Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
The flower is the reproductive organ of many plants. It contains male parts called the stamen (comprising the anther and filament) and female parts called the carpel or pistil (comprising the stigma, style, and ovary).
Pollination is the transfer of pollen grains from the anther of a stamen to the receptive stigma of a carpel. This can occur via wind, insects, birds, or water.
Fertilization occurs when the male gamete (pollen) travels down a pollen tube to fuse with the female gamete (ovule) inside the ovary. This produces a zygote: .
Insect-pollinated flowers typically have large, brightly colored petals and produce nectar to attract pollinators, while wind-pollinated flowers have small, dull petals and exposed anthers to catch the wind.
Seed dispersal is the movement of seeds away from the parent plant to reduce competition for resources like light, , and minerals. Methods include wind (e.g., dandelions), water (e.g., coconuts), animals (e.g., berries), and explosion (e.g., pea pods).
Germination is the process where a seed begins to grow into a plant. It requires specific conditions: (often remembered by the acronym WOW).
📐Formulae
💡Examples
Problem 1:
A flower has very long filaments that hang outside the petals and produces massive amounts of tiny, light pollen grains. Identify the most likely method of pollination.
Solution:
Wind Pollination
Explanation:
Wind-pollinated flowers have evolved to have long filaments so that the wind can easily blow the pollen away. The pollen is light and produced in large quantities to increase the statistical chance of landing on a stigma of another flower.
Problem 2:
Explain the role of the ovary after fertilization has taken place.
Solution:
The ovary develops into a fruit.
Explanation:
Once fertilization is complete (fusion of gametes), the ovules turn into seeds, and the surrounding ovary tissue swells and matures to become the fruit, which helps in the dispersal of the seeds.
Problem 3:
If a plant is kept in a vacuum (an environment with no air/gases) but provided with and sunlight, will the seeds germinate? Explain using scientific requirements.
Solution:
No, the seeds will not germinate.
Explanation:
Germination requires three specific conditions: , , and . In a vacuum, there is no (Oxygen), which is required for aerobic respiration to provide the energy needed for the embryo to grow.