CATEGORY 1 — Tropisms & Plant Behavior
This type of tropism makes plant stems grow upward, opposite the pull of gravity.
Answer: What is negative gravitropism?
These plants bloom when nights last longer than their critical night length.
Answer: What are short-day plants?
This hormone helps fruit release aroma, soften, and change color.
Answer: What is ethylene?
These colorful structures help attract pollinators like bees and birds.
Answer: What are petals?
Pinecones belong to this group of seed-producing plants.
Answer: What are gymnosperms?
This tropism causes roots to grow toward moisture in the soil.
Answer: What is hydrotropism?
These plants can flower regardless of day or night length.
Answer: What are day-neutral plants?
This hormone keeps seeds from sprouting too early.
Answer: What is abscisic acid?
This is the sticky surface where pollen lands.
Answer: What is the stigma?
This group includes flowering plants that produce fruits.
Answer: What are angiosperms?
A plant bending toward a window is responding to this stimulus.
Answer: What is light (or phototropism)?
In mosses and ferns, this life-cycle stage produces gametes.
Answer: What is the gametophyte stage?
This hormone promotes cell division and is often sprayed to delay aging in cut flowers.
Answer: What is cytokinin?
This part produces pollen.
Answer: What is the anther?
This structure in ferns produces spores.
Answer: What is the sporophyte?
If a plant grows away from a source of touch, such as a vine recoiling, what type of tropism is it showing?
Answer: What is negative thigmotropism?
This process begins when a seed takes in water and starts to grow.
Answer: What is germination?
This hormone causes stems to lengthen and helps plants bend toward light.
Answer: What is auxin?
This is the entire female part of the flower.
Answer: What is the carpel (or pistil)?
Plants like mosses and liverworts lack vascular tissue and depend heavily on water.
Answer: What are nonvascular plants?
When light comes from only one side, this plant hormone is responsible for bending the plant by collecting on the shaded side.
Answer: What is auxin?
Seedless plants need this environmental factor for reproduction because their sperm must swim.
Answer: What is water?
This hormone helps trees prepare for winter by sealing off vessels before leaves fall.
Answer: What is abscisic acid (or “abscission process”)?
This tube grows down through the style so sperm can reach the ovule.
Answer: What is the pollen tube?
These specialized roots anchor mosses to surfaces but do not transport water like true roots.
Answer: What are rhizoids?