10.2
Warm up
 What is a prokaryote?
 Give some examples where you might find
bacteria.
 Which one is more important: prokaryotes or
eukaryotes?
Objectives
 Explain how life on Earth depends on bacteria.
 Describe the process of nitrogen fixation.
 Define bioremediation.
 List three ways bacteria are useful to people.
 Describe two ways in which bacteria can be harmful
to people.
Introduction
 Are harmful bacteria more of a problem or less of a
problem to people now than they were 200 years ago?
 Can you name some products that are made by using
bacteria?
 Have you ever had strep throat or a cavity in your
tooth?
Bacteria in the environment
Good for the environment
 Life as we know it could not exist without bacteria.
Bacteria are very important to health of Earth. They
help recycle dead organisms. Bacteria also play an
important role in the nitrogen cycle.
 Bacteria are important to life on Earth because
1- they fix nitrogen
2- they decompose dead matter.
Nitrogen fixation
Recycling
Bioremediation
 Bacteria and other microorganisms are also used to
fight pollution.
 Bioremediation: using microorganisms to change
harmful chemicals into harmless ones,
 Bioremediation is used to clean hazardous wastes from
industries, farms and cities as well as oil spills.
Good for people
 Bacteria are useful to people because they help make
foods and medicines (antibiotics: medicines used to kill
bacteria ex: insulin).
Genetic engineering
 The process of changing the genes of an organism is
called genetic engineering.
 Scientists can now engineer bacteria to make many
products, such as insecticides , cleansers and adhesives.
Pathogenic bacteria
 Pathogenic bacteria = harmful bacteria
 They cause diseases
 Pathogenic bacteria get inside a host organism and take
nutrients from the host cells as well as they harm the
cells of the host. Today, we are protected from many
bacterial disease by vaccination or antibiotics.
Pathogenic bacteria
 Pathogenic bacteria can also cause diseases in animals, plants,
fungi and even other bacteria.
 It can harm fruits, seeds and crops.
Wrap up
 How life on Earth depends on bacteria?
 Describe the process of nitrogen fixation.
 Define bioremediation.
 List three ways bacteria are useful to people.
 Describe two ways in which bacteria can be harmful
to people.
Assignments
Section review questions
page: 225 # 1 - 6
SWQ1: 5.1, 5.2, 10.1