BIOLOGY EXPERIMENTS CHILDREN

(Jacob Rumans) #1
You will observe:Manylargebacteria.

Bacteriathatare inactive are alwayspresentin a spore form in the air
and on objects bothliving and nonliving. The spore form is similar to the
state ofhibernation thatthe bearand frog sink into tocarry them over a
cold winter.
Bacteriaofdecay develop protectivespore coats aroundthemselves until
theconditionsfor growing are good. To grow,bacterianeed food,moisture,
darknessandwarmth. They find theseconditionsin living plants andanimals
thathave died and have beenburiedin theground,or in water.


The bacteriaof decay then break throughtheir hard, protective spore
coats and startto feed and grow. The dead plantand animal tissuesupon
which they feed arebrokendown into theiroriginalelements and compounds.
This process is known as decay. Usually an offensiveodoraccompaniesdecay.
This is due to gasesthatare given offduringthebreakingdown process.

STUDYING SIMPLE FRESH-WATER PLANTS- ALGAE
Materials:Awide-mouthedglassjar,dilute iodinesolution,and a medicine
dropper.
Follow this procedure:Collect water from apondin awide-mouthedglass
jar. Keep this at roomtemperature. Expose thejarofpondwaterto the
sunlightfor severalhourseach day for a week.
Thenplace adropofpondwaterculturein the middleofa clean glass
slide. Add to it adropofdilute iodine. Place a cover slip carefully over the
dropson the slide.
Observe first under low power, and then under high power ofyour
microscope.
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