Plant Structure & Tissues
What are the three main plant organs?
Roots, stems, and leaves
How many cotyledons does a monocot have?
one
What cells control the opening and closing of stomata?
Guard cells
What type of transport moves fluids long distances in plants?
Bulk Flow
What structure of the flower produces pollen?
Anther
What tissue transports water and minerals upward through the plant?
Xylem
Which group typically has vascular bundles arranged in a ring?
Eudicots
What ion is actively transported into guard cells to open stomata?
Potassium (K⁺)
What process causes water to evaporate from leaves?
Transpiration
What is double fertilization?
One sperm fertilizes the egg; the other fertilizes the central cell to form endosperm
What is the difference between a taproot system and a fibrous root system?
Taproot has a main primary root; fibrous roots lack a main root.
What type of leaf venation is usually found in monocots?
Parallel venation
What hormone causes stomata to close during drought conditions?
Abscisic acid (ABA)
According to the cohesion–tension hypothesis, what pulls water upward in xylem?
Transpirational pull
What is the ploidy of the endosperm in angiosperms?
Triploid (3n)
Name the two types of cells that make up phloem and state whether they are alive or dead at maturity.
Sieve-tube elements and companion cells; both alive
Describe the arrangement of xylem and phloem in a eudicot root.
Star-shaped xylem with phloem between the arms
When guard cells are turgid, are stomata open or closed?
Open
Why can xylem cells withstand negative pressure without collapsing?
Thick secondary cell walls
What process converts a microsporocyte into microspores?
Meiosis
What is apical dominance, and what structure is responsible for it?
Suppression of axillary bud growth by the apical bud
Which group typically produces pollen grains with three openings?
Eudicots
Name two environmental factors that can trigger stomatal closure.
Drought, high temperature, or wind
How does phloem transport differ from xylem transport in terms of pressure?
Phloem uses positive pressure; xylem uses negative pressure
What are the three components of a seed?
Embryo, endosperm, seed coat