Term | Definition |
Stomata | openings in leaf through which gases like CO2 and O2 pass |
Guard Cells | surround the stomata and control their opening and closing based on water level, light conditions, and glucose levels |
Palisade | upper layer of cells in a leaf, responsible for most of the photosynthesis in the leaf |
Chloroplasts | organelles in plant cells responsible for photosynthesis |
Chlorophyll | green pigment in plants and some protists and bacteria responsible for absorbing light energy |
Photosynthesis | the conversion of light energy into chemical energy (glucose) through the use of carbon dioxide and water |
Light-dependent Reactions | take place in the presence of light; primarily the splitting of water into hydrogen, which is saved by the plant cell, and oxygen, which is released as oxygen gas |
Light-independent Reactions | take place with or without light energy; carbon dioxide is converted into glucose with the help of enzymes and addition of hydrogen from light-dependent phase |
Cellular Respiration | series of chemical reactions that convert chemical energy (stored in glucose) into energy form useful to cells. |
Internal Stimulus | a factor from the inside which causes some change in the life processes of a creature |
External Stimulus | a factor from the outside which causes some change in the life processes of a creature |
Tropism | growth in response to a stimulus |
Photo | refers to light |
Thigmo | refers to touch |
Baro | refers to pressure |
Gravi | refers to gravity |
Chemi | refers to chemicals |
Hormone | a chemical released by a creature which controls a life process |
Ethylene | * ripens fruit
* slows growth of terminal buds
* controls dropping of leaves and fruit |
Abscisic Acid | * slows life processes of plant
* prevents bud growth during winter months
* closes stomata on hot summer days |
Gibberellins | * promotes seed germination
* promotes flowering
* speed up life processes
* promotes elongation of plant cells |
Ctyokinins | * promote cell division
* promote lateral growth (new branches) |
Auxin | * causes cell elongation selectively (phototropism)
* collects in the shaded and/or bottom parts of stems/roots
* suppresses lateral growth (branches) |
Photoperiodism | a plant's response to the amount of daylight it receives |
Long Day Plants | produce blossoms when there is less than 12 hours of darkness (during the summer months) {Iris, cabbage, lettuce, carrots} |
Short Day Plants | produce blossoms when there is more than 12 hours of darkness (during spring or autumn months) {sunflowers, cucumbers, sweet potato, tulips} |
Day Neutral Plants | produce blossoms independent of how many hours of daylight they receive {dandelion, rhubarb, strawberry, kale} |