GENERAL TEST QUESTIONS AND ANSWERS (PART 3)

1. Differentiate between weather and climate

• Weather is the atmospheric condition of a place over a short period (days, weeks, hours, and month) but climate is the average condition of a place over a long period of time (35 years).
• Weather changes very often, but climate does not change very often.
• Weather cannot be generalized but climate can be generalized.
• Weather describes the atmospheric condition of a small area, while climate describes the atmospheric condition of large area.

 

2. Outline the characteristics of Sedimentary Rocks

• Sedimentary rocks are stratified/show distinct layers or strata.
• Sedimentary rocks may be coarse or fine grained depending on the nature of materials deposited.
• They are non-crystalline.
• They are fossilized rocks/they contain fossils of plants and animals.
• They are usually soft.
• Not resistant to erosion.
• They are permeable e.g. sandstone, coal, limestone etc.

 

3. Describe two ways in which Sedimentary rocks can be formed

Mechanically formed Sedimentary Rocks

• These are derived from sediments of pre-existing rocks.
• The rock debris is usually deposited by agents of erosion such as water, wind or glacier.
• The deposited materials are pressed together to become solid by the weight of overlying deposits.
• This process of solidification is called compaction or cementation.
• They may form conglomerates.

Organically formed Sedimentary Rocks

• These are formed from the remains of living organisms e.g. plants or animals.
• Remains of animals like corals or shellfish form calcareous rocks e.g. limestone, chalk etc.
• Those formed from the remains of vegetables/plants such as forest or swamps are called carbonaceous rocksg. coal, peat, lignite, oil and gas.

Chemically formed Sedimentary Rocks

• These are rocks formed from precipitation.
• From other rock solutions or certain minerals from solution of salt.
• They are often referred to as evaporates.
• They are also formed from crystallization e.g. Potash, gypsum, etc.

 

4. Describe the characteristics of any two zones of the soil profile

A – Horizon (also called top soil)

• It represents the surface layer of the soil profile.
• It contains more humus or organic matter.
• It is the zone of elluviation (where minerals are leached down the profile).
• It has maximum biological activities of plants and soil micro-organism.

B – Horizon (which is also called sub-soil)

• It is the zone of illuviation (where soils minerals are leached or washed down from A – Horizon accumulate).
• It contains lots of mineral matter.
• There is the conversion of organic matter from A – Horizon into inorganic matter.
• This zone may contain hard pan or it may be leached.

C – Horizon (also called zone of parent materials)

• It contains weathered parent rocks.
• It represents materials from which top and subsoil are formed.
• It is underlain by solid parent rocks called Bed rocks.

 

5. Explain any four ways in which lines of latitude differ from lines of longitude

• Lines of latitude are parallel to one another while lines of longitude converge at the poles.
• Lines of latitude get shorter towards the poles but lines of longitude are of the same length.
• The equator is the only line of latitude that is a great circle while any opposite pair of lines of longitude makes a great circle.
• Longitudes run from north to south while latitudes run from east to west.
• Lines of latitude are called parallels while lines of longitude are called meridians.
• The distance between two adjacent lines of latitude is constant at 111km while the distance between two adjacent lines of longitude gets smaller till it gets to zero at the poles.
• Latitude has the equator as its reference point while longitude has the Greenwich as its reference point.
• Longitude measures up to 360* while latitude measures up to 180*.

 

6. Highlight any three effects of the rotation of the earth

• Existence of day and night: As the earth rotates, only one part of the earth’s surface facing the sun receives the rays of the sun and experiences daylight (day) while the other part of the earth backing the sun’s rays will experience darkness (night).
• Deflection of wind and ocean currents: The rotation of the earth causes wind and ocean currents to be deflected to the right of the direction in which they move in the northern hemisphere.
• Apparent sunrise and sunset: During rotation of the earth, part of the earth that emerges from the darkness into the rays of the sun experiences sunrise while the part that is moving away from the sun’s rays to darkness will experience sunset.