BIO 242 Chapter 35 and 36 Flashcards
How do guard cells act around the stomata?
When turgid they swell and open. When flaccid they relax and close.
Where does secondary (lateral) growth come from?
Vascular cambium. Production of secondary xylem on inside and secondary phloem on outside of the vascular cambium ring cells.
What are the five basic plant hormones? (ACAGE)
Auxins, Cytokinins, Abscisic acid, Gibberellins, Ethylene
What is included in bark?
All tissues external to the vascular cambium, including secondary phloem, cork cambium, and cork.
What are auxins?
Plant hormones produced by shoot meristems and young leaves that stimulate stem and cell elongation and cause phototropism (bending toward or away from light).
What are cytokinins?
Plant hormones produced by growing tissues in fruits and roots and cause larger cells to divide. They slow plant aging and leaf separation and help plants stay green longer.
What is abscisic acid?
Plant hormones that inhibit growth of parts of plants and stomata opening to survive short-term periods of drought.
What are gibberellins?
Plant hormones that promote stem elongation and seed germination by stimulating digestive enzymes in the endosperm. (sprayed on seedless grapes)
What is ethylene?
Plant hormone that promotes the ripening of fruits and causes leaves of deciduous trees to drop in the fall. Placing fruits in high levels of carbon dioxide prevents ethylene production, which prevents ripening.
How does wood form?
As secondary growth continues over the years, layer upon layer of secondary xylem accumulates.
What is lignin?
Coating of xylem that gives wood its hardness and protection.
What are the two zones of secondary xylem?
Heartwood (doesn’t conduct water but is central column that supports tree) and Sapwood (upward transport of water and minerals by xylem sap)
What are the 3 basic kinds of plant organs?
Roots (underground) and stems and leaves (shoots above ground)
What’s the importance of roots and shoots (stems/leaves) systems?
Roots are underground and is where plants get water and nutrients. Shoots are above ground and is where the plant gets CO2 and light energy.
What is apical dominance?
It causes the plant to grow taller instead of wider to increase the plant’s exposure to sunlight.
How are plants and animals different?
1) Plants are usually modular - made of many copies of a small number of units (leaves, etc.)
2) Plants can reproduce asexually
3) Plants grow throughout their life
What are key differences between monocots and eudicots?
1) Monocots have fibrous roots; eudicots have a taproot system
2) Monocots have one cotyledon; Eudicots have two (first leaves that come out of the embryo)
3) Monocots have parallel veins on leaves; Eudicots have netlike veins
4) Monocots have vascular bundles on stems are scattered; Eudicots bundles are in a ring
5) Monocots have one pollen grain opening; Eudicots have three
6) Monocots petal # divisible by 3; Eudicot petal # divisible by 4 or 5
Root hairs are extensions of what?
Individual epidermal cells
What are stolons?
Runners or above ground horizontal stems
What are rhizomes?
Horizontal underground stems
What are tubers?
The ends of rhizomes
What are adventitious roots and pneumatophores?
Specialized above ground roots like corn and swamp grass.
