1. Adaptations of Land Plant Prof. Ms. Vrushali S
Adaptations of Land Plant Prof. Ms. Vrushali S. Dighe Department Of Botany S. M. Joshi College, Hadapsar, Pune.

2. Offspring develop from multicellular embryos that remain attached to the “mother” plant for protection and nourishment.
Vascular tissue is present in all but the bryophytes ( some of these have some type of transport vessels but lack TRUE roots, stems and leaves.

3. There are four main groups of land plants
Bryotphytes – mosses
Pteriodophytes – ferns
Gymnosperm – conifers
Angiosperms – flowering plants

4. Charophyceans are the green algae most closely related to land plants

5. Features that distinguish land plants.
Plasma membranes containing rosette cellulose – synthesizing proteins
Peroxisomes – help maximize the loss of organic products due to photorespiration.
Flagellated sperm are similar
Cell division – formation of phragmoplast

6. Five Characteristics Unique to Land Plants
Apical meristem – localized regions of active cell division in roots and shoots
Embryophtes – multicellular dependent embryos
Alternation of Generations
Walled spores produced in sporangia
Multicellular reproductive structures – antheridia and archegonia

7. What Is a Plant?
Multicellular eukaryotes that are photosynthetic autotrophs
Cell walls made of cellulose
Store surplus carbohydrates as starch
Mostly terrestrial

8. Terrestrial Adaptations Are Complimented by Chemical Adaptations
Secondary products
Synthesized by side branches of main metabolic pathway
Many protect the plant against excessive damage by herbivores
Examples
Cuticle
Lignin
Sporopollenin

9. Reproduction Plants produce their gametes within GAMETANGIA
Zygote develops into an embryo within a jacket of protective cells
Embryophytes – a key adaptation to the success of plants on land

10. ALTERNATION OF GENERATIONS
Occurs in life cycle of all plants
One generation is a multicellular haploid condition and the next is a multicellular diploid condition

11. Obstacles Plants Overcome
Absorb Minerals
Conserve Water
Cuticle
Stomata
Guard Cells
Reproduce on Land

12. A Vascular System Enables Plants to Thrive on Land
Most plants need a “plumbing” system to transport water, minerals and nutrients. This system is known as the VASCULAR SYSTEM.

13. Plants are monophylogenetic

14. Key to Modern Plant Diversity
There are four main periods of plant evolution. Each period was an adaptative radiation that follow the evolution of structures that open the new opportunities on land.
The first terrestrial adaptations included spores toughened by sporopollenin and jacketed in gametangia that protect the gametes.

15. The second major period was plant diversification in the Devonian period – earliest vascular plants lacking seeds
The third major period of evolution was the origin of the seed.
The fourth was the emergence of flowering plants.