Biology Plant Structure and Function Flashcards
Meristem cells
First cells when a plant embryo begins to develop
Apical meristems
Tissues located at the ends of a plant
Epidermal, ground, vascular
3 types of apical meristems
Epidermal tissue
forms the outer protective covering of a plant; cells exposed to air are covered by a waxy cuticle, restricting water loss and resists attacks from microorganisms.
Ground tissues
Fills the interior of a plant and helps carry out the functions of a particular organ; includes 3 types of simple tissues: parenchyma cells, collenchyma cells, sclerenchyma cells
Parenchyma cells
Type of simple ground tissue; has thin walls, are active in photosynthesis and storage
collenchyma cells
Type of simple ground tissue; provides support for primary tissues, has irregularly shaped corners and thicker cell walls.
sclerenchyma cells
Type of simple ground tissue; fibrous cells that give stalks their gravity-resisting strength.
Vascular tissue
Tissue that extends from the root through the stem to the leaves, and vice versa; 2 types of vascular tissues: xylem and phloem.
Xylem and Phloem
2 types of vascular tissue in vascular plants
Xylem
Type of vascular tissue in plants; transports water and minerals from roots to leaves; contains two types of conducting cells: vessel elements and tracheids.
vessel elements and tracheids
Two types of conducting cells in Xylem; dead at maturity, cell walls interconnect to form pipelines for water flow.
Phloem
Type of vascular tissue in plants; transports sugar, in the form of sucrose, and other organic compounds such as hormones, often from leaves to roots; conducting cells are called sieve-tube members and have a cluster of pores in their end walls collectively known as a sieve plate.
sieve tube members
The conducting cells of phloem; collectively known as a sieve plate; each one has a companion cell.
Shoot system
In above ground vascular plants; contains the stem, leaves, flowers, and fruits; anatomy consists of a lateral bud, node, internode, and terminal bud
Root system
the underground portion of a plant that anchors it in the soil and absorbs water and dissolved minerals; consists of root and root tip which also contains and apical meristem and produces primary growth downward.
perennial plants
Those that can outlast winter because their roots can survive to produce new shoots in spring.
Annual plants
Those that survive for one season only.
Monocots and Eudocots
2 major groups of flowering plants
cotyledons
Embryonic leaves present in seeds; the main difference between the 2 groups of flowering plants
Monocots
Plants whose embryos have one cotyledon; these cotyledons store some nutrients and act as a transfer tissue for nutrients stored elsewhere.
Eudicots (dicots)
Plants whose embryos have two cotyledons; these cotyledons supply nutrients for seedlings.
Leaves
chief organs of photosynthesis; composed of a blade attached to a peitiole, stalk that connects blade to stem.
Structures of leaves
Simple leaf-blade is undivided
Compound leaf-blade is divided
Mesophyll
Interior of a leaf; tissue that carries out photosynthesis and vascular tissue that transports water and minerals to the leaf and sugar out.
Palisade and spongy
2 distinct regions of mesophyll in a leaf
Palisade mesophyll
Contains elongated, tightly packed cells which increases the surface area for the absorption of sunlight.
Spongy mesophyll
Contains irregularly shaped cells surrounded by air spaces; loosely packed arrangement increases amount of surface area for gas exchange and water loss.
non-woody stems
Herbaceous plants that experience only primary growth (zinnias, mint, daisies); outermost layer is epidermis covered by cuticle; in eudicot stem, beneath epidermis is cortex and ground tissue in center is the pith; monocots stem lacks cortex and pith; xylem on inside of stem, phloem on outside
Cortex
Narrow bond of parenchyma cells beneath the epidermis in eudicot stems; sometimes green and carries on photosynthesis
Pith
Ground tissue in center of eudicot stem
Woody stems
Experiences both primary and secondary growth; vascular cambium forms ring of meristem that produces xylem & phloem each year
Bark
Contains cork, cork cambium, cortex, and phloem
Annual ring
Spring wood followed by summer wood
Roots
Support plant by anchoring in soil & absorbing water and minerals; have cylindrical shape and slimy surface
vascular cylinder
Consists of xylem and phloem; in eudicot root, xylem is star-shaped & phloem is in regions between points of star; in monocots root, xylem and phloem bundles alternate surrounding a pith
Endodermis
Controls passage of minerals into the vascular tissue; single layer of rectangular cells that fit snugly together
Pericycle
Can form lateral roots; first layer of cells inside endodermis
Root cortex
Contains starch granules; large thin-walled parenchyma cells
Root epidermis
Often has root hairs; outer layer of root
Nutrients
Elements essential for a given organisms growth and survival
Essential plant elements
Oxygen, hydrogen, carbon
Macronutrients
Nutrients required in greater amounts
Micronutrients
Nutrients that make up traces of a plant’s dry weight
Cofactors
Micronutrients; elements that ensure enzymes have correct shape
Root hairs, root nodules
Specialized adaptations that aid in uptake of water and nutrients in plants
Sand, silt, clay
3 textures of soil
Loams
Soils containing a mixture of clay, sand, silt, and humus. Good for growing most crops.
