Simone Flashcards
Plant Basic Exam 2
What is a gymnosperm?
“naked seed plants”
produces sees but not flowers or fruit
seeds are exposed on the surface of modified flowers
What is an angiosperm?
Flowering plants
produces flowers, produces seeds enclosed by fruit
What are the four groups of gymnosperms?
Phylum Ginkgophyta
Phylum Cycadophyta
Phylum Gnetophyta
Phylum Coniferphyta
What is Phylum ginkgophyta?
gymnosperm with no fruits, fleshy seed coat
dioecious (male and female parts)
What is Phylum Cycads?
dioecious (male and female parts)
have specialized roots with symbiotic cyanobacteria
What is cyanobacteria?
type of microorganisms that are similar to bacteria and is capable of photosynthesis, provides the plant with nitrogen
What is Gnetophyta?
Includes the genus Ephedra, young stems are photosynthethic and acquires nearly all water from dew and condensation on two leaves
What are conifers?
Most diverse and numerous groups of gymnosperms, dominate high latitude and adapts to dry conditions
What are microspores?
develop into male gametophyte?
What are megaspores?
develop into female gametophyte
Where do you find megasporiums?
In seed plants, they are found in the ovule
What is diffusion?
Movement from an area of high concentration to an area with a lower concentration. Driven by concentration gradient.
Osmosis
diffusion of water through a semipermeable membrane from an area of high concentration to an area of lower concentration
osmotic potential
the measure of the potential of water to move from one cell to another as influenced by solute concentration
Holophyte
plants able to grow in salty habitats
Guttation
the secretion of droplets of water from the pores of plants, xylem
Brownian Movement
the random motion of particles suspended in a fluid resulting from their collision with the fast-moving molecules in the fluid.
What affects the rate of diffusion?
presssure, temperature, and the medium in which everything is taking place
Solvents
liquids in which substances dissolves
Semipermeable membranes
when different substances diffuses at different rates
When does osmosis stop?
when the concentration of water on both sides is equal
what happens to water gained by osmosis?
Keeps the plant turgid
Turgor pressure
the force within the cell that pushes the plasma membrane against the cell wall.
Water potential
is the combined osmotic potential and pressure potential of plant cells
Plasmolysis
loss of water through osmosis, accompanied by shrinkage of protoplasm away from the cell wall.
Imbibition
Swelling of tissues to at least twice its size, whether dead or alive, initial step to germination of seeds
Active transport
The absorbing and retaining solutes against diffusion (electrical) gradient by using energy. (involves a proton pump)
Osmotic Pressure
pressure used to prevent osmosis
What is the primary way water enters plants from the environment?
By Osmosis.
- Water flows from Soil >Cell wall & intercellular spaces in roots
- Crosses through permeable membrane>cytoplasm of endodermis> xylem
- flows through xylem>leaves>diffuses out of stomata
Transpiration
Water vapor loss from internal leaf atmosphere. 90% of water entering a plant is transpired.
What is the water needed for in a plant?
Cell activities, Cell turgor, Evaporation for cooling (stomata closes when more water is loss then taken in)
Stomata
A minute pore or opening in the epidermis of leaves, herbaceous stems, and it is flanked by two guard cells that regulate its opening and closing thus regulating gas exchange and transpiration.
What is Cohesion-Tension Theory?
Transpiration generates tension to pull water columns in vessels and tracheids through plants from roots to leaves.
What happens when water evaporates from mesophyll cells?
They develop a lower water potential than adjacent cells and move to those adjacent cell with a higher water potential.
What regulates transpiration?
Stomatal Apparatus
What is Pressure-Flow Hypothesis?
- Water enters by osmosis
- Organic solute flow from source**
- To Sinks**
- Where Food is utilized and water exits.
Macronutrients
Nutrients used by plants in greater amounts
Micronutrients
Nutrients used by plants in smaller amounts
What do molecules move along during diffusion?
Against a Concentration Gradient
Water Potential
osmotic potential + pressure potential
water moves from cell with higher water potential to cell with lower water potential
proton pump
enzyme complex in plasma membrane energized by ATP molecules
phloem loading
sugar enters by active transport into sieve tubes
water potential of sieve tubes [blank] and water enters by [blank]
decreases, osmosis
turgor pressure develops and drives fluid through [blank] toward [blank]
sieve tubes, sinks
The water and the sugar solution flows along the pressure gradient towards a
Sink
Sugar molecules are moved by active transport from the phloem to storage [blank] cells in the root.
parenchyma
which tissue is resposible for transports in plants?
Vascular tissue systems
The transport cells in [blank] are dead at maturity
Xylem
Trichomes
are hairlike projections of the epidermis that may be useful in defense and in reducing evaporation.
Lenticels
are found in the periderm of woody stems
Endodermis
Regulation of movement of materials into the vascular cylinder of the root is controlled primarily by the:
Secondary Xylem
where the growth rings of trees found in temperate zones are visible
Leaf abscission can be triggered by
drought, changing weather and stress
