16
15
PROJECT #6: Pond Water
You will need:
microscope
a pail or bucket
an empty jar
pipette
clean, blank slides
slide covers
Get a sample of water from a pond in a wooded area. It is best to get a
sample in the late spring or summer. Dip your pail or bucket in the pond to fill
it. Let it stand still for about a half-hour. Then dip your jar to the bottom of the
pail and try to get some of the sludge that has settled to the bottom. Use your
pipette to place a drop on a blank slide and place a slide cover over it. To do
this, stand the slide cover on end next to the drop. Gently let it fall onto the
drop. Push it lightly with a toothpick, but not hard enough to squash any little
animals. If water has squeezed out around the edges, you can touch a tissue
to it to clean it up. Look through your microscope. Start at 100X and work
upward.
What are all of the small things you see? Are some of them alive? You will
see small bits of dirt and vegetation. If you are lucky, you may see small
creatures moving around. Some of these are tiny baby insect larvae. Others
are very tiny animals that live in the water and feed on the vegetation and on
the insect eggs and larvae. Make careful notes and drawings of what you see.
Things I saw in pond water:
PROJECT #7: Friendly Bacteria
You will need:
microscope
clean, blank slides
slide covers
pipette
yogurt (must say “active cultures” on the label)
water
petri dish
Bacteria are very small life forms that you can only see through a microscope.
Some bacteria make us feel sick. Some bacteria are friendly. Do you like
yogurt? Did you know that friendly bacteria turn milk into yogurt?
Put a drop of natural yogurt on a slide. Mix it with a drop of water and put a
slide cover over it. The sample should be spread very thinly. Look through
your microscope. Scan the area carefully at 300X and 600X. Try to look at the
thinnest areas. You should see small round objects. These are the friendly
bacteria.
Place several drops of yogurt in a petri dish or sample vial. Mix it with several
drops of warm water. Do not cover your sample. Place it somewhere relatively
warm and out of reach. Wait for one day. Using your pipette, place a drop or
two of your sample on a slide and cover it with a slide cover. Look for more
bacteria.
You will probably see more bacteria. They were in the air and landed on the
yogurt. There may be different shapes than you saw the day before. Draw
pictures of what you saw in the boxes provided below.
Wash your hands thoroughly. Place the slide cover in the garbage. Wash the
slide in hot, soapy water with several spoonfuls of liquid bleach added. Ask
your parents to help you because bleach can hurt you, and the bottle is heavy.
Wash your hands again.
Notes:
Friendly Bacteria
Other Bacteria
Содержание MicroPro EI-5301
Страница 1: ...EI 5301 Grades 3 Ages 8...
