Studied by 4 people
Alternation of Generations
a pattern of reproduction occurring in the life cycles of lower plants. the generations are alternately sexual and asexual (as in ferns)
Apical Meristem
a region of cells capable of division and growth in the root and shoot tips in plants.
What characteristics do charophytes share with land plants?
both contain carotenoids and chlorophyll a and b
both store carbohydrates as starch.
What are examples of derived traits in plants?
alternation of generations
multicellular dependent embryos
walled spores produced in sporangia
multicellular gametangia
apical meristems
What are the four extant phyla of gymnosperms?
Coniferophyta, Cycadophyta, Gnetophyta, Ginkgophyta
Characteristics of Coniferophyta
Perennial woody plants with secondary growth
Cone bearingC
Characteristics of Cycadophyta
Resemble palms but have cones
Large compound leaves
Slow growing, found in tropical regions
Sago palm, cycas, zamia
Characteristics of Gnetophyta
Very diverse (though small) phylum
Only gymnosperms with vessels in their xylem
Vessel elements resemble angiosperms, but DNA analysis suggests relatedness to conifers
Ephedra viridis - Mormon tea, gnetum gnemon, welwitschia mirabilis
Characteristics of Ginkgophyta
Ginkgo biloba - only living species
Male and female reproductive structures form on different trees
High resistance to pollution
Characteristics of Angiosperms
Have flowers or fruits to protect seeds
Characteristics of Gymnosperms
Have no flowers or fruits, “naked seeds”
Came before angiosperms
Characteristics of Monocots
One cotyledon (an embryonic leaf in seed-bearing plants, the first leave(s) to appear from a germinating seed)
Parallel veins in leaves
Scattered stem in vascular tissue
Network of fibrous roots
Monosulcate pollen (a pollen grain with one groove or furrow)
Flower parts come in threes or multiples of three
Monocots do not produce true wood (hard structural tissue).
Instead produce grasses, palms (herbaceous)
Characteristics of Eudicots
Two cotyledon
Network veins in leaves
Ring pattern stem vascular tissue
Tap root with many lateral roots
Trisculate pollen
Four, five, multiple of four or five and whorls flower parts
Produce true wood
Secondary growth
Remember all plants have primary growth at the apical meristems (roots and shoots)
Secondary growth deals with expanding girth and creating wood. Wood is proliferating xylem
Moss Life Cycle
Fern Life Cycle
Microphyll
a leaf (as of a club moss) with single unbranched veins and no demonstrable gap around the leaf trace.
Importance of symbiotic fungi
plants would not have been successful in the move onto land without them
Which type of plant has the haploid gametophyte as the most important form?
non-vascular plants
Difference between sporophytes and gametophytes
Sporophytes are 2n (diploid) and gametophytes are n (haploid)
megasporangia
produce megaspores which produce female gametophytes
microsporangia
produce microspores which produce male gametophytes
Example of plant adaptions to life on land
seeds and pollen grains
dispersal of sperm no longer dependent on water
Female parts of the plant
collectively called the pistil
Stigma
The part of the pistil where pollen germinates
Style
a long, slender stalk that connects the stigma and the ovary. The stigma is at the top of the style and is a sticky platform where pollen is deposited
Ovary
The enlarged basal portion of the pistil where ovules are produced.
Ovule
the organ that forms the seeds of flowering plants
Male parts of the plant
Stamen
consists of a long slender stalk, the filament, with a two-lobed anther at the tip
Anther
the part of a stamen that produces and contains pollen.
Filament
a stalk-like structure that attaches to the base of the flower and supports the anther
Characteristics of fleshy fruits
the pericarp and accessory parts develop into succulent tissues, as in eggplants, oranges, and strawberries
Characteristics of dry fruits
the entire pericarp becomes dry at maturity, as in grains, nuts, rice, wheat
Complete flower
one that contains all the reproductive (stamens and pistil) and non-reproductive (petals and sepals) parts
staminate flowers (incomplete)
also known as androecious flowers
unisex flowers that bear stamens only and produce pollen grains only
lack carpels
carpellate flowers (incomplete)
also known as gynoecious flowers
unisex flowers that bear carpels only and produce egg cells only
lack stamens
shoot system
Vegetative (non-reproductive) parts of the plant, such as the leaves and the stems
Reproductive parts of the plant, which include flowers and fruits.
root system
Supports the plants and absorbs water and minerals.
Usually underground
Lateral meristems
cells found at the margins of stems and roots. They are an essential component in the process of the stems and roots expanding in width and diameter
What are the parts of a stem?
Nodes, internodes, axillary buds, apical bud
Nodes
points of attachment for leaves, aerial roots, and flowers
Internodes
regions between two nodes
Axillary bud
usually found in the axil—the area between the base of a leaf and the stem—where it can give rise to a branch or a flower
Apical bud
The apex (tip) of the shoot contains the apical meristem
Petiole
stalk that extends from the stem to the base of the leaf is the petiole
Parenchyma cells
the most common plant cells
have the potential to become other cell types
have all the organelles and thin primary cell walls
Collenchyma cells
tissue strengthened by the thickening of cell walls, as in young shoots
elongated like column with thick walls
Sclerenchyma cells
provide support to the cells
Dead at maturity
Lots of lignin
Made of fibers and sclereids
Dermal tissues
Mostly epidermis
Woody plants have bark
Leaves have guard cells as part of stomata and trichomes
Epidermis
the epidermis on above ground organs (leaves and stems) is involved with gas exchange
the epidermis on below ground organs (roots) is involved with water and ion uptake
Vascular tissues
transport water, minerals, and sugars to different parts of the plant
xylem
carries water and ions from the roots to stems and leaves
phloem
carries dissolved sugars from leaves to other parts of the plant
Tracheids
a type of water-conducting cell in the xylem which lacks perforations in the cell wall
Vessel elements
An elongated, water-conducting cell in xylem, one of the two kinds of tracheary elements
Sieve-tube cells (also called sieve-tube elements)
arranged end to end to make up a long sieve tube, which transports organic substances such as sugars and amino acids.
