RESPIRATORY SYSTEM AND ENDOCRINE SYSTEM 2014

RESPIRATORY SYSTEM AND ENDOCRINE SYSTEM

Earth-The earth is an oblate spheroid and not a true sphere,because it is flattened at the poles and bulges out at the equator.Its circumference is 25,000 miles.

Earth in Motion-The axis of the earth is the imaginary line on which the earth rotates.

Poles-They are the end of the axis.One end is called North Pole and other the South Pole.

The Solar System-It is the name given to the group of nine major planets(Mercury,Venus,Earth,Mars,Jupiter,Saturn,Uranus,Neptune,Pluto),and their satellites,asteroids

and hundreds of meteorites which evolve around the sun.They are kept in position on account of the pull of the sun on the planets.

The Solar System originated from the huge gaseous mass called Nebulae.

The six most abundant elements in the earth's crust are:(1)Oxygen 49.85% (2)Silicon 26.03% (3)Aluminium 7.28% (4)Iron 4.12% (5)Calcium 3.18% (6)Sodium 2.33%.

Motion of the Earth:

1.Rotation of the Earth:It turns round its own axis once in 24 hours,from West to East.

2.Revolution of the Earth:It revolves around the sun in about 365 days.

The Boundaries of the Zones:

The Torrid Zone:It lies between the Tropic of Cancer and Tropic of Capricon,i.e 23 and a half degree North and South on either of Equator side.

The Frigid Zone:The coldest zone which the sun's rays are excluded entirely at least for one whole day in a year.

The Temperature Zone:It is between the Torrid and Frigid Zone 66 and a half degree North and South on either side of the Equator.

Latitude and Longitude:Lines of Latitude and Longitude are drawn on a map to locate position of the place on the surface of the earth.

The equator is an imaginary circle on the surface of the earth midway between poles.

Latitude is the angular distance measured North to South of the Equator from the plane of the Equator.

Meridian:Meridian means "Midway Line".It is the imaginary line joining North and South Poles,which when any place comes directly below the sun,it has its midday

everywhere on it.

Prime Meridian:It is the meridian which passes through Green which is place near London.It is the zero degree longitude.

Local Time:Local Time or Sun Time of the place is the time which is reckoned according to the time when the sun's altitude is the highest at that place.At this time

the shadow of a vertical rod fixed in the ground is the shortest.

Standard Time:If every place were to use its own local time that Standard Time of India is the local time of a place near Allahabad situated at 82 and a half degree E

longitude.

Delta:It is a triangular-shaped land between the distributaries of a river.

Tide:Tide is the periodic rise and fall of sea water twice in about 25 hours.

Causes of Tide:Two forces are acting on the earth:(a)the moon's attraction,(b)the centrifugal force.Although these two forces are equal and opposite to each other at

the centre of the earth yet that is not the case everywhere on the earth.Tide is caused by the difference in these two forces.

Types of Tides:Spring Tide,Neap Tide,Eclipses,Lunar Eclipses,Solar Eclipse,Currents,Contours.

Natural Regions:The Hot Belt,Savanna or Sudan Type,Desert Type,The Monsoon Type,The Mediterranean Type,Steppe Type,China Type,British Type,Siberian Type,Eastern

Type,Tundra Type.