Biologia

Lab practice 1#

INTRODUCTION:

What are guard cells?

Guard cell’s job is to is to open and close the stomata.

Stomata are the pores found on the leaves of plants. Their function is toallow carbon dioxide to enter the leaf (for photosynthesis) and oxygen (made by photosynthesis) to leave the leaf.

Usually stomata open during the day and close at night. This is to save water, sincewater vapor can escape as long as the stomata are open.

The guard cells control the size of the stomatal pore by changing their shape. When they are curved, a gap opens up between them. When theystraighten (lose their curved shape) the gap is closed.

The change in shape is caused by water either entering the guard cells (to open the stomata) or leaving the guard cells (to close the stomata).OBJECTIVES:

To identify different kinds of plant tissue, compression of photosynthesis and manipulation of stoma and guard cells.

RESULTS:

With many different types of fresh water wedived into size, the bigger 2 were separated one of them was putted into salty water and the other one was putted on a glass with a candle.

The objective of having them into different situations willhelp us to see a bigger difference at the microscope.

The first leave (the wet one) under the microscope looked greener, had very small “roads” around it in my team’s opinion we thought that in thisone the guard cells and the stomata had accomplish their jobs to remain hydrated the leave, and that is why the “roads” are small and the leave Is green.

In the other hand the other leave (the onewith the candle) when we saw it under the microscope we realize that it was very different, it was brown and its “roads” were really big, after analyzing it we get the answer, because it was near thefire all the oxygen was gone that means that no oxygen no water and the “roads” were big because the guard cells and the stomata were looking for water.






CONCLUTIONS:

We do find...