Sugars flow from one sieve-tube cell to the next through perforated sieve plates, which are found at the end junctions between two cells.
Companion cells
found alongside the sieve-tube cells, providing them with metabolic support.
The companion cells contain more ribosomes and mitochondria than the sieve-tube cells, which lack some cellular organelles.
Primary growth
arises from apical meristems
Secondary growth
stem increases in thickness and due to lateral meristems
Ground tissues
responsible for metabolism, storage, and support activities
includes leaves, stems, and roots
leaf (called mesophyll)
uses the energy in sunlight to synthesize sugars in a process known as photosynthesis
stem (called pith and cortex)
develops support cells to hold the young plant upright
root (also called cortex)
often stores energy- rich carbohydrates
What are rhizomes, bulbs, corms, stolons, and tubers?
modified stems
What is wood?
Wood is secondary xylem
Tap root system
A taproot is a large, central, and dominant root from which other roots sprout laterally. Typically a taproot is somewhat straight and very thick, is tapering in shape, and grows directly downward
Fibrous or Adventitious root system
A fibrous root system is the opposite of a taproot system. It is usually formed by thin, moderately branching roots growing from the stem.
A fibrous root system is universal in monocotyledonous plants and ferns
Roots have area of maturation, elongation, and cell division
The zone of elongation is where the newly formed cells increase in length, thereby lengthening the root. Beginning at the first root hair is the zone of cell maturation where the root cells begin to differentiate into special cell types. All three zones are in the first centimeter or so of the root tip.
Dicot root
taproot structure, meaning they form a single thick root, with lateral branches, that grows deep into the soil.
Monocot root
has a ring of vascular tissue: note contrasts with randomness in stems
Stele
inner vascular tissue of root
Pericycle
area lateral roots emerge from
Casparian strip
a barrier to the apoplastic flux, forcing ions to pass through the selectively permeable plasma membrane into the cytoplasm, rather than move along the cell wall.
Types of roots
strangling roots and Cypress “knees”
Strangling roots
when tree roots encircle a tree's trunk
Cypress “knees”
formed on the upper surface of these roots by the vascular cambium, the meristematic layer that produces xylem and phloem, the tissues that transport water and nutrients through the plan
Leaf structure (external)
Tip
Lamina
Petiole
Midrib
Veins
phyllotaxy
the arrangement of leaves around the stem.
Leaf forms
Simple: banana leaf
Pinnately compound: feather-like appearance; the leaflets are arranged along the middle vein
Palmately compound: leaflets radiating outwards from the end of the petiole, like fingers off the palm of a hand
Doubly compound: the leaflets are arranged along a secondary vein, which is one of several veins branching off the middle vein.
internal structure of leaf
Spongy parenchyma in mesophyll
Palisade parenchyma in mesophyll
Upper and lower epidermis
Stomata flanked by guard cells
What are needles?
leaves adapted for dry climates
What is solute potential?
Solute potential (ψ s) s the same as the osmotic potential and is related to dissolved materials
What is pressure potential?
Pressure potential (ψ p) is the physical pressure or turgor pressure on a solution
Transpiration
Loss of water from the plant via evaporation at the leaf surface; ideally an unbroken line of water molecules and all passive
Evapotranspiration
the process by which water is transferred from the land to the atmosphere by evaporation from the soil and other surfaces and by transpiration from plants.
Flaccid
Flaccid corresponds to a cell lacking turgidity.
They are not plump and swollen but floppy or loose, and cells have drawn in and pulled away from the cell wall.
It takes place when plant cells are in isotonic solutions.
turgid
Plant cells become "turgid" when they are put in dilute solutions.
Turgid means swollen and hard.
The pressure inside the cell rises, eventually the internal pressure of the cell is so high that no more water can enter the cell.
cohesion
Water is attracted to water
adhesion
Water is attracted to other substances
What part of the plant controls the rate of transpiration?
the stomata
translocation
the movement of materials from one area to another. In plants, plant translocation involves the movement of sugars from sources to sinks.
Photomorphogenesis
development of form and structure in plants which is affected by light, other than that occurring for photosynthesis.
Photoperiodism
the response of an organism to seasonal changes in day length.
Phototropism
the orientation of a plant or other organism in response to light, either toward the source of light ( positive phototropism ) or away from it ( negative phototropism ).
phytochromes
red (R)/far-red (FR) light photoreceptors that play fundamental roles in photoperception of the light environment and the subsequent adaptation of plant growth and development.
Phototropins
plant-specific blue light receptors for phototropism, chloroplast movement, leaf expansion, and stomatal opening
Horizons are layers of soils
O is leaf litter
A is topsoil
B is subsoil
C is the soil base
Horizon O
The O horizon has freshly decomposing organic matter—humus—at its surface, with decomposed vegetation at its base.
Horizon A
The A horizon consists of a mixture of organic material with inorganic products of weathering, and it is therefore the beginning of true mineral soil
Horizon B
The B horizon is an accumulation of mostly fine material that has moved downward, resulting in a dense layer in the soil. In some soils, the B horizon contains nodules or a layer of calcium carbonate.
Note 
Flashcard (71)