Questions · Page 2 of 3

1 Marks Question

Question 521 Mark
Define biogeography.
Answer
Biogeography refers to the study of distribution of living organisms in different parts of the earth.
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Question 541 Mark
In which era of geological time scale mammals dominated the scene?
Answer
Miocene epoch of Coenozoic era.
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Question 551 Mark
Complete the statement given below by filling the blank. is considered as a connecting link between the reptiles and birds.
Answer
Complete the statement given below by filling the blank. Archaeopteryx is considered as a connecting link between the reptiles and birds.
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Question 571 Mark



Study the ladder of human evolution given above and answer the following questions:
  1. Where did Australopithecines evolve?
  2. Write the scientific name of Java man.
Answer
  1. Australopithecines evolved in East African Grasslands.
  2. Homo erectus.
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Question 581 Mark
Did aquatic life fossilised? If yes, where do we come across such fossils?
Answer
Yes, the ancestors are lobefins which are living fossils.
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Question 591 Mark
Hugo de Vries gave the mutation theory. Name the plant he worked on.
Answer
Primrose plant (Oenothera lamarckiana).
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Question 651 Mark
When did bryophytes appeared on the earth?
Answer
Bryophytes were the first plant to be appeared on earth.
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Question 661 Mark
How can you suggest that biochemistry gives evidence for organic evolution?
Answer
In the same species or group of organisms, similar type of proteins are found, thus supporting organic evolution.
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Question 671 Mark
Mention the key concepts about the mechanism of biological evolution$/$ speciation according to
  1. De Vries.
  2. Darwin.
Answer
  1. De Vries: Mutation $($single step large mutation$).$
  2. Darwin: Branching descent and natural selection.
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Question 681 Mark
Name any two vertebrate's body parts that are homologous to human forelimbs (hands).
Answer
Flippers of whales and forelimbs of cheetah.
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Question 691 Mark
Why are lichens regarded as pollution indicators?
Answer
Since, they do not grow in areas that are polluted, lichens are regarded as pollution indicators.
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Question 701 Mark
Among Ramapithecus, Australopithecous and Homo habilis, who probably did not eat meat?
Answer
Homo habilis.
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Question 711 Mark
Coelacanth that was caught in 1938 in South Africa, was very significant in the evolutionary history of vertebrates. Why?
Answer
Coelacanth, a fish was caught in 1938 in South Africa, which was thought to be extinct. These were lobefins, fish-like animals with stout and strong fins, that lived both in water as well as on land. Their discovery was significant as they proved that amphibians have evolved from fish-like organisms. Lobefins are the ancestors of modern day frogs and salamanders.
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Question 721 Mark
Name the placental mammals corresponding to the Australian spotted cuscus and Tasmanian tiger cat, which have evolved as a result of convergent evolution.
Answer
Australian spotted cuscus-Lemur. Tasmanian tiger cat-Bob cat.
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Question 731 Mark
Pick out the ancestral line of cycads from the list given below-
Ferns, herbaceous lycopods, seed ferns and horsetails.
Answer
Seed ferns.
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Question 751 Mark
If the frequency of one allele is 'p' and for another, it is 'q' for one gene, what will be the formula to calculate allele frequency in future generations according to Hardy-Weinberg genetic equilibrium?
Answer
$(p+q)^2=p^2+{_2} p q+q^2=1$
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Question 761 Mark
Name the type of evolution that has resulted in the development of structures like wings of butterfly and bird. What are such structures called?
Answer
Convergent evolution. They are called analogous organs/ structures.
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Question 781 Mark
The first cellular life form originated when and where?
Answer
2000 million years ago, in aquatic environment.
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Question 851 Mark
Apart from homologous and analogous organs, which other organs can be used as evidences for organic evolution?
Answer
Vestigial organs, e.g. tail bone in human babies.
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Question 871 Mark
What is cosmozoic theory of origin of life?
Answer
According to this theory, life came from other planets or outer space in the form of units of life called spores.
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Question 881 Mark
Name any two vertebrate body parts that are homologous to human forelimbs.
Answer
Wings of birds, flippers of whales, forelimbs of dog cat, wings of bats.
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Question 901 Mark
What was the idea of early Greek thinkers about origin of life?
OR
What is Theory of Panspermia?
Answer
According to this theory (of early Greek philosophers) it was believed that units called 'Spores' or 'pansperms came on the earth along with meteorites and they must have evolved into the various life forms.
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Question 911 Mark
What is Archaeopteryx? What is its significance in evolution?
Answer
Archaeopteryx was the first flying reptile (dinosaur). It is considered as a connecting link between reptile and bird.
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Question 921 Mark
When we say "survival of the fittest", does it mean that:
  1. Those which are fit only survive, or.
  2. Those that survive are called fit.
Answer
Those individuals which survive and reproduce in their respective environment are called fit.
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Question 931 Mark
Mention the conditions on earth that favoured origin of life.
Answer
The conditions of primitive earth that favoured origin of life are:
  1. Reducing atmosphere.
  2. Very high temperature.
  3. Volcanic storms.
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Question 941 Mark
Mention brain capacities of Homo habilis and Neanderthal man.
Answer
The brain capacity of Homo habilis is 650 - 800 cc and Neanderthal man is 1400 cc.
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Question 961 Mark
Mention what caused evolution according to de Vries.
Answer
According to de-Vries, single step large mutation (saltation) caused evolution.
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Question 971 Mark
What is Big Bang theory?
Answer
Big Bang theory states that our earth originated as a result of cataclysmic evolution.
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Question 981 Mark
Name two animals that have evolved along with Tasmanian wolf in the Australian continent.
Answer
Sugar glider/ Bandicoot/ Koala/ Numbat/ Wombat/ Kangaroo/ Marsupial rat/ Marsupial mole.
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Question 1001 Mark
How do we compute the age of a rock?
Answer
Age of rock is computed by radioacarbon dating, potassium-argon dating, uranium-lead dating and rubidium-strontium dating method.
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1 Marks Question - Page 2 - Biology STD 12 Science Questions - Vidyadip