The living world

What is Biology?

Study of living organisms.

What is the scope of Biology?

Understanding life processes, interactions, biodiversity, and evolution.

Why is Biology important?

It helps us understand biodiversity and the complexity of life.

How did early humans classify objects?

Into living and non-living.

What view did early humans follow?

Anthropocentric (human-centered) view.

Why was progress in classification limited in early times?

Due to lack of scientific knowledge.

How many known species exist on Earth?

About 1.7-1.8 million.

What is biodiversity?

Variety of living organisms on Earth.

Why is classification necessary?

To identify, name, and organize organisms systematically.

Why are scientific names needed?

Common names vary and cause confusion.

Who introduced binomial nomenclature?

Carolus Linnaeus

What is binomial nomenclature?

A system using two words: Genus + Species.

What are the two parts of a scientific name?

Genus and Species.

How are scientific names printed?

In italics.

How are scientific names written by hand?

Underlined separately.

How does the genus name begin?

With a capital letter.

How does the species name begin?

With a small letter.

Scientific names are usually which language?

Latin or Latinized.

What does ICBN stand for?

International Code for Botanical Nomenclature.

What does ICZN stand for?

International Code for Zoological Nomenclature.

Scientific name of Lion

Panthera leo.

Scientific name of Tiger

Panthera tigris.

Scientific name of Human

Homo sapiens.

Scientific name of Mango

Mangifera indica.

Scientific name of Brinjal

Solanum melongena.

Scientific name of Housefly

Musca domestica.

Scientific name of Potato

Solanum tuberosum.

Scientific name of Wheat

Triticum aestivum.

What is taxonomy?

Science of identification, nomenclature, and classification.

Who is the Father of Taxonomy?

Carolus Linnaeus

What is characterization?

Study of features such as morphology, anatomy, and physiology.

What is identification?

Finding the correct name and group of an organism.

What is nomenclature?

Providing a scientific name.

What is classification?

Grouping organisms into categories.

Highest taxonomic category

Kingdom.

Lowest taxonomic category

Species.

Taxonomic hierarchy order

Kingdom → Phylum/Division → Class → Order → Family → Genus → Species.

What happens to similarities from species to kingdom?

Similarities decrease.

What happens to similarities from kingdom to species?

Similarities increase.

What is a species?

Organisms that can interbreed and produce offspring.

Example of species

Homo sapiens.

What is a genus?

Group of related species.

Example of genus

Panthera.

Which animals belong to Panthera?

Lion, Tiger, Leopard.

What is a family?

Group of related genera.

Example of family

Felidae.

What is an order?

Group of related families.

Example of order

Carnivora.

What is a class?

Group of related orders.

Example of class

Mammalia.

What is phylum used for?

Animals.

Example of phylum

Chordata.

What is division used for?

Plants.

Example of division

Angiospermae.

Why is classification important?

Helps understand diversity and relationships.

How is classification useful in agriculture?

Helps identify and manage organisms.

Modern classification is based on what?

Evolutionary relationships.

Biological Classification Systems

Who is the Father of Biology?

Aristotle

Who is the Father of Zoology?

Aristotle

How did Aristotle classify organisms?

Habitat and presence/absence of blood.

Who proposed the Two-Kingdom Classification?

Carolus Linnaeus

What are the two kingdoms?

Plantae and Animalia.

Main drawback of Two-Kingdom Classification

No distinction between prokaryotes and eukaryotes.

Another drawback Two-Kingdom Classification

No distinction between unicellular and multicellular organisms.

Another drawback Two-Kingdom Classification

No distinction between autotrophs and heterotrophs.

Why was fungi placement incorrect?

Fungi are heterotrophic.

Why don't viruses fit properly?

They are acellular.

Why don't lichens fit properly?

They have mixed characteristics.

Who proposed Five-Kingdom Classification?

R. H. Whittaker

When was Five-Kingdom Classification proposed?

1969.

Five kingdoms

Monera, Protista, Fungi, Plantae, Animalia.

Criteria used by Whittaker

Cell structure, body organization, nutrition, reproduction, phylogeny.

Which organisms belong to Monera?

Prokaryotes.

Who are the sole members of Monera?

Bacteria.

What does ubiquitous mean?

Present everywhere.

Shape of Coccus bacteria

Spherical.

Shape of Bacillus bacteria

Rod-shaped.

Shape of Vibrio bacteria

Comma-shaped.

Shape of Spirillum bacteria

Spiral-shaped.

What are Archaebacteria?

Ancient bacteria living in extreme environments.

What are halophiles?

Salt-loving archaebacteria.

What are thermoacidophiles?

Heat- and acid-loving archaebacteria.

What are methanogens?

Archaebacteria found in marshes producing methane.

What are Eubacteria?

True bacteria.

What are cyanobacteria?

Photosynthetic blue-green algae.

Examples of cyanobacteria

Nostoc and Anabaena.

What is chlorophyll present in cyanobacteria?

Chlorophyll a.

What type of photosynthesis occurs in cyanobacteria?

Oxygenic photosynthesis.

What are heterocysts?

Nitrogen-fixing specialized cells.

What is Mycoplasma?

Smallest living organism lacking a cell wall.

What does PPLO stand for?

Pleuro Pneumonia Like Organism.

What type of organisms are Protista?

Unicellular eukaryotes.

Nutrition in Protista

Autotrophic or heterotrophic.

What are Chrysophytes?

Diatoms and desmids.

Cell wall of diatoms contains

Silica.

What forms diatomaceous earth?

Deposits of diatoms.

What are Dinoflagellates?

Mostly marine protists with cellulose walls.

Which dinoflagellate causes red tides?

Gonyaulax.

What are Euglenoids?

Freshwater protists with pellicle.