Plants November 9 & 10

Standards Covered Analyze dormancy Describe pollination and seed dispersal

Dormancy Defined: When a plant undergoes a period of inactivity during unsuitable growing conditions. When a seed is prevented from germinating INACTIVE

Dormancy Explained Some seeds do not undergo germination until they have experienced freezing temperatures (this is an example of dormancy). Some seeds undergo a fire before they will germinate because the fire triggers the end of their dormancy.

Dormancy Habits Deciduous trees prepare for winter dormancy by cutting off nutrients and water from their leaves. Some trees’ leaves change color during fall because they have been separated from the rest of the tree and are no longer receiving the nutrients needed to make chlorophyll.

Dormancy in heat Droughts will trigger dormancy in plants Example: Palo Verde

Dormancy Danger A brief warm spell that occurs in the middle of winter is dangerous. If the plant ends its winter dormancy when it detects a warm temperature it will not be able to survive. Very similar to arising from hibernation too early.

Critical Thinking What would happen if dormancy did not happen in seeds? Compare and contrast dormancy and hibernation.

Pollination Defined: When pollen from the male part of a flower enters the female part of a flower, resulting in the production of seeds.

Hummingbirds Hummingbirds help plants reproduce by moving pollen from the male flower parts to the female parts.

Insects Insects help plants reproduce by transferring pollen.

Activity Pollination exercise! How would we see evolutionary traits develop in flowers? What if you were the only one with Cheetos in the room? Could you pollinate?

Germination Defined: The process by which a plant grows from a seed or the growth of a sporeling from a spore.

Seed Dispersal Defined: The movement or transport of seeds away from the parent plant.

Dispersal by Animals One way to spread seeds is by animals digesting the seeds and “disposing” of them. Example: Blackberry seeds

Dispersal by Wind Many seeds are located inside a capsule within flowers. Once the petals fall off, the capsule becomes exposed and holes form in the capsule. They are then taken away by the wind. Example: Poppy seeds

Dispersal by Water Waterproof Floatation Example: Water lilies

Problem Solving List as many seeds as you can that could be carried by… Wind Water Animals Pick one of the seeds you listed. Suppose that something happened so that it could not be dispersed by those means anymore. Fix the problem!