Download Plant Anatomy and Physiology

Plant Anatomy and PhysiologyRoots!
What do these have in common?
That’s right!
They are all parts of a plant!
Major Parts of Plant
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Roots
Stem
Leaf
Flower
Fruit/Seed
Student Learning Objectives
• Distinguish between the types of root systems
• Explain how nutrients and water are absorbed
through roots
• Explain why root systems are essential in soil
conservation
Roots
• Serve as foundation of plant by:
– Absorbing water and nutrients
– Storing food
– Anchoring the plant to support above ground
parts of plant
Root Systems
• Tap: A root system composed of one primary
root and many secondary roots that branch
off.
• Fibrous: A system that has no dominant
primary root.
Tap
Fibrous
• Tap roots can reach great
depths in their root
systems while fibrous
root systems stay closer
to soil surface.
Roots
• Primary Root: First root to emerge at
germination.
– May become main tap root
• Secondary Roots: Roots that branch out from
primary root.
Healthy vs Unhealthy Roots
• Healthy roots are white or nearly white and
smell fresh.
• Unhealthy roots are black, brown, dark orange
and smell rotten.
Student Learning Objectives
• Distinguish between the types of root systems
• Explain how nutrients and water are absorbed
through roots
• Explain why root systems are essential in soil
conservation
Nutrient Absorption
• Water and nutrients are taken in by small, fine
roots called root hairs.
• Water and minerals enter root hairs through
osmosis and diffusion.
Osmosis and Diffusion
• Diffusion– Movement of mineral molecules from area of high
concentration (nutrients in soil) to areas of low
concentration (roots).
• Osmosis– Is a type of diffusion dealing specifically with
water. Water passes through semi-permeable
membrane (cells) to then move through plant
cells.
Osmotic Pressure
• The movement of water through osmosis
creates a pressure within the plant called,
osmotic pressure.
• This build-up of pressure is what allows water
to move within the plant.
Student Learning Objectives
• Distinguish between the types of root systems
• Explain how nutrients and water are absorbed
through roots
• Explain why root systems are essential in soil
conservation
Root Nodules
• Some plants provide their own nitrogen
nutrients through a symbiotic relationship
with rhizobium bacteria.
(Symbiotic relationship – two organisms live together and
both benefit)
Root Nodules
• Rhizobium Bacteria invade the root hairs of
plants.
• Plants respond by creating a nodule to
surround the bacteria.
Root Nodules
• The bacteria takes nitrogen from the
atmosphere and combine it with oxygen to
form NO3 (Nitrate) and NH4 (Ammonium).
• The plant is able to then use these forms of
nitrogen.
Legumes
• We call these plants who have this
relationship, Legumes.
– Legumes include: soybeans, clover, beans, peas
and alfalfa.
Roots & Soil Conservation
• Roots hold soil in place and help to prevent
erosion.
• By using legume plants in crop rotations, less
nitrogen is needed to be added each year.
Student Learning Objectives
• Distinguish between the types of root systems
• Explain how nutrients and water are absorbed
through roots
• Explain why root systems are essential in soil
conservation
What questions do you have?