Directions: To answer the following questions, study the following resources: your lecture materials, and pages 224-228 (“Life cycle of a moss” and “Life cycle of a fern”).
1. Describe the move of plants onto land. What challenges did plants need to overcome in order to successfully live & reproduce on land? What adaptations allowed them to overcome these challenges?
The moss lifecycle
Step 1. A tiny spore blows in the wind, lands in moist soil, and sprouts into a leafy plant.
Step 2. At the top of the moss plant, hiding within its leaves, eggs form within little cups. Neighboring moss plants make sperm inside little sacs.
Step 3. The eggs give off chemicals to beckon the sperm who swim within a film of rain water.
Step 4. The fertilized egg (zygote) sprouts into a tall stalk, up into the air currents. At the tip of the stalk is a capsule where spores are made via meiosis and released into the wind.
Moss questions based upon the story above:
2. Does “sprouting” happen via mitosis?
3. Are moss gametes (eggs and sperm) made via meiosis as they are in animals?
4. The spores are made via meiosis… so are the spores haploid or diploid?
5. The leafy plants are made from a sprouted spore… so are the leaves haploid or diploid?
6. How is spore different from a gamete?
7. How does moss get up onto your roof?
FERNS ….will represent the SEEDLESS VASCULAR PLANTS
Their story sounds a lot like the moss story… with a few subtle twists.
A. The Fern lifecycle
Step 1. A tiny fern spore blows in the wind, lands in moist soil, and sprouts into a little heart-shaped flat thing.
Step 3. The eggs give off chemicals to beckon the sperm who swim within a film of rain water (from one “heart” to another).
Step 4. The fertilized egg (zygote) sprouts into a leafy fern plant. On the surface of the leaves, many spore capsules form. Spores are made via meiosis and tossed into the wind.
Questions based upon the life cycle story
8. Is the flat heart-shaped thing diploid or haploid?
9. Are the fern leaves haploid or diploid?
10. Where would you find fern zygotes?
11. What is the “job” of a fern spore?
12. What is the technical name for the heart-shaped thing?
13. What is the technical name for the stage when ferns have roots, stems, leaves and spore capsules?
14. What is the technical name for spore capsules?