EVOLUTION
2013 MARCH
1. Arrange the following examples under two heads viz- homologous organs and analogous organs. (Score: 2)
Forelimb of whale and bat
Wings of butterfly and bat
Heart of man and cheetah
Eyes of octopus and mammals
2. Theory of chemical evolution is a version of theory of abiogenesis. Analyze the statement. (Score: 2)
2013 SAY
1. A specific rat population was controlled for about a decade by a poison. After a population decline for about 10 years, the rat population was increased and stabilized.
Resistance to poison is governed by a dominant autosomal gene ‘R’. in 1975 majority of the resistant animals are heterozygous at this locus (Rr).
a. What was the major genotype of the rat population before 1961? (Score: 1)
A) RR B) Rr
C) rr D) R is absent as it is produced by a mutation.
b. What explanation you give for the development of resistance against the poison in these rats? (1)
c. “This illustration can be utilized to explain the Theory of Evolution.” Substantiate. (1)
2. The diagram shows how the number of species in different groups of vertebrates has changed between 400 million years ago and 5 million years ago. The wider a block the more species there are.
a. Which is the species found most at 200 million years ago? (Score: 1)
b. Birds are most closely related to which group of organism? (Score: 1)
c. What is the trend observed in the evolution of Amphibians? (Score: 1)
2014 MARCH
1. Given below is the diagrammatic representation of the operation of Natural Selection on different traits.
a. Identify the type of natural selection A, B and C with explanation of each.
b. Define Hardy-Weinberg Principle. (4 scores)
2014 SAY
1. Arrange the following in a hierarchical manner in ascending order based on the period of their evolution.
Homo erectus, Rama pithecus, Australopithecus, Homo sapiens, Neanderthal man (Score: 1)
2. (a) The diagram below shows a particular type of evolutionary process in Australian marsupials. Identify the evolutionary phenomenon and comment on. (Score: 1)
(b) Give another example for such a type of evolutionary process and explain. (Scores: 2)
2015 MARCH
1. Match the following: (Score: 2)
a. Natural selection (1) Convergent evolution
b. Inheritance of acquired characters (2) Genetic drift
c. Analogous structures (3) Charles Darwin
d. Gene flow by chance (4) Lamarckism
2.
Vv
The above shown pictures are beaks of a particular type of bird seen in an island during Darwin’s journey.
a) Identify the bird and name the island.
b) Write the significance of this process in evolution. (Score: 2)
2015 SAY
1. Four groups of organs are given below. Read them carefully and answer the questions:
A. Thorns of Bougainvillea and tendrils of Cucurbita
B. Eyes of Octopus and mammals
C. Flippers of Penguin and Dolphin
D. Forelimbs of Cheetah and man
a. Categorise the four groups of organs as homologous organs and analogous organs.
b. Based on each group of organs differentiate convergent evolution and divergent evolution.
c. Illustrate homologous and analogous organs as evidences for evolution. (Scores: 4)
OR
Observe the diagrammatic representation and answer the questions:
a. Explain the phenomenon shown in the figure.
b. How can it be considered as an evidence of evolution?
c. Write any other example for this phenomenon. Explain.
c. Write any other example for this phenomenon. Explain.