POPULATION CHARACTERISTICS
1) Size In studying the population in any country, the first consideration is to determine the size of the population or the total number of people in the country. This is usually done by...
Monthly Archive: February 2023
POPULATION AND DEVELOPMENT
Population is important both as a factor and as a measure of development in a country. The term, population, is used to embrace the sum total of the human resources available in a given...
POPULATION SIZE AND DENSITY OF AFRICA
The availability of reliable population data is one of the major problems of development planning in Africa. Most African countries at independence had not taken a complete census of their population and, therefore, had...
FUNCTIONS OF SETTLEMENTS
All settlements perform certain useful functions to justify their continued existence. Most of them have several functions. A village may just serve the community as a meeting place for people and goods and have...
LOCATION OF SETTLEMENTS
A close look at the towns and cities shown in your atlas will reveal that they have certain advantages of site and position which have enabled them to grow. The site of a town...
RURAL VERSUS URBAN SETTLEMENTS
Rural and urban settlements may be distinguished from one another on the basis of populations size and function. Rural settlements are relatively small settlements whose populations are no more than a few hundreds or...
EVIDENCES IN SUPPORT OF ORGANIC EVOLUTION
1) Evidence from comparative anatomy Homologous structures can be used to explain the evidence of comparative anatomy. Homologous structures are those structures which are built in the same common plan but yet modified to...
EVOLUTION OF NEW SPECIES BY MUTATION AND ISOLATION
A) Mutation theory of organic evolution Mutation is a change in genetic material resulting in a new stable characteristic which can be inherited by offspring. Hugo De Vries, a Dutch botanist propounded the mutation...
DARWIN’S THEORY AND MODERN THEORIES OF ORGANIC EVOLUTION
Charles Darwin, a British biologist, in 1859 propounded a theory of organic evolution by Natural Selection leading to the origin of species. His theory of natural selection is as follows: 1) Overproduction: All living...
LAMARCK’S THEORY OF ORGANIC EVOLUTION
Jean Baptiste Lamarck, a French biologist was one of the first biologists to put forward the theory of organic evolution in 1801. His idea of organic evolution was hinged on three theories. 1) The...
DIVINE CREATION AND ORGANIC EVOLUTION
The world is occupied by millions of different kinds of plants and animals. These plants and animals are adapted to different kinds of habitats and niches. How did these different organisms come to exist...
MECHANISM OF TRANSPORTATION IN PLANTS
The lower plants All the plants from the single-celled Chlamydomonas, bacterium, Phacus to the simple multicellular Spirogyra, Funaria (Bryophyta) that lack conducting vessels use their cytoplasm for the movement and distribution of materials. Most...
SOUTHERN COASTLANDS OF NIGERIA
Physical Setting The coastal lowlands bordering of Nigeria range in height from sea level to 150m above sea level and extend across the entire length of the country coast from Yewa-Badagry area in the...
SOUTH WESTERN HIGHLANDS OF NIGERIA
Physical Setting The western highlands region covers Oyo, Osun, Ondo, Ekiti, Edo and parts of Kwara and Kogi States. The highlands generally range between 300m and 700m above sea level. There are isolated local...
CROSS RIVER PLAINS
Physical Setting The Cross River plains lie between the Udi hills to the west and highlands of the eastern borders of Nigeria. The Cross River and its tributaries dominate the drainage system of this...
NIGER BENUE TROUGH
Physical Features The Niger-Benue trough is a massive depression in the middle of the country, which is generally 300m below sea level. The trough derives its name from the two major rivers in the...
THE CHAD BASIN
Physical Features The Chad Basin in the north eastern extreme corner of Nigeria is basically a flat plain at an elevation of about 300m above sea level. Sand dunes are common in several places...
THE SOKOTO PLAIN
Physical Features The Sokoto plain in northwest Nigeria is essentially a dissected lowland, about 300metres above sea level. It is drained by two major rivers and their tributaries; these are the Sokoto and Rima...
EASTERN SCARPLANDS OF NIGERIA
This region is found east of the Niger delta and south of River Benue. It is bordered on the east by the Cross River Plains as shown in Fig. 43.2. Physical Features Major...
EASTERN HIGHLANDS OF NIGERIA
Physical Setting The eastern highlands consist of chains of hills, plateaus and mountains along the eastern borderlands of Nigeria. Prominent among these relief features are Bamenda highlands, Biu plateau, Mambila plateau, Shebshi and Alantika...
GEOGRAPHICAL REGIONS OF NIGERIA
Nigeria can be classified into nine broad geographical regions, each having obvious and essentially similar physical settings, people and population, resources and economic activities, transportation and development issues and problems. These regions are shown...
NORTH CENTRAL HIGHLANDS OF NIGERIA
Physical Features This is a very extensive region that extends from Katsina in the north to Yelwa in the West, Bauchi in the east and Kafanchan in the south. The landscape is made up...
WORLD POPULATION DISTRIBUTION
Apart from their very rapid rate of increase, human beings are also very unevenly distributed, which leads to the problem of overpopulation in some areas. Less than 20 percent of the world’s surface is...
METHODS OF SHOWINGS RELIEF ON MAP
Various methods have been devised by geographers, particularly cartographers (geographers skilled in map making), to show relief on maps. These methods, their merits and demerits are discussed below. Contour Lines These are lines drawn...
