Transcript Lecture 1 Plant Structure

Lecture 1 – Plant Structures
Objectives
• Outline the main parts of a plant.
• Explain how plants are designed.
• Describe the functions of plants.
Animal or Plant?! The sea slug, Elysia chlorotica, captures chloroplasts from the
algae on which it feeds. In addition, it has recently been shown to also have
incorporated into its genome some of the genes necessary for photosynthesis to
continue in these sequestered chloroplasts. True “green technology” in action to
produce a solar powered animal!
1. Write a brief paragraph to explain, what is a plant? Be
sure to mention the life cycle
2. World population has increased dramatically in recent
times. What has happened to grain production during this
time? Has it increased, decreased or stayed the same?
Compared to the increase in world population, is there:
(a) enough; (b) large surpluses or (c) large deficits
in food needed to feed everyone?
Plant Engineering and Design
What does a plant need to do?
1. Attachment to ground
2. Water uptake
3. Photosynthesis (food production)
4. Material transport
5. Reproduction:
- pollination
- seed dispersal
Plant Engineering and Design
Plants have a modular design:
Organs, Tissues, Tissue Systems
•
Roots
•
Stems
•
Leaves
•
Flowers (=modified stem + leaves)
•
Fruit + Seed
Roots
Primary Functions:
1. Attachment to substrate
2. Water and nutrient uptake
3. Transport of water and food
4. Food storage
Roots
Primary Functions:
1. Attachment to substrate
2. Water and nutrient uptake
3. Transport of water and food
4. Food storage
Major Functions of Roots
Root Systems
Roots First
See Fig. 1.6, p. 7
Roots First
Roots First
Mycorrhizae
Adventitious
Roots
Big Adventitious
Roots = Buttresses
Adventitious Roots – Used for Propagation
Storage Roots
The Shoot System
- Stems
The Shoot System
- Stems
nodes + internodes
The Shoot System
- Stems
nodes + internodes
- Leaves
The Shoot System
- Stems
nodes + internodes
- Leaves
blade + petiole
The Shoot System
- Stems
nodes + internodes
- Leaves
blade + petiole
- Buds
Stems – Functions
- Supportive Framework: Leaves and Flowers
- Conduction of food and water
Stems – Functions
- Supportive Framework: Leaves and Flowers
- Conduction of food and water
Design Constraints:
- Growth, from point source
- Cellular composition
Stems – Functions
- Supportive Framework: Leaves and Flowers
- Conduction of food and water
Design Constraints:
- Growth, from point source
- Cellular composition
Result: Mostly cylindrical structures and substructures
Stem –
Cylindrical
Structure
Stem –
Cylindrical
Structure
Vascular
Bundle
Pith
Specialized Stems
Leaves - Functions
1. Food production (Photosynthesis)
Leaves - Functions
1. Food production (Photosynthesis)
- Light absorption
- Gas exchanges
- Food and nutrient transport
Leaves - Functions
1. Food production (Photosynthesis)
- Light absorption
- Gas exchanges
- Food and nutrient transport
2. Specialized functions in some plants
Leaf – Structure
Leaf – Structure
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FOR YOUR ATTENTION