Chapter Thirteen: Plant Processes
Section One: Photsynthesis
Vocabulary
Photosynthesis- the process by which plants, algae, and some bacteria use sunlight, carbon dioxide, and water to make food
Chlorophyll- a green pigment that captures light energy for photosynthesis
Cellular Respiration- the process by which cells use oxygen to produce energy from food
Stoma- one of the many openings in a leaf or a stem of a plant that enable gas exchange to occur
Transpiration- the process by which plants release water vapor into the air through stoma
Chapter Thirteen, Section One: Summary
What happens during transpiration.
Section one was about how plants photosynthesize. Chloroplasts have another membrane inside them called grana. Grana contain chlorophyll. chlorophyll absorbs more green wavelengths than any other. Chlorophyll capture light energy and use it to make glucose molecules, as this happens oxygen is given off. The equation for photosynthesis is 6CO2 + 6H2O + Energy --> C6H12O6 + 6O2. Plants get energy by breaking down glucose and other molecules, this is called cellular respiration. Plants use oxygen in this process and give off carbon dioxide and water. Carbon dioxide enters through stomata in the plant's leaves. Stomata are open by guard cells. Oxygen leaves through stomata. Transpiration is when water vapor exits a leaf. Plants wilt when they lose more water than absorbed Photosynthetic organisms use photosynthesis. Some animals eat photosynthetic organisms indirectly.
Section Two: Reproduction of Flowering Plants
Vocabulary
Dormant- describes the inactive state of a seed or other plant part when conditions are unfavorable to growth
Chapter Thirteen, Section Two: Summary
A diagram of fertilization.
Section two was about how plants reproduce. Pollen lands on a stigma and a tube grows from each grain of pollen. The tube grows into an ovule. The sperm fuses to the egg inside the ovule. When ovules are fertilized the they develop into a seed. The ovary becomes a fruit. Fruits help spread seeds. Animals also help spread seeds when they eat the fruit. A seed can become dormant when conditions aren't right for sprouting Flowering plants can also reproduce asexually by plantlets, tubers, and runners. Plantlets are tiny leaves grow on the edge of leaves and fall off on their own. Tubers are underground stems. Runners are above ground stems.
Section Three: Plant Responses to the Environment
Vocabulary
Tropism- the growth of all or part of an organism in response to an external stimulus, such as light
Chapter Thirteen, Section Three: Summary
The plant's shoot is growing away from the center of the earth.
Section three was about plants reaction to the environment. Plants growing toward light is a positive tropism. A change in the direction plants grow because of light is phototropism. Cells grow longer on one side causing the shoot to bend. Plants can also be affected by gravity is called gravitopism. When a plant is tipped on its side the shoot starts growing away from the center of earth and the roots grow towards the center of earth. The shoots growing away is a negative tropism. The roots growing toward the center of earth is a positive tropism. Plants are affected by seasons changing. Plants also respond to changes in daylight. Trees that keep their leaves all year are evergreens. Trees that loose their leaves the same time every year are deciduous trees. When fall approaches, the green pigment leaves and the yellow and orange pigment become more visible. The yellow and orange pigment have been there all along, they just weren't visible.