Plant Physiology, Growth and Development Flashcards
absorb water and minerals (nutrients) from the soil
Roots
To grow, flower, and produce seeds, plants need a variety of _________ in addition to carbon dioxide and water
Inorganic Nutrients
Most important nutrients that plants need
Nitrogen, Phosphorus, Potassium, Magnesium, Calcium
______ comes from the soil, while _______ comes from the air
Water and Minerals, Carbon dioxide
What are the positively charged minerals that adhere by electrical attraction to the negatively charged surfaces of clay particles
Potassium (K+), Calcium (Ca2+), Magnesium (Mg2+)
Minerals that are negatively charged that are less tightly bound to soil particles and tend to leach away more quickly
Nitrate (NO3-), Phosphate (H2PO-4), Sulfate (SO4^-2)
are made available to the plant when hydrogen ions (H+ ) in the soil displace the mineral ions from the clay particles
Positively charged mineral ions
A process that is stimulated by the roots, which secrete H+ and compounds that form acids in the soil solution.
Cation exchange
What do cell membrane of root epidermal cells contain
Active Transport Protein (ATP)
Movement of water to the side with the greater concentration of
solute (a passive transport of water)
Osmosis
move water and minerals from the root epidermis into the cortex
Osmosis and active transport
The water and dissolved minerals pass the inner boundary of the cortex and enter the _____
Endodermis
Cells in the endodermis are made waterproof by the
Casparian strip
Each endodermal cell is surrounded on four sides by a
waterproof strip called the
Casparian strip
What kind of transportation does Casparian strip controls
Apoplastic Transport
the cytoplasmic continuum
Symplast
the continuum of cell walls plus extracellular spaces
Apoplast
pushes water through the vascular system of the entire plant
Root pressure
Water and minerals ascend from roots to shoots through the
Xylem
Water is pulled upward by
_________ in the xylem
negative pressure
Water is pulled up through the xylem
Transpiration, Adhesion, Cohesion, and Tension
generated by transpiration is largely responsible for the upward movement of water in xylem
negative pressure
According to this theory: Due to transpiration, water is lost in the form of vapor from the leaves
Transpiration Pull Theory
powers photosynthesis and these sugars are transported via the phloem (translocation)
Sunlight
Materials are translocated in the phloem from sources (usually mature leaves) to sinks (roots, immature leaves)
Phloem transport
also called mass-flow or bulk flow
Pressure flow model
Translocated solutes are mainly
Carbohydrates
It is the most common translocated sugar
Sucrose
Phloem also contains
Amino acids, proteins, inorganic ions, and plant hormones
Sugars and other organic materials are conducted throughout the plant in the phloem by means of
Sieve tube elements
is driven by a gradient of pressure.
Flow
It is required to establish the pressure gradient, but energy is not required by cells of the pathway itself.
Energy
Often occurs at night, is caused by the continued, active accumulation of ions in the roots at times when transpiration from the leaves is very low or absent
Root pressure
The exudation of water droplets (xylem sap) on tips of grass blades or the leaf margins of some small, herbaceous eudicots
Guttation
does not take place through the stomata, but instead occurs through special groups of cells located near the ends of small veins
Guttation
Are connected to the plant vascular system by a vascular bundle. It probably evolved from modified stomata
Hydathodes
The evaporation of water vapor from plant surfaces; especially in leaves (through the stomata), also in stems, flowers, and roots.
Transpiration
When is stomata usually closed
when there is too little water available, temperature is low, or there is little light.
Stomatal Control is controlled by
Guard cells