BIOLOGY

Hours Time:2:45 Max. Marks: 70

1. This question paper consists of four sections- A, B, C and D. Section A contains 8 questions of 1 mark each. Section B is of 10 questions of 2 marks each. Section C is of 10 questions of 3 marks each and Section D is of 3 questions of 5 marks each.
2. All questions are compulsory
3. There is no overall choice. However, an internal choice has been provided in one question of 2 marks, one question of 3 marks and two questions of 5 marks weightage. Attempt only one of the choices in such questions.
4. Question no 1-5 are to be answered in one word and one sentence each.
5. Question no. 6-15 are to be answered in approx 20-30 words.
6. Questions no. 16-25 are to be answered in 30-50 words each.
7. Questions no. 26-28 are to be answered in approx 80-120 words.

Section – A

1. Some organisms share same community or habitat. Identify the type of ecosystem diversity.
2. What is apomixes?
3. Why are proteases generally released in inactive form?
4. A plant cell when kept in a certain solution got plasmolysed what was the nature of the solution.
5. Why the term SCP is misleading one?

Section – B

1. Explain that pathway which requires 3 plant organelles to complete.
2. Name the elements, whose deficiency causes

i. Grey spots on leaves.

ii. Necrosis of tip of young leaves.

iii. Absence of root nodules in leguminens plants.

iv. Plastid disintegration.

1. Given two solutions A & B, (separated by a semi permeable membrane) have Osmotic pressure 10 & 6 units respectively, while the turgor pressure in both the cases is equal & constant. Now write giving reason(s), the direction of flow of the solvent.
2. Which part of Limbic fork (system) roughly resembles the ‘sea horse’? Write its 2 functions.
3. Explain the term Sciophytes & Heliophytes.
4. Explain the role of factors controlling regeneration of limb in Newt

Or

Draw a labeled diagram of L.S. of anatropous ovule.

1. ‘Soil is exhaustible resourses’. Justify.
2. Define Parthenogenesis. Give one example of parthenogenesis from Plants & one from animals.
3. “Vaccination provides artificial active immunity while ready-made antibodies like anti diphtheria injection artificial passive immunity.” Justify.
4. Soyabean and Taichung Native I are recently introduced crops. What is such a practice called as? Name the weed that came to India through this practice. How does the government avoid weeds and pathogens from entering the country?

Section – C

1. Explain the mechanism of C₃ cycle in plants. Name discoverer of C₃ cycle.
2. Describe the molecular mechanism of water-soluble hormones action.
3. Differentiate between Red & white muscles. Write the Role of Ca²⁺ during muscle contraction.
4. What do you mean by osmoconformer. Write the only vertebrate osmoconformer. Write the process of solute water regulation in elasmobranch fishes.
5. Describe with labeled sketches the process of formation of embryo sac in plants.
6. Describe the physico chemical changes that occur during fertilization in human beings.

Or

Pertaining to the process of ageing, mention three major steps how the free radicals in the body lead to progressive decline in the functioning of cells.

1. In a habitat, it was found that a weak or tasteful organism (A) tried to imitate or resemble a strong & distasteful organism (B) to save itself from the enemies. Identify & mention the ecological phenomenon with types, exhibited by ‘A’ for adaptation. What eco-technical word you will use for ‘A’ & ‘B’.
2. Explain the Nitrogen Cycle.
3. The immune system of a person is not making discrimination between the molecules of self and non-self. How will this situation affect his body? Name any one pathological disorder, Which results due to this situation. What happens to nerve cells in multiple sclerosis?
4. What is ELISA? Write the process of ELISA to detect HIV (AIDS).

Section – D

26. Describe the cohesion tension theory to explain the mechanism of Ascent of sap in plants. How far you accept this theory? Give reasons supporting your answer.

Or

Define Transpiration. Why it is considered as necessary evil? How does it differ from Guttation?

27. Describe the structure of ear & its role as a statoacoustic organ.

28. Explain the working of ECG. Label the various parts of the waves. What are the diagnostic uses of ECG. How the waves will change during myocardial infarction and arteriosclerotic heart disease

Or

Explain the process of transmission of Nerve Impulse through the non-myelinated nerve. How does it differ in myelinated nerve?