35 Chapter Flashcards
Fractals
Repetitive patterns
Angiosperms
Flowering plants
Two main groups of flowering plants
Eudicots
Monocots
Organ
Consists of several types of tissues that together carry out particular functions.
Tissue
A group of cells, consisting of one or more cell types that together perform a specialized function.
Vegetative growth
Production of leaves, stems, and roots
Photosynthates
The sugars and the other carbohydrates produced during photosynthesis.
Roots depend on _____
Photosynthates
The shoot system depends on ________
The water and minerals that roots absorb from the soil.
Root system
All of a plant’s roots, which anchor it in the soil.
Absorb and transport minerals and water, and store food.
Root
An organ that anchors a vascular plant in the soil, absorbs minerals and water, and often stores carbohydrates and other reserves.
Primary root
Originating in the seed embryo, is the first root (and the first organ) to emerge from a germinating seed.
Lateral roots
Is formed when the primary root branches out.
Greatly enhances the ability of the root system to anchor the plant and to acquire resources such as water and minerals from the soil.
Tall, erect plants with large shoot masses generally have a ________
Taproot system
Taproot
Usually develops from the primary root and helps prevent the plant from toppling.
Fibrous root system
A thick mat of slender roots spreading out below the soil surface.
-Usually in small plants
Adventitious
A term describing a plant organ that grows from an unusual source, such as roots arising from stems or leaves.
Root hairs
Thin, finger-like extensions of root epidermal cells.
Increase the surface area of the root enormously.
Mycorrhizal associations
Symbiotic interactions with soil fungi that increase a plant’s ability to absorb minerals.
Stem
A plant organ bearing leaves and buds.
Stem main function
To elongate and orient the shoot in a way that maximizes photosynthesis by the leaves.
Another function of stems is to elevate reproductive structures, thereby facilitating the dispersal of pollen and fruit.
True
Nodes
The points at which leaves are attached.
Internodes
The stem segments between nodes.
Apical bud
A bud at the tip of a plant stem; also called a terminal bud.
Axillary bud
A structure that has the potential to form a lateral shoot, or branch. The bud appears in the angle formed between a leaf and a stem.
Examples of modified stems
Rhizomes
Stolons
Tubers
Leaf
Main photosynthetic organ in most vascular plants.
A leaf consists of…
A flattened blade and a stalk, the petiole.
Petiole
Joins the leaf to the stem at a node.
Grasses and many other monocots lack petioles; instead the base of the leaf forms a sheath that envelops the stem.
True
Veins
The vascular tissues of leaves
Most monocots have parallel major veins of equal diameter that run the length of the blade.
True
Eudicots generally have a branched network of veins arising from a major vein (the midrib) that runs down the center of the blade.
True
Simple leaf
Has a single undivided blade.
Compound leaf
The blade consists of multiple leaflets. A leaflet has no axillary bud at its base.
All three basic plant organs—roots, stems and leaves—are composed of dermal, vascular, and ground tissues.
True
Each tissue type forms a tissue system that connects all of the plant’s organs.
True
Dermal tissue system
The plant’s outer protective covering. Forms the first line of defend against physical damage and pathogens.
Epidermis
Example of a Dermal tissue system. A layer of tightly packed cells.
Cuticle
A waxy epidermal coating, helps prevent water loss in leaves and most stems.
Periderm
Replace the epidermis in older regions of stems and roots in woody plants.
The epidermis has specialized characteristics in each organ.
The chief functions of the vascular tissue system are to…
Facilitate the transport of materials through the plant and to provide mechanical support.
Two types of vascular tissues
Xylem
Phloem
Xylem
Conducts water and dissolved minerals upward from roots into the shoots.
Phloem
Transports sugars, the product of photosynthesis, from where they are made (usually the leaves) to where they are needed—usually roots and sites of growth, such as developing leaves and fruits.
The vascular tissue of a root or stem is collectively called the _____
stele
The arrangement of the stele varies, depending on the species and organ.
True
In angiosperms, the root stele is a solid central _________ of xylem and phloem, whereas the stele of stems and leaves consists of _______, separate strands containing xylem and phloem.
Vascular cylinder, vascular bundles
Tissues that are neither dermal nor vascular are part of the ___________
Ground tissue system
Pith
Ground tissue that is internal to the vascular tissue
Cortex
Ground tissue that is external to the vascular tissue
Mature parenchyma cells have primary walls that are relatively thin and flexible, and most lack secondary walls. When mature, parenchyma cells generally have a large central vacuole. Parenchyma cells perform most of the metabolic functions of the plant, synthesizing and storing various organic products. For example, photosynthesis occurs within the chloroplasts of parenchyma cells in the leaf. Some parenchyma cells in stems and roots have colorless plastids that store starch. The fleshy tissue of many fruits is composed mainly of parenchyma cells. Most parenchyma cells retain the ability to divide and differentiate into other types of plant cells under particular conditions—during wound repair, for example. It is even possible to grow an entire plant from a single parenchyma cell.
Grouped in strands, collenchyma cells help support young parts of the plant shoot. Collenchyma cells are generally elongated cells that have thicker primary cell walls than parenchyma cells, though the walls are unevenly thickened. Young stems and petioles often have strands of collenchyma cells just below their epidermis. Collenchyma cells provide flexible support without restraining growth. At maturity, these cells are living and flexible, elongating with the stems and leaves they support.
Sclerenchyma cell
A rigid, supportive plant cell type usually lacking a protoplast and possessing thick secondary walls strengthened by lignin at maturity.
Lignin
A relatively indigestible strengthening polymer that accounts for more than a quarter of the dry mass of wood.
Protoplast
Living part of the cell
Two types of schlerenchyma cells
Sclereids
Fibers
Sclereid
A short, irregular sclerenchyma cell in nutshells and seed coats. Sclereids are scattered throughout the parenchyma of some plants.
Fiber
A lignified cell type that reinforces the xylem of angiosperms and functions in mechanical support; a slender, tapered sclerenchyma cell that usually occurs in bundles.
Parenchyma cell
A relatively unspecialized plant cell type that carries out most of the metabolism, synthesizes and stores organic products, and develops into a more differentiated cell type.
