Series OSS Code No. 137
OPHTHALMIC TECHNIQUES (Vocational)
BIOLOGY (Theory) Paper I
Time allowed : 3 hours Maximum Marks : 30
(i) Attempt any ten questions.
(ii) All questions carry equal marks.
1. (a) List the parts of a compound microscope in sequence starting from the mirror up to your eyes, through which the light travels while you are examining a slide under it.
(b) How does an electron microscope differ from a compound microscope in regard to
(i) the nature of objective lens, and
(ii) the source of illumination ? 3
2. (a) List the three major points of the cell theory.
(b) Which one of the following does not match with the category of the organic compounds of the remaining three, and why ?
Lipase, Maltase, Pepsin, Insulin 3
3. Given below is a diagrammatic sketch of one of the stages of mitotic type of cell division.
(i) Is it a plant cell or an animal cell ? Give one reason in support of your answer.
(ii) Name the stage that preceded it and draw a diagram of how it may have looked like. 3
4. Taking the example of flower colour in garden pea, explain the terms allele, dominant and heterozygous.
5. (a) Explain the term ‘variation’ with respect to the following features in humans : Height, Ability to roll tongue and ABO blood groups.
(b) Differentiate between continuous and discontinuous variations with respect to the same three features mentioned above in (a). 3
6. Write briefly about the following in humans as asked against each : 3
(i) Autosomes - meaning and their total number,
(ii) Sex-linked characters - any two examples
(iii) Polygenic inheritance - definition and one example
7. Draw a labelled diagram of the general structure of a human sperm as observed through electron microscope. 3
8. Explain briefly the term alternation of generations as found in angiosperms. 3
9. Write about the following diseases as asked against each : 3
(i) Typhoid : mode of transmission and any one main symptom
(ii) Rabies : category of pathogen and mode of transmission
(iii) Ringworm : category of pathogen and the body part affected
10. (i) Define disease.
(ii) Mention any one difference between infectious diseases and non-infectious diseases.
(iii) How do mosquitoes and houseflies differ in their mode of spreading diseases ? 3
11. (i) What is a forest ?
(ii) List any four ways how forests are advantageous to us. 3
12. Name the micro-organism which the bakers use in making bread, and briefly describe the steps and the process involved.