Question

identify the locules, seeds, and pericarp. Compare this to the cross section of the lily ovary.

Answer 1

Flowers, Fruits, and Seeds Lab Report
What you will need to do this lab:
· gladiolus or lily
· apple
· tomato
· green pepper
· bean pod or pea pod
· sunflower seed
· bean seed soaked overnight in water
· corn seed soaked overnight in water
· magnifying glass
· razor blade (be careful!!)
· potassium iodide tablets from pharmacy.
Obtain a flower. (Preferably a large gladiolus or lily, but NOT a sunflower,
carnation, or daisy) you have bought from your local grocery store or picked from
your own garden. You will need to know the identity of the flower. If possible,
take several digital photos of the flower as you dissect it.
Make a sketch of the flower you have and identify its parts. If you could not get a
flower, use the flower pictured in course lab instructions.
Sketch or picture of Flower with parts labeled.
Name of flower: ____________________
· How many petals does this flower have?
· How many stamens does this flower have?
· How many stigmas does this flower have?
· Is this the flower of a monocot or a dicot? How can you tell?Is this
consistent with the structure of the leaves of this plant? Explain.
Perfect flowers have both stamens and pistils, while flowers lacking either stamens
or pistils are termed imperfect (i.e., there are separate male and female flowers in
imperfect plants while perfect flowers are bisexual).
· Is this flower perfect or imperfect?
· How many locules are in this ovary?
· Is this consistent with your earlier conclusions about the classification
of this plant as a monocot or dicot?
1) Obtain an apple. Apples, pears and quince are classified as pomes.
2) Cut a cross section of the apple and compare it to your cross section of the
ovary.
3) Obtain a tomato. Tomatoes, oranges and peppers are all classified as
berries.
4) Cut crossways through a tomato and locate the seeds, locules, and pericarp.
Tomato plants have superior ovaries (located “above” the other flower parts).
· Where would you expect to find the withered sepals and petals on a freshly
picked tomato?
· How about the style and stigma?
· How does this compare to the apple fruit?
1) Cut a cross section through a green pepper.
2) Make a sketch and identify the locules, seeds, and pericarp. Compare this to
the cross section of the lily ovary.
Lily (Gladiolis) ovary sketch
Pepper sketch
1) Obtain a bean pod or pea pod. The bean pod is a fruit (mature ovary)
containing seeds in spaces called locules.
2) Find the placentae for the bean seeds. The bean pod represents the mature
pericarp. Beans and peas are classified as legumes.
3) Make a cross section of a bean pod and examine it under a magnifying glass.
Notice that the wall of the fruit (the pericarp) can be divided into three layers:
the lining of the pod (endocarp), the juicy mesocarp and the tough outer exocarp.
Bean Pod sketch
· Bean plants have superior ovaries. Where would you expect to find the
withered sepals and petals on a freshly picked bean pod?
· How about the style and stigma?
· How does this compare to the tomato fruit?
1) Obtain a sunflower seed. Sunflower “seeds” are fruits classified as achenes.
The “shell” of the sunflower seed is actually the pericarp. In this case, it is dry
rather than being fleshy. The true seed (fertilized ovule) is inside the pericarp.
2) Open up the pericarp to locate the seed, locule and placenta. Sunflower
seeds are the fruits of a composite flower; each little disc flower produces a
single fruit.
1) Obtain a presoaked bean seed (kidney beans are sold in bulk or dry in many
grocery stores; the directions below refer to the kidney bean) that you had placed
into a glass of water the day before doing this part of the lab.
2) Remove the brown seed coat and carefully separate the two halves of the seed