11th zoology Chapter1

 9. Differentiate between probiotics and pathogenic bacteria

 Probiotic bacteria Pathogenic bacteria
 Beneficial Disease causing
 Converts Milk into Curd Causes Disease in plants & animals
 Eg: Vibrio cholerae (cholera) Eg: Lactobacillus

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10. Why mule is sterile in nature?


Mules are produced by mating of male donkey and female horse. Mules are sterile animals because they cannot produce gametes due to problems in pairing up of chromosomes. They have odd number of chromosomes.

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11. List any five salient features of the family Felidae


➤ They are commonly called as wild cat family. They have adaptations to detect and hunt prey.
➤ They are meat eaters (carnivores).
➤ They have cutting teeth to shear meat. Canine teeth are large and sharp.
➤ Their sizes vary from 2 kgs to 300 kgs.
➤ They have acute senses - hearing, smell, vision and touch.
➤ They have well padded toes with powerful and flexible bodies. Eg: Lion, Tigers, Cats.
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12. What is the role of Charles Darwin in relation to concept of species?



➤ Charles Darwin visited the Galapagos Islands as a naturalist on a five year voyage around South America. He found 13 types of "Mocking birds" on the same island but in different habitats.
➤ He brought back the different types and studied them. He found that only the beak pattern and usage was different in these different varieties.
➤ This made him think that adaptation to suit a particular habitat (for food) had brought about such changes in these birds which lived in different habitats.
➤ After some time they evolved into different species. The formation of new species or 'speciation' is brought about by Natural selection (Nature being the deciding factor).
➤ Hence Darwin gets this credit of attempting to explain how species evolved and role of Natural selection. The birds are referred to as Darwin's finches. In 1859 Charles Darwin in his book Origin of Species explains the evolutionary connection of species by the process of natural selection.

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13. Why elephants and other wild animals are entering into human living area?


➤ Man is destroying forests. Deforestation is increasing due to rapid urbanisation and increase in human population.
➤ When habitats are destroyed, the animals living there could not find food and shelter.
➤ They tend to wander outside of forest in search of food or shelter and enter into human living area.
➤ Decrease in availability of clean water due to pollution.
➤ The reality is that we have entered into the habitats of animals.

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14. What is the difference between a Zoo and wild life sanctuary?

Zoo:

➤ A Zoo is a place where animals are held in capitivity and Public is allowed to visit and see the animals. It is a artificially created habitat.
➤ A Zoo can sell, buy, breed or trade animals.

Wild life sanctuary:

➤ A wild life sanctuary is a large area with natural surrounding where the animals are allowed to roam freely.
➤ A boundary wall/barrier is in place to ensure that humans cannot enter the area. The animal gets the feel of a natural surrounding.
➤ In many cases sanctuaries focus on maintaining and increasing the population of a particular species. Eg: Kaziranga sanctuary in Assam focuses on Rhinoceros population

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15. Can we use recent molecular tools to identify and classify organisms?

DNA hybridization 

Molecular taxonomical tools:

Technological advancement has helped to evolve molecular taxonomical tools from classical tools to molecular tools. The accuracy and authenticity is more significant in the molecular tools.
I. The following methods are being used for taxonomical classification.

a) DNA barcoding - Uses short genetic marker in an organism's DNA to identify it as belonging to a particular species.

b) DNA hybridization- measures the degree of genetic similarity between pools of DNA sequences.

c) DNA fingerprinting - to identify an individual from a sample of DNA by looking at unique patterns in their DNA.

d) Restriction Fragment Length Polymorphisms (RFLP) analysis- difference in homologous DNA sequences that can be detected by the presence of fragments of different lengths after digestion of the DNA samples.

e) Polymerase Chain Reaction (PCR) - sequencing to amplify a specific gene, or portion of gene.

II. Neo taxonomical tools-This is based on Electron Microscopy images to study the molecular structures of cell organelles.

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16. Explain the role of Latin and Greek names in Biology.

1. Knowledge of prefixes and suffixes in biology makes it easy to understand unfamiliar words. Biology involve lot of descriptive words and it is easy to adopt names from Greek and Latin.
Many words used in Biology are derived from Greek or Latin.
Eg: 'autos' is greek word which means self.
Biological terms having 'auto' as prefix
autophagy,autotroph
Autophagy means self destruction.
Autotroph means manufacture of own food.
'bis' is a latin word which means twice.
Binary fission, Bicuspid valve are Biological terms based on this.
Meaning:
Binary fission - Divide in two
Bicuspid - Two flaps.
2. Usage of Greek and Latin words also finds universal application.

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