plants Flashcards
lateral meristem that produces a tough protective covering for the surface of stems and roots.
cork cambium
lateral meristem that produces new xylem and phloem cells in the stem and roots.
vascular cambium
tough, protective layer of parenchyma cells that covers the tip of a root.
root cap
cells that control the opening and closing of the stomata; regulate the flow of water vapor from leaf tissue.
guard cells
nucleated cells that help transport sugars and other organic compounds through the sieve cells of the phloem.
companion cells
hollow, tubular cells in the xylem; conduct water and dissolve minerals from the roots to the stem; have open ends through which water passes freely from cell to cell.
vessel elements
anthophyte fertilization in which one sperm fertilizes the egg and the other sperm joins with the central cell.
double fertilization
in seed plants, structure in which the male gametophyte develops; consists of sperm cells, nutrients, and a protective outer covering.
pollen grain
regions of actively dividing cells near the tips of roots and stems; allows roots and stems to increase in length.
apical meristem
responsive movement of a plant not dependent on the direction of the stimulus.
nastic movement
two nuclei in the center of the egg sac of a flowering plant that become the triploid (3n) endosperm when joined with a sperm during double fertilization.
polar nuclei
plants that do not hav vascular tissues.
nonvascular plants
plants that drop all of their leaves each fall or when water is scarce or unavailable; an adaptation for reducing water loss when water is unavailable.
deciduous plants
plants that have vascular tissues; enables taller growth and survival on land.
vascular plants
type of asexual reproduction in plants where a new plant is produced from existing plant organs or parts of organs.
vegetative reproduction
tissues found in vascular plants composed of tubelike, elongated cells through which water, food, and other materials are transported throughout the plant; include xylem and phloem.
vascular tissues
tubular cells in phloem; each cell lacks a nucleus.
sieve tube members
a plant organ of seed plants consisting of an embryo, a food supply, and a protective coat; protects the embryo from drying out and also can aid in dispersal.
seed
anthophyte that has a life span of two years.
biennial
anthophyte that lives for one year or less.
annual
anthophyte that lives for several years.
perennial
any part of a plant that stores sugars produced during photosynthesis.
sink
beginning of the development of an embryo into a new plant.
germination
chemical produced in one part of an organism and transported to another part, where it causes a physiological change.
hormone
class of anthophytes that have one seed leaf.
monocotyledon
class of anthophytes that have two seed leaves.
dicotyledon
clusters of sporangia usually found on the surface of fern fronds.
sorus
compact cluster of sporebearing leaves produced by some non-seed vascular plants.
strobilus
plants that flower over a range in the number of daylight hours.
day-neutral plants
embryonic root of an anthophyte embryo; the first part of the young sporophyte to emerge during germination.
radicle
female reproductive organ of a flower.
pistil
female reproductive structure in which eggs develop.
archegonium
fern gametophyte.
prothallus
flowering plant response to differences in the length of day and night.
photoperiodism
food storage tissue in an anthophyte seed that supports development of the growing embryo.
endosperm
group of hormones that stimulate mitosis and cell division.
cytokinins
group of plant hormones that cause plants to grow taller by stimulating cell elongation.
gibberellins
growth response of a plant to an external stimulus.
tropism
hairlike projections that extend from a plant’s epidermis; help reduce water evaporation and may provide protection from herbivores.
trichomes
haploid spore formed by some plants that develops into a female gametophyte.
megaspore
haploid spore formed by some plants that develops into a male gametophyte.
microspore
in coniferophytes; scaly structures that support male and female reproductive structures.
cones
in ferns leaves that grow upward from the rhizome; often divided into pinnae that are attached to a central rachis.
frond
in mosses, a small, green filament of haploid cells that develops from a spore; develops into the gametophyte.
protonema
in plants, the bottom portion of a flower’s pistil that contains one or more ovules each containing one egg.
ovary
in plants, the layer of cells just within the endodermis that gives rise to lateral roots.
pericycle
in plants, the loss of water through stomata.
transpiration
in plants, the outmost layer of flattened cells that covers and protects all parts of the plant.
epidermis
in plants, the stalk that joins the leaf blade to the stem.
petiole
in seed plants, the sporophyte structure surrounding the developing female gametophyte; forms the seed after fertilization.
ovule
layer of ground tissue in the roots that is involved in the transport of water and ions inot the vascular tissue of the root.
cortex
leaflike flower organs, usually brightly colored structures at the top of a flower stem.
petals
leaflike, usually green structures encircle the top of a flower stem below the petals.
sepals
long, flexible plant cells with unevenly thickened cell walls; most common in actively growing tissues.
collenchyma
plants that are induced to flower when the number of daylight hours is longer than its critical period.
long-day plants
male reproductive organ of a flower consisting of an anther and a filament.
stamen
male reproductive structure in which sperm develops.
antheridium
most abundant type of plant cell; spherical cells with thin, flexible cell walls and a large central vocuole; important for storage and food production.
parenchyma
movement of sugars in the phloem of a plant.
translocation
openings in leaf tissues that control gas exchange.
stomata
period of inactivity in a mature seed prior to germination.
dormancy
photosynthetic tissue of a leaf.
mesophyll
plant cells with thick, rigid cell walls; provide support for the plant and are a major component of vascular tissue.
sclerenchyma
plant hormone that promotes the ripening of fruits.
ethylene
plant organ that absorbs water and minerals usually from soil; conatins vascular tissues; anchors plants; can be a storage organ.
root
plant organ that provides support and growth; contains tissues that transport food, water, and other materials; organ from which leaves grow.
stem
pollen-producing structure located at the tip of a flower’s stamen.
anther
portion of the stem nearest the seed in a young plant.
hypocotyl
protective, waxy coating on the outer surface of the epidermis of most stems and leaves; important adaptation in reducing water loss.
cuticle
regions of actively dividing cells in plants.
meristems
seed-containing ripened ovary of an anthophyte flower; may be fleshy or dry.
fruit
a plant that is induced to flower when the number of daylight hours is shorter than its critical period.
short-day plant
single layer of cells that forms a waterproof seal around a root’s vascular tissue; controls the flow of water and dissolved minerals into the root.
endodermis
structure of seed plant embryo that stores or absorbs food for the developing embryo.
cotyledons
the opening in the ovule through which the pollen tube enters.
micropyle
the plant organ that grows from a stem in which photosynthesis usually occurs.
leaf
the young diploid sporophyte of a plant.
embryo
thick, underground stem of a fern and other vascular plants; often functions as an organ for food storage.
rhizome
tubular cells in the xylem that have tapered ends and are dead at maturity.
tracheids
vascular plant tissue composed of tubular cells that transport water and dissolved minerals from the roots to the rest of the plant.
xylem
vascular plant tissue made up of tubular cells joined end to end; transports sugars to all parts of the plant.
phloem
