1. LESSON PLAN
SUBJECT: BIOLOGY
CHAPTER NO: 9
UNIT: LIFE UNDER MICROSCOPE
TOPIC: OCCURRENCE OF MICROORGANISM
CLASS: VII (ICSE) DURATION: 35 MINUTES
TEACHING POINTS:
Occurrence of microorganisms.
Bacteria: occurrence, structure, size, shape, nutrition, growth and reproduction.
INSTRUCTIONAL OBJECTIVES:
The students will be able to:
1) Knowledge:
Define microorganisms.
Recognize the different types of microorganisms.
Recall the occurrence, structure, size, shape, nutrition, growth and reproduction of bacteria.
2) Understanding:
Identify unicellular and multicellular microorganisms.
Give examples for unicellular and multicellular microorganisms.
The occurrence, structure, size, shape, nutrition and reproduction in bacteria.
3) Skill:
Draw a neat labeled diagram of bacteria structure.
4) Application:
Create a proper environment for the growth of useful bacteria and also find out remedies to stop growth of harmful bacteria.
2. TEACHING AIDS:
1) Chart on bacteria structure.
2) Images on different shapes of bacteria.
3) Black board work.
4) Power point presentation for evaluation and home work.
REFERENCE:
ICSE textbook of St. Francis ICSE School.
PREVIOUS KNOWLEDGE TEACHER ACTIVITY STUDENT ACTIVITY
INTRODUCTION:
We have studied about nature and what all it
consists of?
Teacher greets the students.
What all can we see through naked
eyes?
What all cannot be seen through
naked eyes?
Through which the bacteria, viruses
can be seen?
Who is the founder or discoverer of
microscope?
Students greet the teacher.
Human beings, trees, buildings etc.
Microorganisms like bacteria viruses
etc.
Microscope
No response.
STATEMENT OF AIM:
In today’s class let’s study about the occurrence of microorganism, types of microorganism and characteristics of bacteria from the unit Life
under microscope.
3. CONTENT TEACHING POINT TEACHERS ACTIVITY STUDENT
ACTIVITY
EVALUATION
Organisms can be seen
only through a
microscope are called
microorganism or
microbes.
Microorganism or
microbes
Teacher explains, some living organisms are large in
size and visible to us. On the other hand there are
many living organisms which are so small that we
cannot see them with our naked eyes. Such organisms
can be seen only through a microscope and are called
microorganisms or microbes.
Students listen
. Anton van
Leeuwenhoek
discovered
microorganisms.
. Found in water, air,
soil, food as well as in
bodies of plants and
animals. Found in hot
water springs, desert as
well as in freezing
condition.
Occurrence of
microorganisms.
Teacher explains, Anton van Leeuwenhoek, a Dutch
scientist, was the first to discover microorganisms in a
drop of water. By showing photo of Anton van
Leeuwenhoek.
Microorganisms are found almost everywhere. They
are found in hot water, air, soil, food as well as in the
bodies of plants, human beings and animals. They are
also found in hot water springs, deserts as well as in
freezing conditions. They play a very important role in
our life. Some are beneficial to us whereas others can
be extremely harmful to us.
Students listen
Who discovered
microorganisms?
Ans: Anton van
Leeuwenhoek.
Unicellular- single cell.
Multicellular- many
cells.
Unicellular and
multicellular
microorganisms.
Teacher explains, microorganisms which are made up
of only one cell are called unicellular microorganisms.
E.g. bacteria, algae, yeast (fungus), protozoans.
Whereas microorganisms which are made up of more
than one cells are called as multicellular
microorganisms.
E.g. spirogyra, bread mould and volvox.
Students listen
Give examples of
unicellular and
multicellular
microorganisms.
Ans: unicellular-
bacteria , algae,
yeast, protozoan
Multicellular-
spirogyra, bread
mould and volvox.
4. CONTENT TEACHING POINTS TEACHERS ACTIVITY STUDENTS
ACTIVITY
EVALUATION
Bacteria, Algae,
Protozoa, Fungi and
Viruses are the five
major groups of
microorganism.
Five major groups
of microorganism.
Teacher explains, there are five major groups of
microorganisms. They are as below: Bacteria, Algae,
Fungi, Protozoa and Viruses.
Students listen
List the five major
groups of
microorganism?
Ans: Bacteria, Algae,
Fungi, Protozoa and
Viruses.
Bacteria are
unicellular, minute
microbes.
Bacteria Teacher defines; bacteria in singular form called as
bacterium are minute, unicellular microbes. They are
perhaps the first organism to inhabit earth.
Students listen
Found in water soil,
water, sewage water,
oceans streams etc.
Occurrence of
bacteria.
Teacher explains; bacteria are present almost
everywhere. They are found in air, soil, water, sewage
water, oceans, streams, snow, hot springs, decaying
matter, food and even in our alimentary canal.
Students listen
Single celled, cell wall,
cell membrane,
protoplasm, no
definite nucleus,
hereditary material is
scattered.
Structure of
bacteria
Teacher explains by showing a chart that has image of a
bacteria structure, a bacterium is typically single celled
hence they are unicellular microorganisms. It has a cell
wall, cell membrane and protoplasm. The hereditary
material is scattered in the cell. Organelles such as
mitochondria, plastids, and ribosomes are absent. Most
bacteria cannot move but some have flagella for their
locomotion.