cohesion-tension model
A mechanism that describes how water and minerals travel upward in xylem cells
Transpiration
Evaporation of water from the leaves of a plant
90%
Amount of water taken up by root hairs and evaporating from leaves
turgor pressure
Force of water creating a bulge in a plant cell
Pressure-flow model
Explains how sugar is transported from source to sink
Source
Where sugar is made or stored
Sink
Where sugar will be used
Plant hormones
auxins, gibberellins, cytokinins, abscisic acid, ethylene; small organic molecules produced by a plant that serve as chemical signals between cells and tissue.
Auxins
Soften cell walls and allow growth; produced in the apical meristem located in terminal bud of shoot system and root tip; found in young leaves as well as flowers and fruits; inhibit lateral bud growth in vicinity of root tip, apical dominace, branches clipped to encourage bud growth; auxin moves from sunny side to shady side of plant during phototropism.
Apical dominace
The inhibition of the lateral buds by the apical meristem, which is caused by the large amount of auxin produced by the apical bud. Cutting the top meristem removes the inhibiting source of auxin (which controls the growth of the plant up/down) , which is why the lateral buds then grow.
Gibberellins
Growth-promoting hormones that are normally found in seeds; applied externally, they encourage dwarf plants to grow by elongating leaves and stems.
Cytokinins
Hormones that promote cell division; if applied to plants, they can prevent senescence and restore aging leaves, as well as encourage new leaf growth; in plant metabolism, they work interactively w/ auxins, given the relative acidity of the plant environment, to promote or slow down plant growth; correct ratio of this and auxin is best
abscisic acid (ABA)
Produced by any plant tissue that contains chloroplast as well as mono or endosperm and roots; called plant “stress” hormone bc it maintains the dormancy of seeds and buds and closes off stomata; closing off stomata is a specific response to water stress under drought conditions.
Etheylene
Gas that moves freely in air; works with other plant hormones to produce varying effects; some include hastening of fruit ripening (ripe fruits give off this gas) and abscision (falling off of leaves, fruits, or flowers)
Abscision
The falling off of leaves, fruits, or flowers from a plant.
alteration of generations
Alternation of production of sporophytes and gametophytes in the plant life cycle
Sporophytes
2n, spore-producing bodies that form in the vegetative body composed of roots, stems, leaves, and flowers
Gametophytes
n, gamete-producing bodies that form in the male and female flower parts; microspores and megaspores
Microspore
Female gametophyte, embryo sac
Megaspore
Male gametophyte, pollen grain
Sepal, petal
Non-fertile flower parts
Stamen, carpel
Fertile flower parts
Flower
Reproductive structure unique to angiosperms; produce spores and protect gametophytes; attract pollinators and produce fruits that enclose seeds
Sepal
Most leaflike of all flower parts; usually green but some resemble petals; protects the bud as flower develops
Petals
Non-fertile flower part; color accounts for attractiveness; size, shape, and color of these are attractive to specific pollinators
Stamen
Male portion of flower; has 2 parts: anther (sac-like container) and filament (slender stalk); haploid spores form in anthers and give rise to male gametophytes (pollen grain)
Carpel
Female portion of flower that has a vase like structure; has 3 parts: stigma (enlarged, sticky knob), style (slender stalk), and ovary (enlarged base enclosing one or more ovules); ovule becomes seed & ovary becomes fruit
Complete flowers
Those with both fertile and non-fertile parts
Incomplete flowers
Those without fertile and non-fertile parts
Bisexual flowers
Flowers that have both sexes (stamen and carpel).
Monoecious plants
Both male and female flowers are on one plant
dioecious plants
Male and female parts are on separate plants
Pollination
Transfer of pollen grains from an anther to a stigma; pollen grain germinates and develops into a pollen tube that grows down into the ovary, carrying the sperm nuclei with it
Double fertilization
Occurs when the sperm reaches the ovule; diploid zygote forms along with the nutritive tissue needed to sustain it (these form a seed)
Fruits
Develop from ovaries while seeds are forming; help protect and disperse the seeds.
asexual reproduction
Can be thought of as an alternative option in flowering plants; cells of nondifferentiated meristem tissue in plants routinely reproduce this way
Totipotent
Plant cells that can become an entire plant
Genetically Modified Plants (GMPs)
Transgenic plants; plant that’s had its DNA altered in some way; used to improve agriculture, food quality, and medicinal traits
Protection
What is the function of the root cap?
