Board Paper of Class 12-Science 2006 Biology Delhi(SET 1) - Solutions
(i) All questions are compulsory.
(ii) This question paper consists of four sections A, B, C and D.
Section A contains 5 questions of one mark each.
Section B is of 10 questions of two marks each.
Section C is of 10 questions of three marks each and
Section D is of 3 questions of five marks each.
(iii) There is no overall choice. However, an internal choice has been provided.
(iv) Wherever necessary, the diagrams drawn should be neat and properly labelled.
- Question 1
What prevents collapsing of our trachea during breathing?VIEW SOLUTION
- Question 2
What advantage does the sea anemone get in the sea anemone−hermit crab facultative mutualism? Give an alternative term for this kind of mutualism.VIEW SOLUTION
- Question 3
Name the nitrogenous waste excreted in the larval and adult stages of frog respectively.VIEW SOLUTION
- Question 4
In a wheat field, some broad-leaved weeds were found by a farmer. Which phytohormone can be used to eradicate them?VIEW SOLUTION
- Question 5
Correct the statement given below with respect to brazzein: “Brazzein is a high calorie carbohydrate.”VIEW SOLUTION
- Question 6
What is reverse osmosis? Give its one application.VIEW SOLUTION
- Question 7
Which two heart sounds are heard through the stethoscope when placed on the chest? When are these sounds produced respectively?VIEW SOLUTION
- Question 8
How is polyspermy prevented in humans?VIEW SOLUTION
- Question 9
Write the full form of ELISA? Give example of the clinical application of ELISA test.
- Question 10
What is fermentation? Name any two organic compounds produced in this process.
What is glycolysis? Name the two monosaccharides which readily enter the glycolytic pathway.VIEW SOLUTION
- Question 11
Draw a diagrammatic sketch of the microscopic view of a mammalian sperm and label any four parts in it.VIEW SOLUTION
- Question 12
Name the location and function of Meibomian glands in the human eye.VIEW SOLUTION
- Question 13
What would happen to the successive trophic levels in the pyramid of energy if the rate of reproduction of phytoplanktons was slowed down? Suggest two factors which could cause such a reduction in phytoplankton reproduction.VIEW SOLUTION
- Question 14
What is cryopreservation? Give its one use.VIEW SOLUTION
- Question 15
What is meant by total fertility rate? How does it differ from replacement level?VIEW SOLUTION
- Question 16
What is agamospermy? How is agamospermy different from parthenogenesis and parthenocarpy?VIEW SOLUTION
- Question 17
How can haploid plants be raised in the laboratory? Name the plant first used in India to produce haploid plants.
Can haploid plants raise their own progeny? Give reason.VIEW SOLUTION
- Question 18
What is the law of limiting factors? How would the rate of photosynthesis be affected if the soil water becomes limiting? Explain.VIEW SOLUTION
- Question 19
Give information as asked about the following mineral nutrients in plants.
It is a constituent of __________
Its one typical deficiency symptom
The group of enzymes it activates
It is needed for the synthesis of _________
The form in which it is absorbed from the soil
Its deficiency effect on seed germinationVIEW SOLUTION
- Question 20
What is the role of calcium ions, troponin and F-Actin during contraction in striated muscles of humans?
Explain giving one example of each, the three types of joints in human skeleton, based on the capacity of movement.VIEW SOLUTION
- Question 21
A patient was complaining of frequent urination, excessive thirst, hunger, and tiredness. His fasting blood glucose level was found higher than 130 mg/dl on two occasions.
Name the disease.
Give the root cause of this disease.
Explain why the blood glucose level is higher than 130 mg/dl.VIEW SOLUTION
- Question 22
Name and explain any three adaptations of mangroves to the conditions prevailing in the Sunderbans (West Bengal)VIEW SOLUTION
- Question 23
What is eutrophication” Explain its consequences on the life of plants and animals living in such waters. Why is oxygen depletion in a eutrophicated water-body faster at night than during the day?VIEW SOLUTION
- Question 24
What is a vaccine? Give an example of a vaccine produced by recombinant DNA technology?
Name the disease against which DTP vaccination develops immunity.VIEW SOLUTION
- Question 25
Define senescence. Explain the ‘programmed senescence theory’ of ageing.VIEW SOLUTION
- Question 26
Explain the process of Crassulacean acid metabolism. How is it advantageous to plants?
Explain the major steps in Krebs cycle. Why is this cycle also called citric acid cycle?VIEW SOLUTION
- Question 27
What is electrocardiography? What is meant by P-Q interval and S -T interval in electrocardiography? Mention two medical applications of this technique.VIEW SOLUTION
- Question 28
Draw a section of the microscopic structure of human retina and label any six parts in it.
Name the structure that determines the eye colour in humans. What is the normal function of this structure?
Name the point of sharpest vision and the point of no vision in human eye.
Draw the basic structure of a neural synapse and label the following parts in it Presynaptic cell, Postsnaptic cell, Vesicles, Neurotransmitter, Receptor, Synaptic cleft.
Give any two differences between chemical synapses and electrical synapses.VIEW SOLUTION