Main concepts of life science in botany for tnpsc pdf

1.MAIN CONCEPTS OF LIFE SCIENCE

• Life science has many branches like botany, zoology etc
• Biology is a study of plants and animals
• Biology can be divided into two main branches
• Botany- study of plants
• Zoology- study of animals

• Some of the sub branches are

1. Bacteriology- study of bacteria
2. Virology- study of virus
3. Phycology- study of algae
4. Mycology- study of fungi
5. Cytology- study of cell

Important terms coined by,

• Biology- Lamarck and Treriranus
• Cell- Robert Hooke
• Protoplasm- Purkinjee
• Genetics- W.Bateson
• Vaccine- Edward Jenner

Considered as father of

• Aristotle- Father of biology and zoology
• Theoprastus- Father of botany
• Gregor Johann Mandel- Father of Genetics
• Carl Linnaeus- Father of Modern Taxonomy

Micro Organisms

• Living organisms show a great degree of diversity in their size.
• They are measured in microns and milli microns. Example: Virus, bacteria, algae, fungi and protozoan.

Virus

• Virus is a Latin word which means poison. Viruses are the smallest and simplest of all living organisms.
• The study of viruses is called Virology.
• Based on their host, viruses are classified in to five types.

Phycophage (Algal Virus)

Zoophage (Animal virus)

Mycophage (Fungal Virus)

Bacteria

• The curd contains Lacto Bacillus bacteria which helps to change the milk into curd.
• Bacteria are unicellular and microscopic, belonging to the world microbes. The study of bacteria is called Bacteriology.
• Bacteria are measured in microns. 1 micron = 1/1000 millimeter.
• Four types of bacteria are recognized based on shape. They are

1. Cocci (Spherical shaped)
2. Bacilli (Rod shaped)
3. Spirillum (Spiral or cork screw)
4. Vibrio (Comma Shaped)

• On the basis of the number and arrangement of the flagella, bacteria are classified as

1. Monotrichous (Single flagellum at one end)
2. Amphitrichous (Tuft of flagella arising at both ends)
3. Atrichous (without any flagella)
4. Lophotrichous (Tuft of flagella at one ends) –
5. Peritrichous (Flagella all around)

Algae

• Algae are a unicellular green algae. It is spherical or oval in shape.
• The cell wall may have a pectic sheath around it. There is a single large cup-shaped Chlamydomonas chloroplast
• There are narrow end of the cells which helps in locomotion.
• The study of algae is called phycology.

Fungi

• The conversion of sugar solution into alcohol and liberation of carbon dioxide is known as fermentation.
• Wine, alcohols are prepared from the molasses by the fermentation activity of the yeast. etc.
• Fungi do not ‘possess chlorophyll. Hence they are incapable of photosynthesis.
• The study of fungi is called Mycology.

Protozoa

• Protozoans are unicellular organisms.
• Protozoan’s show mainly two modes of life, free living and parasitic.
• Free living organisms inhabit fresh and salt water. Parasitic forms lives as ectoparasites or endoparasites. They cause diseases.

Use of Micro organisms in medicine agriculture, industry and daily living

Micro-organisms are used in the manufacturing of antibiotics, linen, bread, wine ,beer and other industries. Microorganisms are used to enrich the soil fertility

Name of the species

Antibiotic

Streptomyces riseus Bacillus subtils