WORLD SHIPPING ROUTES
The following are some of the principal ocean trade routes. 1) The North Atlantic Route: This is the busiest and the most important route, that links two of the most populous and heavily industrialized...
DAIRY FARMING
Dairy farming is the tending of animals for the primary purpose of producing milk for sale. This milk comes mainly from cows; but in some parts of the world milk is obtained also from...
LYMPHATIC SYSTEM
The part of plasma which filters into the spaces among the tissues and flows in vessels similar to arteries and veins constitute the lymphatic system. The lymph is clear colourless tissue fluid. The vessels...
THE CIRCULATION OF BLOOD
There are three plans or types of blood circulation in human beings, other mammals and birds. They are the pulmonary circulation, systemic circulation and the coronary circulation. The pulmonary circulation (Heart ->lung ->heart)...
THE PATTERN OF WORLD POPULATION DISTRIBUTION
1) The very sparsely populated parts of the world These include the cold polar lands of the Arctic and Antarctic, the Canadian and Eurasian tundra, Greenland and the high mountains of the Himalayas, the...
URBANIZATION AND ITS PROBLEMS
The growth of towns in human numbers leads directly to the area expansion of the town limits. The surrounding agricultural land is gradually taken over by urban structures and factory sites. The wealthier people...
HEART
The heart is an muscular organ that pumps blood to all human parts of the body. It lies at the centre of the thoracic cavity in the pericardial cavity and being flanked on either...
PHYSICAL SETTING OF NIGERIA
The main physical features are the geology, relief and drainage systems. They are examined generally and on regional basis. Geology The geology of Nigeria shows that the rocks found in the country range...
DISTRIBUTION OF NIGERIA’S MINERAL AND POWER RESOURCES
Nigeria is blessed with abundant mineral resources; and they are found all over the country. The major minerals found in sedimentary rocks include, coal, petroleum, natural gas, and limestone; and those found in basement...
TRANSPORT SYSTEM
The transport system carries food and oxygen to all tissues and removes waste materials of metabolism, convenes hormones from ductless glands to their target organs and the body temperatures are equalized. Needs for...
PLANTS AND THE ECOSYSTEM
All living things as well as the physical environment in which they live interact with one another, that is, they influence one another’s character growth and development. There is interaction between plants or animals...
VEGETATION DESCRIPTION
Vegetation is usually described by reference to its flora or floristic (species) composition and its structural characteristics. A plant community is composed of different species of plants and different plant life forms (trees, shrubs...
SUCCESSION
Vegetation is never static; it is continually changing in composition and structure. This is because the habitat factors themselves are continually changing. Furthermore, the vegetation itself also modifies its habitat and thereby generates change...
HABITAT FACTORS
The area of land or site occupied by a given plant or plant community is referred to as its habitat. The type of plant community or vegetation which occurs in any area depends partly,...
DEFINITION OF VEGETATION
Vegetation refers to the community of different kinds or species of plants growing together in an area and possessing a certain general physical appearance. This physical appearance arises from (a) the relative proportions of...
CYCLONIC ACTIVITY
Tropical Cyclones, Typhoons, Hurricanes and Tornadoes All these are different kinds of tropical cyclones. They are well-developed low-pressure systems into which violent winds blow. Typhoons occur in the China Sea; tropical cyclones in the...
FOHN WIND OR CHINOOK WIND
Both the Fohn and Chinook winds are dry winds experienced on the leeward side of mountains when descending air becomes compressed with increased pressure. The Fohn wind is experienced in the valleys of the...
FERN
The group – Pteridophyta consists of ferns and club-mosses. Dryopteris is a fern. It is seen growing in large number as epiphytes on oil palm trees. Dryopteris has a tuft of strong adventitious roots,...
MOSSES
Mosses are small, green and simple land plants belonging to phylum Bryophyta and class Musci. They are found growing on damp places. A common example of mosses is Funaria hygrometrica commonly found growing on...
SEEDS AND FRIUTS
Seeds A seed is a structure which develops from the ovule after fertilization. A seed consists of an embryo and one or two cotyledons. It may contain an endosperm or food reserve. The embryo...
SEASONAL CHANGES IN PRESSURE ON THE GLOBE
As the greater part of the globe experiences seasonal changes in temperature, it is to be expected that the pressure belts and their associated winds will also be affected. 1) On 21 June, the...
ATMOSPHERIC AIR PRESSURE AND WINDS
Atmospheric pressure is the most important factor influencing climate, since differences of air pressure cause air circulation or movement which in turn influence weather elements. Atmospheric pressure is the pressure or weight of the...
OTHER FORMS OF CONDENSATION
1) Snow: This is formed when water vapour condenses in the atmosphere at temperatures below freezing point. Then the water vapour condenses directly into ice crystals. A snowflake is a mass of ice crystals...
TYPES OF RAINFALL
There are three major types of rainfall. 1) Convectional rainfall: This type of rainfall is most common in regions that are intensely heated, either during the day, as in the tropics, or in the...
DISPERSAL OF FRUITS AND SEEDS
After the maturation of fruits, an abscission layer is formed at the point of attachment of the fruits to the stems. This layer later dries up and the fruits drop from the plant. Some...
MOVEMENTS IN FISH
Swimming movements Each side of the vertebral column (flexible backbone) of a fish is made of muscle blocks or myotomes. The muscle blocks are arranged in a zig-zag fashion from head to tail. Each...