Long Answer Typea) Give a chemical test to distinguish between saturated and unsaturated hydrocarbon.
b) Name the products formed when ethane burns in the air. Write a balanced chemical equation for the reaction showing the types of energies liberated.
c) Why is the reaction between methane and chlorine in the presence of sunlight considered a substitution reaction?
(a) Define the following terms in the context of spherical mirrors:
i) Pole
ii) Centre of curvature
iii) Principal axis
iv) Principal focus
b) Draw ray diagrams to show the principal focus of a
i) concave mirror
ii) convex mirror
c) Consider the following diagram in which M is a mirror and P is an object and Q is its magnified image formed by the mirror.
a)
The function of:
Cornea: When light enters the eye, most of the refraction occurs at the surface of cornea.
Iris: It is a dark, muscular diaphragm that controls the size of the pupil.
Crystalline lens: Helps in the finer adjustment of the focal length required to focus objects at different distances on the retina.
Ciliary muscles: The lens becomes thin when ciliary muscles are relaxed thereby, increasing its focal length. Thus, we are able to see the distant object clearly. The ciliary muscles contract, when we are viewing objects nearby, increasing the curvature of the eye lens. Therefore, the eye lens becomes thicker and focal length decreases. This makes it easier to see the nearby objects clearly.
b)
i) The objective of such organisation is to light up the life of a blind person by donating eyes. the objective statement will be, 'Enlighten the life of Blind'.
ii) The arguments are:
1. We have enjoyed our life by seeing the beauty of nature. Then why not give the same pleasure to the blind. Pass on your gift of vision to the needy and do a charitable deed.
2. Age group of a person or sex does not matter when it comes to donating eyes. If a person uses spectacles or underwent surgery for cataract, can also donate eyes. A person suffering from any kind of communicable disease cannot donate eyes.
iii) Social welfare, awareness, charitability are some of the values that is developed in a person who actively participate and contribute to such programs.
(a) Write the functions of the following parts in human female reproductive system:
(i) Ovary
(ii) Oviduct
(iii) Uterus
(b) Describe the structure and function of placenta.
What is meant by speciation? List four factors that could lead to speciation. Which of them cannot be a major factor in the speciation of a self pollinating plant species. Give reason to justify your answer.
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