Appendix The appendix is a blind-ended tubular extension of the caecum. If it becomes blocked by hardened pieces of feaces or fruit stone, bacterial infection sets in causing inflammation and abdominal pains. In humans, the appendix is vestigial organ, i.e. It has no role to play in digestion. When it inflamed, due to infection, it is surgically r . . .
Heat is a form of energy which produces the sensation of hotness and coldness. Its unit is joule (J) and calorie (cal). Heat flows from a hot body to cold body when they are kept in contact. When heat is absorbed by a body, its temperature rises while if it loses heat energy, its temperature falls. . . .
Since heat is a form of energy, therefore the S.I. unit of heat is joule (symbol J). The other common units of heat are calorie (symbol cal) and kilocalorie (symbol kcal), where 1 kcal=1000 cal One calorie is defined as the heat energy required raising . . .
A thermometer is a device that measures temperature .A thermometer has two important elements: (1) A temperature sensor (e.g. the bulb of a mercury in-glass thermometer) in which some physical change occurs with temperature. (2) Some means of converting this physical change into a numerical value (e.g. the visible scale that i . . .
A temperature is an objective comparative measurement of hot or cold. It is measured by a thermometer. Several scales and units exist for measuring temperature, the most common being Celsius (denoted °C; formerly called centigrade), Fahrenheit (denoted °F), and Kelvin (denoted K). . . .
Thermal expansion is the tendency of matter to change in shape, area, and volume in response to a change in temperature. Temperature is a monotonic function of the average molecular kinetic energy of a substance. When a substance is heated, the kinetic energy of its molecules increases. When a substance (solid, liquid or gas) is heated , . . .
A solid has a definite shape. When a solid is heated, it expands in all the directions, hence the length, area and volume all increase on a heating a solid.The increase in length of a solid is called the linear expansion. The increase in area is called the superficial expansion and the increase in volume is called the cubical expansion . . .
The telephone and the electric wires when are connected in summer between the two poles, they are kept loose so that they may not break when they contact in winter. on the other hand , if the wires are connected in winter between the two poles, they are kept tight because they will expand in summer and will sag. The wooden wheels of a bullock-cart . . .
The heat produce mainly the following three effects: The change in temperature of the body. The change in size or shape of the body. The change in state of the body. . . .
Cornea remain alive up to 40 hours after the death of a person. If donated, the eye can be removed soon after death. It is stored in an eye bank at a very low temperature in a suitable medium such as blood plasma. For grafting, the cornea part is taken out of the eye and is fixed in a place of the defective cornea and the vision is restored. . . .
Like solid, liquid also usually expands liquid on heating. Liquids expand much more than the solid when heated. Liquids do not have a definite shape, but they have a definite volume, therefore liquids have only the cubical expansion. . . .
Gases also expand when they are heated. Gases expand much more than the liquids and the solids. Like liquids, the gases do not have a definite shape, so they also have only the cubical expansion. . . .
Fruits and vegetables have different colours because of chromoplasts. These are variously coloured plastids – yellow, orange and red. They are mostly present in petals of flowers and fruits, associated with xanthophyll (yellow) and carotene (orange red). Some colouring pigments such as blue, violet and purple are not associated with p . . .
Q. Describe human nerve cell. What function do nerve cells perform? Answer: Human nerve cell, also known as neuron, are branched like structure. A typical neuron possesses a cell body (often called the soma), dendrites, and an axon. Dendrites are thin structures that gives rise to a complex "dendritic tree". An axon is a special cellular . . .