300 likes | 458 Views
BELL WORK :. Copy the entire question. Underline key words in the question. Science Fact of the Day: An ostrich's eye is bigger than its brain.
E N D
BELL WORK: • Copy the entire question. • Underline key words in the question.
Science Fact of the Day:An ostrich's eye is bigger than its brain.
CO: I will describe and analyze the transport system in plants.LO: I will write notes. I will draw and discuss how homeostasis is maintained in a plant.
Homeostasis refers to an organism’s ability to maintain a stable internal condition Think-Pair-Share What are some examples of things your body regulates? **Regulate=control; maintain homeostasis***
Homeostasis is maintained through feedback loops • Negative feedback loop = when something goes wrong the opposite thing is added to return to the original condition • Ex. Shivering • Positive feedback loop = when something goes wrong more of the same thing is added to return to the original condition • Ex. Blood clots when you cut your finger
Today we’re going to look at how plants maintain homeostasis.
Vascular tissue: specialized tissue used to move water and nutrients throughout a plant.
Roots • Hold plant in position • Absorb water and minerals from the soil
Root hairs: Fragile parts of cells that grow from the main root Massively increase the surface area for absorption
Stems: - are supporting structures that connect roots and leaves- carry water and nutrients between them through the xylem and phloem
Xylem:carries water upward from the roots to every part of the plant.Phloem: transports food (nutrients) produced by photosynthesis.
Leaves: organs that perform photosynthesis and contain one or more bundles of vascular tissue
Cuticle: a thick waxy layer on the top of the leaf that protects the leaf against water loss and injury.
Conserves water Structures of the Leaf Photosynthesis Transports water and sugar to stem and roots
Gas exchange • Leaves are designed to allow carbondioxide to get to the main chlorophyll layer at the top of the leaf • They have small holes called stomata on the under surface • Each hole is open & closed by 2 guard cells
Stomata: openings in the underside of the leaf that allow carbon dioxide and oxygen to diffuse (move) into and out of the leaf.Guard cells:specialized cells in the epidermis that control the opening and closing of stomata.
Stoma is a small hole Its size is controlled by 2 guard cells open closed
Stoma function is for gas exchange in the leaf oxygen Guard cell Provided plant is photosynthesising Carbon dioxide
Stomata open and close at different times of the day When it is light the plant needs CO2 for photosynthesis so the stoma open At night (darkness) they close
Osmoticpressurekeeps a plant’s leaves and stems rigid.Wilting results from the lack of water—and therefore of the pressure in a plant’s cells.
Mix-Freeze-Group Guard Cell Phloem Transpiration Xylem 2 3 4 5 • I am the vascular tissue that transports nutrients through the plant. • I am the structure around the stomata that allows gases to enter and exit the leaf. • I am the process during which water is lost through the leaves. • I am the vascular tissue that transports water throughout the plant.
Homeostasis Scenario:What would happen to the plant if there was a drought?
Homeostasis Scenario:What would happen to the plant if there was a flood?
Homeostasis Scenario:What would happen to the plant if there was extra carbon dioxide in the air due to some crazy person singing to it everyday?
Homeostasis Scenario:What would happen to the plant if there was not enough carbon dioxide in the air?
Draw your own feedback loop for nutrient uptake in a plant. Remember, most nutrients are used in photosynthesis to make glucose.
What would the plant do if… • There was a drought? • There was a flood? • There was extra carbon dioxide in the air due to some crazy person singing to it everyday? • There was not enough carbon dioxide in the air?