B.Ed Course 2010-11Anjana Jha Roll No- 20

Microorganisms ( Bacteria)Std –VIII

Table Of ContentSr. No Topic

1. Introduction to Micro-organism

2. Kingdom Monera

3. Structures of Bacterial Cell

4. Photosynthesis of Bacteria

5. Harmful & Helpful Bacteria

6. Evaluation

Micro-organismsToo small to be seen with the naked eyesAggregations or colonies can be seen without

the aid of a microscopeAre found almost anywhereAre more abundant than any other life formThey are forms on which all others depend.

THE KINGDOM OF MICROORGANISMS

Kingdom Monera (Bacteria are prokaryotes)

Pro -beforeKaryon – nucleusThe simplest forms of life are

prokaryotes.Earth’s first cells were prokaryotes.

Lots of Them!Prokaryotes are Earth’s most abundant life forms.

They can survive in many environments.

They can get energy from many different sources.

Prokaryote ReviewMostly single-celledNo nucleus or organellesCircular chromosomesCell wallsReproduce mostly asexuallyAnaerobic or aerobicHeterotrophic or autotrophic

7 major structures of Bacterial cell

CapsulesCell wall RibosomesNucleoidFlagellaPilliCytoplasm

Structure of BacteriaTwo part to bacteria structure:- Arrangement - Shape

Arrangement• Paired: Diplo• Grape like structures: Staphylo• Chains: Srepto

ShapesRod: Bacillus Spheres: coccusSpirals: spirillum

Photosynthesis of Bacteria• Bacteria can be Autotrophs or Heterotrophs

• Autotrophs:- They are either photosynthetic obtaining energy from sunlight or chemosynthetic, breaking down inorganic substances for energy.

E.g.: Cyanobacteria

Photosynthesis of Bacteria Cont…Heterotrophs:- They derive energy from

breaking down complex organic compounds in the environment. This includes saprobes, bacteria that feed on decaying material and organic wastage as those that live on parasites, absorbing nutrients from living organisms.

Harmful Bacteria

• Some bacteria cause diseases

• Animals can pass diseases to humans Communicable Disease: Disease passed from one organism to another

This can happen in several ways: • Air• Touching clothing, food, silverware, or

toothbrush• Drinking water that contains bacteria

Harmful Bacteria

Human tooth with accumulation of bacterial plaque (smooth areas) and calcified tartar (rough areas)

Helpful Bacteria

• Decomposers help recycle nutrients into the soil for other organisms to grow

• Bacteria grow in the stomach of a cow to break down grass and hay

• Most are used to make antibiotics• Some bacteria help make insulin• Used to make industrial chemicals• Some bacteria live on the roots of other plants,

converting nitrogen into a usable form.

Helpful Bacteria

E.coli in small intestines

Helpful Bacteria

• Used to treat sewage          Organic waste is consumed by the bacteria, used

as nutrients by the bacteria, and is no longer present to produce odors, sludge, pollution, or unsightly mess.

• foods like yogurt, cottage & Swiss cheese, sour cream, buttermilk are made from bacteria that grows in milk

Which Kingdom does Bacteria belong to?

1. Kingdom Protista 2. Kingdom Monera 3. Kingdom Plantae 4. Kingdom Animalia

What is the scientific name of grapes like structure found in Bacteria?

1. Diplococcus2. Streptococcus3. Stephylococcus4. Tetracoccus

Where are E.Coli found?

1. Brain2. Lung3. Small Intestines4. Large Intestines