Standard 2/Middle School/Benchmark 2
Benchmark Question: What are the life cycles of living
Focus Question: What are the predictable stages of
the life cycle of a flowering plant?
Students will dissect a
variety of flowers to observe their structures. Dissection should be done
carefully and sequentially, so structural parts are kept together. Students
should then place a sheet of black construction paper on a table and gently
tap the flower to collect pollen on the paper. They should examine the
pollen under the microscope.
Specifically, they should:
1. Remove the petals and sepals to allow for closer
2. Examine the pollen-producing structures (stamens) and
remove them carefully
3. Observe the remaining ovary structure by carefully
slicing the ovary vertically in half. (Because this is a mature flower,
fertilization has already taken place, meaning that the egg and sperm have
already united and formed the tiny seeds they may see.)
Students should then discuss
the role the flower plays in the life cycle of a plant. They should examine
a variety of seeds, such as a lima bean, to observe the embryonic plants
inside. They should hypothesize which areas will develop into the roots,
stem(s), and leaves.
Then the students should
design an investigation to determine what effect one variable might have on
the life cycle of a flowering plant (e.g., photo-period [amount of
sunlight], temperature, soil composition, water, fertilizer, competition
[number of plants], acid rain).
for the Investigation
you clearly stated the problem you investigated?
variables did you investigate?
your instructions for each step written clearly and completely enough so
that someone else could easily replicate your investigation?
your data organized in a table, chart, or graph?
your tables, charts, or graphs properly labeled?
your conclusions fully supported by your data?
valid are your conclusions or results?
specific ways could your experiment be improved?