with water, temperature, and light to see what makes
a seed come out of its shell.
Do I Need?
3 black 35-mm film canisters, with lids
o a paper towel cut into 1-cm x 4-cm strips
o 9 seeds each of cabbage, radish, and parsley
Do I Do?
Add water to just cover the bottom of each film canister.
Insert three paper towel strips into each of the canisters,
tipping the canister to moisten the strips.
Divide nine cabbage seeds among the three strips in one canister,
nine radish seeds in the second, and nine parsley seeds in
Put the lids on the canisters. Label each canister with seed
type, date, and time. Check your seedlings every day. If they
havent germinated within a week, try changing the temperature
or moisture, or opening the canister lids to add light (just
add one variable at a time), and record your changes.
all seeds serve the same purposepassing genes and new
life from one generation to the nextmost require unique
conditions to do so. When the proper environmental conditions
appear, the seed
germinates, or sprouts. Some seeds prefer darkness while others
prefer heat to germinate, but they all need water. Water triggers
germination, causing the seed coat to expand and rupture,
allowing the plant embryo inside to emerge and resume growth
and radishes are fast germinators (usually within five to
seven days) that need light and warmth to germinate. Parsley
is notoriously difficult to germinate, and may take up to
a month to sprout.
with different methods:
your seeds don't sprout, try presoaking them in warm water
overnight, storing them in a moist paper towel away from the
light, or invent your own method to coax these recalcitrant
seedlings out of their shell.
SECTIONS: The Stuff of Life,
Life Needs Energy, Making
More Life, Change Over Time
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