Lecture Outline for April 18, 2005


Topic: plant nutrition

Chapter 27 section 27.1

Figures used in lecture: 27.1, 27.2, 27.5

Figures used in lecture that are not in your textbook REQUIRES POWER POINT


Additional Resources:

            Nitrogen Fixation and Rhizobium

            What is Plant Nutrition?


Plant Nutrition

Define/explain: essential nutrients, macronutrients, micronutrients, nitrogen fixation, symbiosis, mutualism, legumes, rhizobia, epiphytes, parasitic plants, carnivorous plants


You should be able to:

1. Describe the three properties of an essential nutrient

2.  Understand the difference in function of the macronutrients and the micronutrients

3.  Explain why nitrogen fixation is important to all organisms in the biosphere

4.  Explain how each member of the mutualistic relationship between plants and rhizobia benefits.

5.  Define and give examples of alternate mechanisms plants use to obtain nutrients such as epiphytic plants, carnivorous plants, and parasitic plants.


Today’s Lecture (4-18-05)

Plant Nutrition

Essential nutrient –

            1.  required for growth or reproduction

            2.  no other element can substitute for it

            3.  required for a specific structure or metabolic function







Nitrogen Fixation

Q. Why do organisms need nitrogen?


Nitrogen in atmosphere is N2.

Very few organisms possess the enzyme required to break N2.

Nitrogen fixation:



Eg., Rhizobium sp. (aka rhizobia)

Form an association with the roots of legumes








Alternative Mechanisms of Plant Nutrition

1.  Epiphytes



2.  Carnivores



3.  Parasites