Development of the Plant World on Earth
Answers are for parents and teachers.
1
Draw a timeline of plant evolution.
Algae → psilophytes → moss/horsetail/fern → gymnosperms → angiosperms.
2
Why did angiosperms become dominant? Write 3 reasons.
Seed protected in fruit, double fertilization, insect pollination, adaptation to varied habitats.
3
List 5 plant families from the course with one representative each.
Rose — apple; mustard — radish; legume — bean; nightshade — tomato; grass — wheat.
4
A tree fern 25 m tall; how long are 3 such trees laid end to end? (25 × 3)
75
5
Why are photosynthesizing algae thought to have raised oxygen in Earth’s atmosphere?
Photosynthesis releases oxygen; over billions of years it accumulated in the atmosphere.