Students listen
and observe
carefully.
0.2 to 100 microns Size of bacteria Teacher explains, bacteria, are among the smallest and
simplest organism on earth. The size of an average
bacterial cell varies from 0.2 to 100 microns (1 microns=
1/1000 of millimeter.)
Students listen
What is the average
size of bacteria
varies from?
A: 0.2- 100microns
5. CONTENT TEACHING POINTS TEACHERS ACTIVITY
STUDENT
ACTIVITY EVALUATION
Shapes of bacteria-
Cocci- spherical
shaped bacteria.
Bacilli- rod shaped
bacteria
Spirilla- spiral shaped
bacteria
Vibrios- comma
shaped bacteria.
Shapes of bacteria Teacher explains by showing the images on shapes of
bacteria, on the basis of their shape bacteria are
classified into four different types:
Cocci: they are spherical shapes of bacteria. They may
occur as single cells (monococcus), in pairs
(diplococcus), in chains (streptococci), in clusters
(staphylococci). Bacterial pneumonia is caused by cocci
bacteria.
Bacilli: are rod shaped bacteria. Some of these grow in
form of chains too. Ex. Escherichia coli which lives in
human intestine that is they are parasitic
microorganisms.
Spirilla: are spiral shaped bacteria. They exist as single
cells only. Some spirilla enrich the soil.
Students listen
Students listen
and observe
Students listen
and observe
Students listen
and observe
6. Vibrio’s: are short, curved or comma shaped bacteria.
For example, vibrio cholera which causes cholera in
human beings.
Students listen
and observe.
Bacteria can be
heterotrophic,
saprophytic or
parasitic. Some may be
autotrophic.
Nutrition of
bacteria
Teacher explains, bacteria can grow and feed on almost
any type of matter. Most bacteria lack chlorophyll,
hence, cannot prepare their own food. They depend on
other sources for their food. These bacteria are
heterotrophic. They can also be saprophytic or parasitic.
But there are some bacteria which are autotrophic as
they are capable of preparing their own food.
Cyst, 25⁰C - 40⁰C,
grows best in darkness,
needs moisture,
aerobic bacteria and
anaerobic bacteria
Growth of bacteria Teacher explains, ..Bacteria can grow in almost all
conditions. Most bacteria can survive under extreme
conditions by forming a hard protective covering around
them called as cyst. They remain inactive in the cyst
during unfavorable conditions.
.Bacteria grows best between 25⁰C-40⁰C. Some can
grow at a very high or low temperature.
.They grow best in darkness. Sunlight kills many kinds of
bacteria.
.Bacteria need moisture for their growth, otherwise
they become inactive.
Certain bacteria need oxygen to grow. They are called as
Aerobic bacteria. Ex, tuberculosis causing bacteria.
Those that can grow in absence of oxygen are called
Anaerobic bacteria. Ex, Bacteria that causes tetanus and
lockjaw
Students listen
Bacteria have a hard
protecting covering
around them called
us?
Ans: Cyst
What is the
optimum
temperature
required for growth
of bacteria?
Ans: 25⁰C - 40⁰C
7. Bacteria reproduce by
binary fission.
Reproduction in
bacteria.
Teacher explains, under favorable conditions Bacteria
reproduce fast. They divide by binary fission, in which
one bacterial cell divides into two daughter cells.
Students listen
CONCLUDING STATEMENT:
Today we have studied about microorganisms, its occurrence, and its types. Bacteria- occurrence, structure, size, shape, nutrition, growth and
reproduction.
RECAPITULATION AND BLACK BOARD SUMMARY:
RECAPITULATION BLACK BOARD SUMMARY
Founder of microorganism?
Give examples for unicellular and multicellular
microorganism?
What are bacteria?
What is the size of bacteria?
What are the different shapes of bacteria?
Anton van Leeuwenhoek is the founder of microorganism. Unicellular are made up
of only one cell. Ex; bacteria, algae, protozoa and yeast. Multicellular are made up of
many cells ex; spirogyra, bread mould. Bacteria are minute unicellular microbes. The
size of bacteria varies from 0.2-100 microns. The different shapes are cocci, bacilli,
spirilla and vibrios. The optimum temperature required for the growth of
microorganisms varies from 25⁰C-40⁰C
EVALUATION:
1) GIVE ONE WORD ANSWER:
a) Comma shaped bacteria is called as -
b) Rod shaped bacteria is called as -
c) organisms that can be seen only through microscope are called as -
2) FILL IN THE BLANKS:
a) The ______________ material is scattered in bacterial cell.
b) Bacterial cell size varies from ______ to _____ microns.
c) Bacteria have a protective covering around them are called as _______________.
d) The optimum temperature required for growth of bacteria is ____________________.
KEY ANSWERS:
HOME WORK:
1) Draw a neat labeled diagram of bacteria structure.
2) Write a brief note on nutrition, growth and reproduction of bacteria.
1) a) Vibrios.
b) Bacilli.
c) Microorganisms
2) a) Nuclear or hereditary. c) Cyst.
b) 0.2-100 microns. d) 25⁰C-40⁰C