refraction of human eye

The mirage is caused by the total internal reflection of light at layers of air of different densities. In a desert, the sand is very hot during day time and a result the layer of air in contact with it gets heated up and becomes lighter. The lighter air rises up and the denser air from above comes..

Question: Define heredity. Give some common instances of inherited traits in Humans. Answer: Heredity may be defined as the transmission of characteristics through generations. Common instances of inherited traits may include, colour of skin, colour of eyes, diseases ..

How do We See Colors? - The retina of our eye is composed of light sensitive cells. Light sensitive cells are of two types namely, rods and cones. There are three types of cones., those that are stimulated by low frequencies, those stimulated by intermediate frequencies and those stimulat..

Mechanism of Vision - The eye works on the same principle as that of the camera. The light rays from the object pass through the conjuctiva, cornea, aqueous humour, lens and vitreous humour in that order. All these structures refract the light such that it falls on the retina. T..

Ray optics is also called geometrical optics as it uses the geometry of straight-line paths (rays) to explain the optical phenomena. Ray optics, infact, is the limiting case of wave optics. This means for most practical purposes, we can ignore the deviation from straight-line path as postulated..

. Thus the wings of bat are homologous to the limbs of man. Vestigeal Organs in Man Certain homologous organs have no function in some species. Such as the appendix in human beings which is non-functional and its homologous organ is functional in herbivorous animals. Such non-functional h..

It is the most widely used instrument in the field of biology. It is a device meant for magnifying biological objects that cannot be seen with the naked human eye. It has two sets of lenses - objective and ocular - that magnify an object in two steps. A compound microscope can g..

Pleiotropy - It is a phenomenon where a given gene has multiple phenotypic effects. As a result, the gene not only influences the trait which it expresses, but also influences many other traits. Such a gene is called pleiotropic gene. Pleiotropic genes generally do not have the same influence on al..

Every cell, whether it is prokaryotic or eukaryotic, is enclosed in a thin covering called cell membrane . It is also called as plasma membrane or plasma lemma . The cell membrane can only be seen through the electron microscope since its thickness is well below the resolving power of human..

The earth's atmosphere is a heterogeneous mixture of minute particles. These particles include smoke, tiny water droplets, suspended particles of dust and molecules of air. When beam of light strikes such air particles, the path of the beam becomes visible. Similarly the path of a beam of light pa..