2. • Botany is the study of plants.
• Areas of botany:
– Plant Anatomy and Physiology
– Plant Taxonomy
– Plant Geography
– Plant Ecology
– Plant Genetics
– Plant Cell Biology
– Economic Botany
– Ethnobotany
What is botany?
20. Cont’d
•Plants also grouped according to how they
obtain water.
•Vascular plants have tube-like structures that
transport water from the roots to the leaves.
•Nonvascular plants can only absorb water
through their roots.
21. Nonvascular plants
•Nonvascular plants or bryophytes are
found in moist areas because they do not
have long roots to absorb water.
•They are usually less than 20 cm tall.
•Three classes:
•Mosses
•Liverworts
•Hornworts
23. Cone-bearing plants
760 species
Ferns and
their relatives
11,000 species
Mosses and
their relatives
15,600 species
Flowering
plants
235,000 species
Section 22-1
Figure 22-7 The Diversity of Plants
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Section:
24. Cont’d
•Plants also grouped according to how they
obtain water.
•Vascular plants have tube-like structures that
transport water from the roots to the leaves.
•Nonvascular plants can only absorb water
through their roots.
30. Angiosperms
Commonly called flowering plants
Two types:
monocots – one seed leaf
dicots – two seed leaves
Fruit – ripened ovary of a flower
Includes trees, grasses, and shrubs
31. First Plants
•Oldest fossils (450 million years) show that
earliest plants were similar to today’s mosses
•Early plants depended on water for
reproduction
•Over time plants evolved adaptations that
allowed them to reproduce without water and
also to exist in a wide range of terrestrial
environments.
32. 1. First plants evolved from multicellular
green algae.
2. These algae have the size, color,
appearance of plants
3. Reproductive cycles of algae like plants
4. Cell wall and pigments of algae identical
to plants
Origins in water
