Samacheer Class 11 Bio Zoology - The Living World

The ecosystem is defined as a community of living organisms (plants and animals), non-living things (minerals, climate, soil, sunlight, and water), and their interrelationships, e.g. Forest and grassland.

The basic need for classification are:
* To identify and differentiate closely related species.
* To know the variation among the species.
* To understand the evolution of the species.
* To create a phylogenetic tree among the different groups.
* To conveniently study living organisms.

Many organisms were not fitting into his classification. Frogs have lungs and they are amphibians while their larva, the tadpole is aquatic and respires through gills. It is difficult to classify frogs according to his method. All flying organisms such as birds, bats, flying insects were grouped together. Ostrich, emu, and penguin are flightless birds and hence they cannot be classified by his method.

The evaluation of resemblances and differences of organisms through statistical methods followed by computer analysis to establish the numerical degree of relationship among them is known as numerical taxonomy.

Species:
* A species is a group of interbreeding populations having similar characters.
* It is the basic unit of classification e.g. Felis Domestica, genus species.
Genus:
* Genus is a group of related species.
* It is the second level in classification, e.g., Felis margarita genus species.

The system of naming the organism with two names, generic name, and specific (species) name is known as the binomial system of nomenclature, e.g. Pavo cristatus – Indian pea fowl.

The system of naming the organism with three names, generic name, specific name (species), and sub-species name is known as the trinomial system of nomenclature, e.g. Corvus splendens -Indian house crow.

* It is situated in the South-Western Part of Chennai.
* It spreads over an area of 1500 acres.
* It is one of the largest zoological parks in India.
* The Zoo houses 2553 species of both flora and fauna.
(3 marks)
III. Short Questions

The ecosystem is defined as a community of living organisms (plants and animals), non-living things (minerals, climate, soil, sunlight, and water), and their interrelationships, e.g. Forest and grassland.

• In his book ‘History of Animals,’ he classifies plants and animals into two categories.
• Based on locomotion walking, flying, swimming,
• He classifies the organisms on the basis of blood.
• He classifies the animals into two as ‘Enaima’ with blood and those without blood as’ Anaima’

* R.H. Whittaker proposed the five-kingdom classification.
* It is based on cell structure.
* Mode of nutrition.
* Mode of reproduction.
* Phylogenetic relationships.
The kingdoms are
* Monera
* Protista
* Fungi
* Plantae
* Animalia

The scientific name should be italicized in printed form and the generic name and specific name should be underlined separately if it is handwritten.
* The first alphabet of the generic name should be of uppercase.
* The specific name (species) should be in lower case letters.
* The name or abbreviated name of the scientist who first published the scientific name may be written after the specific (species) name along with the year of publication, e.g. Felis Leo Linn., 1958.
* If the specific (species) name is framed after any person’s name, the name of the species shall end with i, ii or ae. e.g. Ground – dwelling lizard Cyrtodactylus varadgiri.

ALIS: Automated Leafhopper Identification System.
DAISY: Digital Automated Identification System.
ABIS: Automatic Bee Identification System.
SPIDA: Species Identified Automatically (spiders, wasp, bee wing characters).
Draw wing: Honey bee wing identification.
(5 marks)
V. Essay Questions

Probiotics
Pathogenic bacteria
1. It converts the milk into curd (Eg.) Lactobacillus
It causes diseases in plants and animals
2. It decomposes debris.
Tomato – bacterial species
3. By the action of fermentation vinegar is produced. (Eg.) Acetobacter
Anthrax, Tuberculosis Pneumonia Tetanus,

Mule gets one set of chromosomes (32) from male parent, horse and one set of chromosomes (31) from female parent, donkey. These two sets of chromosomes do not match with each other and cannot produce gametes by meiosis. Hence mule is sterile in nature.

• For the construction of houses, dams, and factories forests are destroyed. The area surface of forests is also getting reduced.
• As the bull elephant is hunted for their tusks the cow elephant during breeding season enters in to the dwelling area of people.

The recent molecular taxonomical tools can be used to identify and classify the organism. The following molecular techniques and approaches are used in molecular tools.
* DNA barcoding – Short genetic marker in an organism’s DNA to identify whether it belongs to a particular species.
* DNA hybridization – Measures the degree of genetic similarity between pools of DNA sequences.
* DNA fingerprinting – to identify an individual from a sample of DNA by looking at unique patterns in their DNA.
* Restriction Fragment Length Polymorphism (RFLP) Analysis- the difference in homologous DNA sequences can be detected by the presence of fragments of different lengths after digestion of DNA samples.
* Polymerase chain reaction (PCR) sequencing- to amplify a specific gene or portion of a gene.

Aristotle (384 to 322 BC) was the first to classify all animals in his Historia Animalium in Latin. He classified the living organisms into plants and animals. Animals were classified as walking (terrestrial), flying (birds), and swimming (aquatic) based on their locomotion.
He classified the animals with red blood cells as Enaima and those without red blood cells as Anaima. Though his method of classification had limitations, his contribution to biology was remarkable. Theophrastus did his research on the classification of plants. He was known as the Father of Botany.
Part II
11th Bio Zoology Guide The Living World Additional Important Questions and Answers

• Aristotle’s classification system had limitations and many organisms were not fitting into his classification.
• The tadpoles of frogs are born in water and have gills but when they metamorphosed into adult frogs they have lungs and can live both in water and on land. There is no answer to this question.
• Based on locomotion birds bats and flying insects were grouped either just by observing one single characteristic feature the flying ability.
• On the contrary to the above-said example, the ostrich emu and penguin are all birds but cannot fly. He did not classify them as birds.

• This domain includes single-celled organisms the prokaryotes.
• They have the ability to grow in extreme conditions like volcano vents hot springs and polar ice caps hence are called extremophiles.
• They are capable of synthesizing their food without sunlight and oxygen by utilizing hydrogen sulphide and other chemicals from the volcanic vents.
• Some of them produced methane.
• Few live in salty environments and called Halophiles.
• Some thrive in acidic environments and are called thormoacidophiles.

• Bacterias are prokaryotic.
• They do not have a definite nucleus and do not have histones.
• They have circular DNA.
• They do not possess membrane-bound organelles except for 70s ribosomes.
• Their cell wall contains peptidoglycans.
• Many are decomposers. Some are photo-synthesizers and few cause diseases.
• There are beneficial probiotic bacteria. (Eg.) Cyanobacteria produce oxygen.

Cladistic classification takes into account ancestral characters (traits commons for the entire group) and derived characters (traits whose structure and function differ from the ancestral characters). The accumulation of derived characters resulted in the formation of new subspecies.

• The scientific name should be italicized in printed form and if handwritten it should be underlined separately.
• The generic name’s first alphabet should be in uppercase.
• The specific name should be in lower case.
• The scientific names of any two organisms are not similar.
• The name of the scientist who first publishes the scientific name may be written after the species name along with the year of publication.
• (Eg.) Lion – Felis Leo Linn. 1758 (or) Felis Leo L. 1758

The scientific name should be italicized in printed form and the generic name and specific name should be underlined separately if it is handwritten.
* The first alphabet of the generic name should be of uppercase.
* The specific name (species) should be in lower case letters.
* The name or abbreviated name of the scientist who first published the scientific name may be written after the specific (species) name along with the year of publication, e.g. Felis Leo Linn., 1958.
* If the specific (species) name is framed after any person’s name, the name of the species shall end with i, ii, or ae. e.g. Ground – dwelling lizard Cyrtodactylus varadgirii.