AP BIOLOGY Investigation 11: Transpiration
2012 AP BIO LAB MANUAL INVESTIGATION 11 TRANSPIRATION ***LOOK AT 2001 LAB MANUAL, LAB 9***
Terms in this set (35)
AP BIOLOGY INVESTIGATION 11: TRANSPIRATION
Cells and organisms must exchange matter with the environment to:
The ability of cells to exchange with the environment depends on:
the availibility of these resources
All organisms must maintain properly
Plants absorb and transport ____, ____ and ___ from the soil via ___, ___ and ____
1) water, nutrients, ions
2) osmosis, diffusion, active transport
Where the water and dissolved nutrients enter the plant
Water and nutrients go where from the root xylem and how?
They are transported upward to the STEMS and LEAVES as a part of the process of transpiration
Transpiration results in
water loss due to evaporation of water from the leaf surface
Too much water loss can be detrimental to plants. how?
They can wilt and die
The transport of water upward from roots to shoots in the xylem is governed by
differences in water (osmotic) potential
Water (or osmotic) potential
Where water molecules move from an area of high water potential to an area of low water potential
Area of high water potential characteristics
higher free energy
area of low water potential
lower free energy
The movement of water through a plant is facillitated by:
osmosis, root pressure, and the physical and chemical properties of water
lower osmotic potential in the leaf
a mechanism that describes the forces that move water and dissolved nutrients up the xylem
During transpiration, water escapes through
holes in the leaves called stomata
small pores in the leaves which open up to release oxygen and take in carbon dioxide. Water is often times released in this process.
Part one of the lab involves calculating:
leaf surface area
Leaf Surface area is then used to find
average stomata per square millimeter
LEARNING OBJECTIVE 1:
To investigate the relationship among leaf surface area, number of stomata, and the rate of transpiration
LEARNING OBJECTIVE 2:
To design and conduct an experiment to explore other factors, including different environmental variables, on the rate of transpiration
LEARNING OBJECTIVE 3:
To investigate the relationship between the structure of vascular tissues (xylem and phloem) and their functions in transporting water and nutrients in plants
A device that is used to see water loss which we DID NOT use
If a plant cell has a lower water potential that its surrounding environment, make a prediction about the movement of water across the cell membrane.
WILL the cell gain OR loose water?
The higher water potential outside of the cell will cause the water to move into the plant cell to acheive homeostasis -- the cell will GAIN water
In the winter, salt is spread over icy roads. In the spring, after the ice has melted, the grass dies. What causes this to happen?
The salt causes the water to leave the cell to achieve homoestasis (because the solution increases the need for water so that it can be equal) and all of the water eventually leaves the cell.
If you wanted to move a tree, would you move to move it in the winter when it doesnt have any leaves but it is cold or in the summer when it has leaves but it is hot?
You should move it during the summer, because in the winter all of its nutrients are stored in the roots. pulling the tree from the ground in the winter will result in the loss of roots, and the tree will die. In the summer, it has the ability to gain nutrients after replanting.
How to calculate the total surface area of a leaf?
Measure the top and bottom of one leaf
Of a whole plant?
Multiply this number by the number of leaves
What predictions can you make about the number of stomata and rate of transpiration?
More stomata = More transpiration
because carbon dioxide is transferred through the stomata, can you give a reason as to why there were higher amounts of carbon dioxide millions of years ago but lower now?
There were less stomata to regulate it. They take the carbon dioxide and turn it in to oxygen. If there were a lot of oxygen there would have been more stomata.
Relationship between environment and stomata location (table)
Water environment has more stomata above the plant while a dry environment has them on the bottom.
Width of view at 400x