Test 2 Biology Flashcards
Extracellular route
Via cell walls spaces between cells; stopped by Casparian strip.
Intracellular route
via cell interiors, through plasmodesmata
Casparian strip
a waxy barrier in the walls of endodermal cells in a plant root that prevents water and ions from entering the xylem without crossing one or more cell membranes.
plasmodesmata
an open channel in a plant cell wall that connects the cytoplasm of adjacent cells
monocot
one cotyledon, veins usually parallel, vascular tissue scattered in a complex arrangement, floral parts usually in multiples of three, fibrous root system.
eudicots
two cotyledons, veins usually branched, vascular tissue usually arranged in rings, floral parts usually in multiples of four or five, taproot usually present.
cotyledons
the first leaf that appears on an embryo of a flowering plant; a seed leaf.
root epidermal cell
a cell in the outer layer of the root.
shoot system
stems, leaves, and structures for reproduction (flowers for angiosperms)
nodes
points at which leaves are attached to the stem
internodes
the portions of the stem between the nodes
buds
undeveloped shoots
terminal buds
when a plant is growing in length, the terminal bud at the apex (tip) of the stem has developing leaves and a compact series of nodes and internodes.
axillary buds
one in each of the crooks formed bay a leaf and the stem, are usually dormant.
apical dominance
terminal buds produce a hormone that inhibits the growth of axillary buds
stolon
enable the lant to reproduce asexually as plantlets form at nodes along their length.
rhizomes
a horizontal stem of a plant that grows below the ground (ginger, iris plant).
tendrils
helping vine that clings to solid structures (peas and grapes)
three plant tissue systems
dermal, vascular, and ground
dermal tissue system
the plant outer layer (protective)
vascular tissue system
made up of xylem and phloem tissues and provides support and long-distance transport between the root and the shoot system.
ground tissue system
filling space between dermal and vascular tissue. pith inside of vascular. cortex outside of vascular tissue. look at figure 31.5 if confused.
endodermis
on cell thick barrier, regulate what goes in and out the vascular cylinder.
tubers
an enlargement at the end of a rhizome in which food is stored (potato).
guard cell
a specialized epidermal cell in plants that regulates the size of a stoma, allowing gas exchange between the surrounding air and the photosynthetic cells in the leaf.
mesophyll
leaf cells specialized for photosynthesis; a leaf’s ground tissue system.
vein
vascular bundle composed of xylem and phloem tissues surrounded by a protective sheath of cells
parenchyma cells
in plants, a relatively unspecialized cell with a thin primary wall and no secondary wall; functions in photosynthesis, food storage, and aerobic respiration.
- most active
- cell walls- cellulose
- pith
collenchyma cells
In plants, a cell wall with a thick primary wall and no secondary wall, functioning mainly in supporting growing parts. (celery stalk string)
- flexible support
- growing parts
- outer
sclerenchyma cell
In plants, a supportive cell with rigid secondary walls hardened with lignin. there are two types of sclerenchyma cells
- protective and support
- cell walls with lignin and cellulose
sclereid
In plants, a very hard sclerenchyma cell found in nutshells and seed coats.
fiber
in plants, a long slender sclerenchyma cell that usually occurs in a bundle.
companion cell
in a plant, a cell connected to a sieve-tube element whose nucleus and ribosome provide proteins for the sieve-tube element
sieve plate
an end wall in a sieve tube element that facilitates the flow of phloem sap
sieve tube element
a food conducting cell in a plant; also called a sieve tube member. chains of sieve tube elements make up phloem tissue.
tracheid
thin and long, a tapered, porous, water-conducting, and supportive cell in plants. chains of tracheid of vessel elements make up the water-conducting, supportive tubers in the xylem
vessel element
wide, a short, open-ended, water-conducting, and supportive cell in a plant.
phototropism
the growth of a plant organ toward the light (positive phototropism) or away from the light (negative phototropism)
tropism
a growth response that makes a plant grow toward or away from a stimulus.
