Biology:2008:CBSE: [All India ]:Set-I
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Q1
Name any two vertebrate body parts that are homologous to human forelimbs.
Marks:1View AnswerAnswer:
Seal’s front flipper and bat’s wings.
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Q2
When and why do some animals like snail go into aestivation?
Marks:1View AnswerAnswer:
Some animals like snail and ground squirrels spend the dry-hot period in an inactive state called as aestivation to avoid heat. They spend the hot period in a torpid state in their burrows.
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Q3
What is the economic value of Spirulina?
Marks:1View AnswerAnswer:
Spirulina serves as food rich in protein, mineral and vitamins.
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Q4
What was the specialty of the milk produce by the transgenic cow Rosie?
Marks:1View AnswerAnswer:
Transgenic cow Rosie produces milk containing human proteins, (lactalbumen) which may help in the treatment of human emphysema.
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Q5
How do neutrophils acts as a cellular barrier to pathogens inhuman?
Marks:1View AnswerAnswer:
The neutrophils are an important part of phagocytic barrier of innate immunity. They perform the process of phagocytosis by engulfing the microbes, virus, cellular debris etc.
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Q6
Mention the polarity of the DNA strand a-b and c-d shown in the replicating forks given below
Marks:1View AnswerAnswer:
a-b has 3’-->5’ and c-d has 5’-->3’.
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Q7
Mention any two significant roles predation plays in nature.
Marks:1View AnswerAnswer:
(i) Predation keeps check on the prey population.
(ii) Predators act as conduits for energy transfers across trophic levels . -
Q8
Why is the polar region not a suitable habitat for tiny humming birds?
Marks:1View AnswerAnswer:
According to the Bergman’s rule warm–blooded animals (birds and mammals) are generally of large size in colder region. Moreover humming birds do not have any anti-freezing protein in their blood like fishes, essential for living in low temperature (below 00C).
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Q9
(a) Expand IUD.
(b) Why hormone releasing IUD considering a good contraceptive to space children?Marks:2View AnswerAnswer:
(a) IUD: Intra Uterine Devices.
(b) The hormone releasing IUDs, make the uterus unsuitable for implantation and the cervix hostile to the sperm. So IUD is a good contraceptive for females to space children. -
Q10
Name the interaction in each of the following:
(a) Cuscuta growing on a shoe flower plant
(b) Mycorrhizae living on the roots of the higher plants
(c) Clown fish living among the tentacle of sea anemon
(d) Koel laying her eggs in crow’s nestMarks:2View AnswerAnswer:
(a) Parasitism
(b) Mutualism
(c) Commensalism
(d) Commensalism
