Osmosis

the diffusion of water across a semipermeable membrane
Water diffuses from high water concentration to low water concentration

Water potential

the physical property based on the solute concentration of a solution and the pressure within a given space that determines the direction of water movement across a differentially permeable membrane

Cohesion

the intermolecular bonding of like molecules (water to water)

Adhesion

the attraction of one type of molecule to a different type (water to cellulose molecules, cells wall)

Surface tension

a measure of how diffiult it is to break the surface of a liquid

Capillary action

the depression or elevation of the surface of a liquid where it contacts a solid surface, for example, the sides of small tubes

Meniscus

liquid rises up the sides of the tube creating a crescent shaped body
Concave: adhesion > cohesion
Convex: adhesion < cohesion

Casparian strip

walls of the endodermal cells containing a waxy layer of suberin, effectively sealing off the apoplast route of entry into the stele; can only pass through symplast of endodermis

Root pressure

upward push of fluid sap (due to buildup of water causing fluid to rise in the xylem)

Transpiration

evaporation of water from leaves
Negative pressure leads to pull of water and nutrients up the xylem

What do guard cells do?

Guard cells control the sides of the stomata and help to keep a balance between the needs of water conservation and photosynthesis

Sporophyte

the multicellular, diploid form of an angiosperm plant which results from the union of haploid male and female gametes and, at maturity, is capable of meiotically producing haploid spores

Gametophyte

the multicellular, haploid form of an angiosperm plant that mitotically produces haploid male and female gametes

Flower

a complete reproductive structure formed by the transition of a vegetative apical meristem to a floral meristem in the terminal bud of a stem, whose leaves differentiate to form its organs; sepals, petals, stamens, and carpels

Stamens and carpels

Stamens are the male reproductive organs of the plant
Carpels are the female reproductive organs of the plant

Petals and sepals

are leaves (nonproductive organs) used to attract pollinators and to protect the reproductive structures

Receptacle

four floral organs are attached to the shoot (stem) by the receptacle

Ovary

in flowering plants, the portion of the female reproductive organ (carpel) that contains one or more ovules that house the female gametophyte

Style

the stalk of the female reproductive organ (carpel) situated between the ovary at its base and the stigma at its top

Stigma

receives pollen

Seed coat

the protective outer covering of a seed formed from the outer coat of an ovule within the ovary of a flowering plant, which encapsulates the embryo and endosperm

Hilum

a layer of scar tissue located on the side of the bean

Cotyledons

embryonic seed leaves that absorb and transfer the food reserves of the endosperm to the germinating embryonic plant

Hypocotyl

the region of the shoot below the point of attachment

Radicle

the root on an embryonic, angiosperm plant

Epicotyl

the region of the shoot above the point of cotyledon attachment

Plumule

the shoot tip with the first pair of foliage leaves at the end of the epicotyl

Scutellum

the name given to the cotyledon of certain monocot grass seeds such as wheat

Endosperm

the tissue of the scutellum absorbs and transfers the food reserves storied in the endosperm to the developing plant

Coleoptile

small plumules encased in a protective sheath

Coleorhiza

the radicle is covered by its own protective layer

Tropisms

movements that are produced by differential growth in a plant in response to external stimuli

Positive Phototropism

the growth of a shoot towards a light source

Negative Gravitropism

upward growth of a shoot placed on its side