Recent questions tagged cbsc

Why are the wings of butterfly and birds said to be analogous organs? Name the type of evolution, the analogous organs are a result of?

asked Apr 13, 2019 by priyanka.clay6

1 answer

Write Oparin and Haldane`s hypothesis about the origin of life on Earth. How does meteorite analysis favour this hypothesis?

asked Apr 13, 2019 by priyanka.clay6

1 answer

Convergent evolution leads to analogous structures. Explain with the help of an example.

asked Apr 13, 2019 by priyanka.clay6

1 answer

Divergent evolution leads to homologous structures. Explain with the help of an example.

asked Apr 13, 2019 by priyanka.clay6

1 answer

Categorise the following pairs of examples as convergent or divergent evolutions : a. Eyes of Octopus and mammals. b. Wings of butterfly and birds. c. Tuber of sweet potatoes and potato. d. Thorns in Bougainvillea and tendrils in Cucurbits.

asked Apr 13, 2019 by priyanka.clay6

1 answer

Name the ancestors of man based on the features given below : a. Human-like meat eater with 900 cc brain lived in Java. b. More human with brain size 1400 cc, lived in Central Asia, used hides and buried their dead. c. Human-like, vegetarian, with brain capacity between 650 cc and 800 cc. d. Man-like primate, that existed about 15 mya. Fossils found in Tanzania.

asked Apr 13, 2019 by priyanka.clay6

1 answer

How does palaeontological evidence support evolution of organisms on Earth?

asked Apr 13, 2019 by priyanka.clay6

1 answer

Write about the ancestry and evolution of bat, horse and human on the basis of a comparative study of their forelimbs. What are these limbs categorised as?

asked Apr 13, 2019 by priyanka.clay6

1 answer

List the two main propositions of Oparin and Haldane.

asked Apr 13, 2019 by priyanka.clay6

1 answer

How do Darwin's finches illustrate adaptive radiation?

asked Apr 13, 2019 by priyanka.clay6

1 answer

Mention the type of evolution that has brought the similarity as seen in potato tuber and sweet potato.

asked Apr 13, 2019 by priyanka.clay6

1 answer

Pick out the ancestral line of Angiosperms from the list give below: Conifers, Seed ferns, Cycads, Ferns.

asked Apr 13, 2019 by priyanka.clay6

1 answer

List the two characteristics of mutation that help in explaining evolution according to De Vries.

asked Apr 13, 2019 by priyanka.clay6

1 answer

What did Louis Pasteur's experiments on 'killed yeast' demonstrate? Name the theory that got disproved on the basis of his experiment.

asked Apr 13, 2019 by priyanka.clay6

1 answer

Identify the examples of convergent evolution from the following: a. Flippers of penguins and dolphins. b. Eyes of octopus and mammals c. Vertebrate brains

asked Apr 13, 2019 by priyanka.clay6

1 answer

Mention what caused evolution according to de Vries. OR What causes speciation according to Hugo de Vries?

asked Apr 13, 2019 by priyanka.clay6

1 answer

Name the placental mammals corresponding to the Australian 'spotted cuscus' and 'Tasmanian tiger cat', which have evolved as a result of convergent evolution.

asked Apr 13, 2019 by priyanka.clay6

1 answer

Why are lichens regarded as pollution indicators?

asked Apr 13, 2019 by priyanka.clay6

1 answer

Are the thorns of Bougainvillea and tendrils of Cucurbita homologous or analogous? What type of evolution has brought such a similarity in them?

asked Apr 13, 2019 by priyanka.clay6

1 answer

Study the ladder of human evolution given above and answer the following questions : a. Where did Australopithecines evolve ? b. Write the scientific name of Java man.

asked Apr 13, 2019 by priyanka.clay6

1 answer

What does Hardy-Weinberg equation $p^2 + 2pq + q^2 = 1$, convey?

asked Apr 13, 2019 by priyanka.clay6

1 answer

When does a species become founders to cause founder effect?

asked Apr 13, 2019 by priyanka.clay6

1 answer

Coelacanth was caught in 1938 in South Africa. Why is it very significant in the evolutionary history of vertebrates?

asked Apr 13, 2019 by priyanka.clay6

1 answer

Comment on the similarity between the wing of a cockroach and the wing of a bird. What do you infer from the above with reference to evolution?

asked Apr 13, 2019 by priyanka.clay6

1 answer

Write the similarity between the wing of a butterfly and the wing of a bat. What do you infer from the above with reference to evolution?

asked Apr 13, 2019 by priyanka.clay6

1 answer

Identify the examples of homologous structures from the following: a. Vertebrate hearts. b. Thorns in Bougainvillea and tendrils of Cucurbita. c. Food storage organs in sweet potato and potato.

