Question

1. As you are walking through the woods with a friend, you notice some ferns growing along the path. When you stop to examine them, you note that there are brown bumps on the underside of the leaf, which you believe to be either some kind of fungal disease or insects. Your friend says that the bumps are normal. Who is correct? Explain

2. Describe where pollination and fertilization occur beginning with production of the pollen grains and ending with the sperm nuclei reaching the egg nucleus. Be specific and detailed.

3. How can someone tell if the pollen sacs are open? How would someone know if the stigma is mature? Be specific.

4. Seeds come from which part of the flower? Fruit is what part of the flower? The embryo comes from which part of the flower?

5. Explain how pine cones and strobili are different.

Answer 1

1.
The brown bumps on the abaxial surface of fern leaves are normal.
They represent reproductive structures known as sporangia.

2.
1. Formation of egg cell in the embryosac of the ovule (Located in the ovary)
2. Formation of pollen in the pollen sac of the stamen.
3. Pollination
4. Germination of the pollen
5. Mitotic division of pollen nucleus to produce vegetative and reproductive cells.
6. Reproductive cell undergoes one mitotic division to produce two nuclei
7. One nucleus fertilizes egg cell to form zygote
8. The second nucleus fertilizes central cell to form triploid primary endosperm nucleus.

3.
Yes.
Opened pollen sacs exhibit powdery appearance.
Matured stigma is often bulgy and shows expanded stigmatic papillae.

4.
Seeds develop from the fertilized ovule.
Fruits develop from the ovary.
Embryo comes from the zygote (Fertilized ovule).