Board Paper of Class 12-Science 2004 Biology (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
How is haemoglobin differently located in humans and earthworms?VIEW SOLUTION
- Question 2
What is apoptosis with reference to ageing?VIEW SOLUTION
- Question 3
What are the starting points of a grazing food chain and a detritus food chain respectively?VIEW SOLUTION
- Question 4
A cardiologist observed an enlarged QR wave in the ECG of a patient. What does it indicate?VIEW SOLUTION
- Question 5
Name the type of cells that produce antibodies.VIEW SOLUTION
- Question 6
What is meant by Respiration Quotient (RQ)? When will the value of RQ be l and when will it be less than1?VIEW SOLUTION
- Question 7
Explain any two functions of cerebrospinal fluid in humans.VIEW SOLUTION
- Question 8
Name the organism that causes Anthrax in cattle. Why does the infected animal die within 2 or 3 days?VIEW SOLUTION
- Question 9
Differentiate between quiescence and dormancy with reference to seed germination.VIEW SOLUTION
- Question 10
How is our gut lining protected from its own secretion of proteases?VIEW SOLUTION
- Question 11
Name the respective mineral nutrient element that
(i) forms the core constituent of the ring structure of chlorophyll
(ii) activates carboxylases
(iii) forms the component of nitrogenase
(iv) synthesises the middle lamella of plant cellsVIEW SOLUTION
- Question 12
What is photochemical smog composed of? How does this affect the plants?VIEW SOLUTION
- Question 13
Define a portal vein. Explain the functions of such a vein in our digestive system.
What is the role of calcium ions in muscle contraction?VIEW SOLUTION
- Question 14
Why is aqueous gel applied between the skin and the scan head in sonography during clinical examination? Why is this technique generally preferred to radiography?VIEW SOLUTION
- Question 15
Lichen is considered a good example of obligate mutualism. Explain.VIEW SOLUTION
- Question 16
Name the T3 and T4 components of the thyroid hormone. Explain their specific action.VIEW SOLUTION
- Question 17
Give a schematic representation of nitrogen cycle of a terrestrial ecosystem. Name any two microorganisms involved in it.VIEW SOLUTION
- Question 18
Why does the rate of photosynthesis decrease at higher light intensities? What plays a protective role in such situations?VIEW SOLUTION
- Question 19
Due to some physiological reasons the blood glucose level of an otherwise normal person has shot up above normal. How will this condition be returned to normal through hormone action?VIEW SOLUTION
- Question 20
(i) Give the scientific name of the soil bacterium which produces crystal (Cry) proteins.
(ii) How are these proteins useful in agriculture?
(iii) What do the differently written terms “Cry” and “cry” represent respectively?VIEW SOLUTION
- Question 21
Draw a labelled diagram to show the impulse conductive system in human heart.
Draw a labelled sketch of human urinary system with its associated blood vessels.VIEW SOLUTION
- Question 22
List the three prominent theories to explain water translocation in trees. Describe the most accepted theory out of these.VIEW SOLUTION
- Question 23
How is an allopolyploid produced’? Explain with an example.VIEW SOLUTION
- Question 24
Differentiate between in situ and ex situ approaches of conserving biodiversity.VIEW SOLUTION
- Question 25
Trace the development of a mature ovule from a megaspore mother cell.VIEW SOLUTION
- Question 26
Where does glycolysis occur in a cell? Explain its different steps.
Explain non-cyclic photophosphorylation in plants. Why is this process called so?VIEW SOLUTION
- Question 27
Describe oogenesis in human female. What promotes completion of second meiotic division in oogenesis?VIEW SOLUTION
- Question 28
Differentiate between inbred line and a hybrid variety of crop. Explain the steps involved in the production of the hybrid variety.VIEW SOLUTION