asked Apr 13, 2019 by priyanka.clay6

1 answer

Write the formula to calculate allele frequency in future generations according to Hardy – Weinberg genetic equilibrium.

asked Apr 13, 2019 by priyanka.clay6

1 answer

Explain eutrophication.

asked Apr 13, 2019 by priyanka.clay6

1 answer

Write a note on sources of noise pollution and effect of noise pollution.

asked Apr 13, 2019 by priyanka.clay6

1 answer

Observe the following figure carefully and answer the questions that follow

asked Apr 13, 2019 by priyanka.clay6

1 answer

a)Why are catalytic convertors recommended for vehicles ? b)Why should such vehicles use only unleaded petrol. c)Why is CNG preferred to diesel as a fuel in vehicles.

asked Apr 13, 2019 by priyanka.clay6

1 answer

Enlist four harmful effects caused to the humans living in areas having polluted air. Suggest two measures to reduce air pollution.

asked Apr 13, 2019 by priyanka.clay6

1 answer

Deforestation is creating a lot of problems in the environment. List the consequences of deforestation.

asked Apr 13, 2019 by priyanka.clay6

1 answer

During the past century, lakes and ponds in many parts of the earth have been gradually converted into land. (a) What is the phenomenon called? (b) How does human activity accelerate this phenomenon ? (c) What measures can we take to control this?

asked Apr 13, 2019 by priyanka.clay6

1 answer

Explain bio magnification of DDT in an aquatic food chain. How does it affect the bird population?

asked Apr 13, 2019 by priyanka.clay6

1 answer

Integrated organic forming is a cyclical zero waste procedure. Justify.

asked Apr 13, 2019 by priyanka.clay6

1 answer

People have been actively participating in the efforts for the conservation of forests. (i) Name the award instituted in respect of Amrita Devi to promote such efforts. (ii) Name the movement launched to protect the trees by hugging them. (iii) Name the step Government of India has undertaken in 1980.s to work closely with the local communities for protecting and managing forests.

asked Apr 13, 2019 by priyanka.clay6

1 answer

Many coastal areas may get submerged due to the environmental changes taking place at the present rate. Give the cause, and state two measures to check it.

asked Apr 13, 2019 by priyanka.clay6

1 answer

Why are grains and vegetables produced in organic farms supposed to be better for human consumption than those produced in farms where chemical fertilizers, pesticides etc. has been used?

asked Apr 13, 2019 by priyanka.clay6

1 answer

What are the advantages of CNG?

asked Apr 13, 2019 by priyanka.clay6

1 answer

India in last two decades has seen a boom in automobile production and use. (a) What has been its environmental impact ? (b) What steps are being taken so that the rapid increase in the number of automobiles does not become a curse?

asked Apr 13, 2019 by priyanka.clay6

1 answer

Dumping waste in landfills is not a real solution for disposing wastes. Why?

asked Apr 13, 2019 by priyanka.clay6

1 answer

Identify the wrong pair/s and correct it. a) Chernobyl incident - Radioactive waste. b) Snow blindness cataract - High dose of CFC. c) Chipko movement - Save trees. d) Polyblend - Solves air pollution.

asked Apr 11, 2019 by priyanka.clay6

1 answer

In the above graph what does A and B depict?

asked Apr 11, 2019 by priyanka.clay6

1 answer

CFCs are widely used as refrigerants. Then why is it suggested to reduce its emission a far as possible? Explain.

asked Apr 11, 2019 by priyanka.clay6

1 answer

A farmer saw water in a pond turned green and with dead fishes. a) What is the reason for the death of fishes? b) Name the phenomenon that leads to the death of fishes.

asked Apr 11, 2019 by priyanka.clay6

1 answer

Mention the green house gases and their proportion in the pie diagram given below.

asked Apr 11, 2019 by priyanka.clay6

1 answer

A person has inhaled air having particulate pollutants of size less than 2.5 micrometers in diameter. What could be the impact of their pollutants on his respiratory system?

asked Apr 11, 2019 by priyanka.clay6

1 answer

A man had a B. class Benz which has a very good catalytic converter. On his way the petrol was exhausted and he stopped at a petrol pump. The person at the petrol pump had only leaded petrol. Out of necessity the man had to fill leaded petrol in his car. a) What is its impact on the catalytic activity of the converter ? b) Explain the impact on the environment.

asked Apr 11, 2019 by priyanka.clay6

1 answer

It was observed that some of the aquatic birds’ population has been declining. On analysis of the water in their habitat, high concentration of DDT was found. a) What caused the decline is birds’ population? b) What is this phenomenon known as?

asked Apr 11, 2019 by priyanka.clay6

1 answer

Ask Questions, Get Answers