hormone
in plants, a chemical that is produced in one part of the plant and travels to another part, where it acts on targets cells to change their functioning.
auxins (major function)
stimulate stem elongation; affect the root growth, differentiation, branching; development of fruit; apical dominance; phototropism and gravitropism; retard leaf abscission.
auxins (where produced or found)
meristem of apical buds, young leaves, developing seeds, and fruits.
cytokinins (major function)
affect root growth and differentiation; stimulate cell division and growth; stimulate germination; delay leaf aging.
cytokinins (where produced or found)
made in roots and transported to other organs.
gibberellins (major functions)
promote bud, stem elongation, and leaf growth; stimulate flowering, fruit developing, and seed germination
gibberellins (where produced or found)
meristems of apical buds and roots, young leaves, and developing seeds
abscisic acid (major function)
inhabits growth; closes stomata during dry spells; helps maintain seed dormancy; promotes leaf aging.
abscisic acid (where produced or found)
every major organ: leaf, stem, roots, fruits
ethylene (major functions)
promotes fruit ripening and leaf abscission; opposes some auxin effects; promotes root formation; promotes flowers in some species
ethylene (where produced or found)
ripening fruits, nodes of stems, aging leaves, and flowers, and wounds
abscission layer
the region where separation occurs [trees and leaves]
petiole
joins the to a node of the stem
pith
part of the ground tissue system of a dicot plant. pith fills the center of the stem and may store food.
lamella
The primary [cell] wall of adjacent cells in plant tissue is held together by a sticky layer called lamella.
pit
where the cell wall is thin and allows water to migrate between adjacent cells.
annuals
a plant that completes its life cycle in a single year or growing season
biennial
a plant that completes its life in two years.
perennial
a plant that lives many years
meristem
plant tissue consisting of undifferentiated cells that divide and generate new cells and tissue.
apical meristem
a growth-producing region of cell division consisting of undifferentiated cells cell located at the tip of a plant root or in the terminal or axillary bud of a shoot.
primary growth
growth in length of a plant root or shoot, produced by an apical meristem
root cap
a cone at the tip of a plant root that protects the root’s apical meristem.
lateral meristem
plant tissue made up of undifferentiated cells that in able roots and shoots of woody plants to thicken. the vascular cambium and cork cambium are lateral meristem.
vascular cambium
during the secondary growth of a plant, the cylinder of meristem cells, surrounding the xylem and pith, produces secondary xylem and phleom.
wood
secondary xylem of a plant
cork
the outermost protective layer of a plant’s bark, produced by the cork cambium
cork cambium
meristematic tissue that produces cork calls during the secondary growth of a plant.
bark
all the tissues external to the vascular cambium in a plant that is growing in thickness. The bark is made up of secondary phloem, cork cambium, and cork
wood rays
a column of parenchyma calls that radiates from the center of a log and transports water to its outer living tissues.
sapwood
light-colored, water-conducting secondary xylem in a tree
heartwood
in the center of trees, the darkened, older layers of secondary xylem made up of cells that no longer transport water and are clogged with resin.
double fertilization
in flowering plants, the formation of both a zygote and a cell with. a triploid nucleus, which develops in the endosperm.
fragmentation
a means of asexual reproduction whereby a single parent breaks into parts that regenerate into whole new individuals.
how does a guard cell become turgid?
accepting K+ and water (opens stroma)
sugar source
is a plant organ that is a net producer of sugar by photosynthesis or by the breakdown of starch. Primary in leaves
sugar sink
is an organ that is a net consumer or storer of sugar. growing roots, stems, and fruits are sugar links.
nitrogen-fixing bacteria
makes NH+ from the soil and atmosphere
ammonifying bacteria
gets NH+ from organic, material
nitrifying bacteria
gets NO- from weathering rocks
epiphyte
produce their own food and absorb water and minerals from rain
photoperiod
the relative lengths of day and night; an environmental stimulus that plants use to detect the time of year
phytochromes
PROTEINS WITH A light-absorbing competent
