Discussion
Questions
1. What
is a bulb? (A plant that grows from an underground mass
of food storage tissues. This mass is also called a bulb.)
2. What
are the parts of a bulb and what is their function? (embryonic
leaf, stem, and flower parts – develop into leaves, stem,
and flowers; fleshy scales -– provide food for the young
plant; basal plate – produces roots; tunic – serves
as protective
outer layers)
3. Do all plants have the ability to store
enough food for one growing season?
(No. For instance, annual plants focus on producing seeds and then die.)
4. What are some of the benefits to a plant with this food
storage capacity?
(It's a survival mechanism that gives a plant enough stored food to survive
at least one season in poor environmental conditions.)
In-Class
Activity: Flower Dissection
* Note: Some
people experience skin irritation from handling bulbs, so make
sure students wash hands thoroughly after planting or wear gloves
while planting.
1. Introduce
students to bulbs using the details provided in the Background
Information. Talk about their unique ability to store enough energy
to produce leaves and flowers for the next growing season.
2. Show students the example bulbs. If possible, have various
types of bulbs (onions, tulips, daffodils, hyacinths, and paperwhites) so they
can compare and note similarities and differences. Ask them to describe what
each looks like from the outside. Instruct them to draw a picture of each type.
3. On the chalkboard or dry erase board, draw an outline of the parts of a bulb
on the board. Talk about the different parts and what they do (see
Background
Information).
4. Cut sample bulbs in half (you can either use onions from the grocery store
or spring-flowering bulbs if they are available). Place the bulbs in plastic
bags* and then give students a chance to view the cut bulbs. It's
best
to
have
enough bulbs for students to each have their own to work with; aternately, have
them share in
small groups.
5. Ask students to draw the inside of the bulbs and then label the different
parts. Depending on the maturity of the bulb and the conditions it has been exposed
to, they may be able to clearly see the young leaves and flowers.
If you do not see any leaves or flowers in this batch of bulbs, try to find some
more mature bulbs so they can see the difference.
Extensions
Science - As the students discovered in the botany
lesson, the roots of the bulb grow from the basal plate and the
shoots
grow above
the basal plate. So does it matter which end is up when planting?
Ask
students to hypothesize what they think is the best planting method
for a bulb, and then as a class plant a few bulbs facing different
directions. Observe the bulbs for several weeks and keep a journal
of their growth. After several weeks, compare the results and
make a conclusion about the hypothesis. The students should find
that
bulbs planted upside down use a lot of energy growing around the
bulb and up and so they may not survive and/or bloom.
Math - Plant several bulbs in pots (see Background
Information for information on forcing bulbs, or use paperwhites).
Measure the plants daily as they grow (metric and English measure)
and
then chart the data on a
graph. Discuss the growth patterns observed.
.
English - Read the book A Flower Grows by Ken Robbins (Dial Books,
New York, NY1990) detailing the growth of an amaryllis bulb. Plant an amaryllis
in the classroom and compare the observed growth with the book.
Art - Make a color wheel using pictures
of bulb flowers cut from catalogs. Discuss the concepts of primary, secondary,
and
complementary
colors.
.
History/Economics - Read about “tulipmania” in the Plant
of the Month. Discuss
the effects of supply and demand on prices. Introduce the concepts of trade markets,
speculation, and inflation.
