Question
Write a short note on extinct species?

Answer

Under this category, biological species are included which were alive in the recent past but are now no longer present in their habitat and their existence has ended in other habitats also, that is, it has become extinct from the biosphere. Once extinct, specific organisms of any species can never be obtained. Man has been hunting various terrestrial, aquatic and terrestrial animals on a large scale, as a result of which many animal species have become extinct forever from the biosphere due to human activities. The IUCN Red List (2004) documents the extinction of 784 species (including 338 vertebrates, 359 invertebrates and 87 plants) in the last 500 years. The recently extinct species include Dodo of Mauritius, Quega of Africa, Thai Laysan of Australia, Steller sea cow of Russia and three sub-species of tiger in Bali; Java and Caspian. The last 20 years alone have witnessed disappearance of 27 species. Careful analysis of records that extinction across Texas are not random some groups like amphibians appear to be more vulnerable to extinction, adding to the grim scenario of extinction is the fact that more than 15500 species worldwide are facing the threat of extinction. Presently 12% of all birds species, 23% of all mammal species, 32% of all amphibian species and 31% of all gymnosperm is species in the world face the threat of extinction. The species included in this category in India are Indian crocodile, Godavan, Indian sarus, Hornbill, Marigold, Bear and Son bird etc. which have become extinct. 

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

The enzyme DNA polymerase in E.coli is a DNA dependent polymerase and also has the ability to proof-read the DNA strand being synthesised. Explain. Discuss the dual polymerase.
Mention the role of the following in E.coli cloning vector pBR 322.
  1. Selectable marker.
  2. ori.
  3. rop.
Why are biogas plants more suitable and advantageous in rural area?
What would be the molar concentration of human DNA in a human cell? Consult your teacher.
What are the consequences of population explosion?
On world population day, Rohit and his friends arranged an awareness campaign on population explosion programme in their locality. Some elderly people tried to stop the children and asked them not to talk on such things in public. The children convinced the elders about the need for the programme and on understanding their point of view, the elders also joined the campaign.
  1. Why is such awareness programme necessary?
  2. What role has the government played in controlling population explosion?
  3. When were reproductive health programmes initiated in India?
  4. What values did Rohit and his friends show on the occasion?
How are dominance, codominance and incomplete dominance patterns of inheritance different from each other?
Depending upon the chemical nature of the template (DNA or RNA) and the nature of nucleic acids synthesized from it (DNA or RNA), list the types of nucleic acid polymerases.
In an E. coli cloning vector pBR 322, state the role of the following genes:
  1. Ori gene.
  2. Antibiotic resistance gene.
  3. Rop gene.
Explain, why family planning methods are not adopted by all the people of our country.