1) Evidence from comparative anatomy Homologous structures can be used to explain the evidence of comparative anatomy....
Month: February 2023
A) Mutation theory of organic evolution Mutation is a change in genetic material resulting in a new...
Charles Darwin, a British biologist, in 1859 propounded a theory of organic evolution by Natural Selection leading...
Jean Baptiste Lamarck, a French biologist was one of the first biologists to put forward the theory...
The world is occupied by millions of different kinds of plants and animals. These plants and animals...
The lower plants All the plants from the single-celled Chlamydomonas, bacterium, Phacus to the simple multicellular Spirogyra,...
Physical Setting The coastal lowlands bordering of Nigeria range in height from sea level to 150m above...
Physical Setting The western highlands region covers Oyo, Osun, Ondo, Ekiti, Edo and parts of Kwara and...
Physical Setting The Cross River plains lie between the Udi hills to the west and highlands of...
Physical Features The Niger-Benue trough is a massive depression in the middle of the country, which is...
Physical Features The Chad Basin in the north eastern extreme corner of Nigeria is basically a flat...
Physical Features The Sokoto plain in northwest Nigeria is essentially a dissected lowland, about 300metres above sea...
This region is found east of the Niger delta and south of River Benue. It is bordered...
Physical Setting The eastern highlands consist of chains of hills, plateaus and mountains along the eastern borderlands...
Nigeria can be classified into nine broad geographical regions, each having obvious and essentially similar physical settings,...
Physical Features This is a very extensive region that extends from Katsina in the north to Yelwa...
The part of plasma which filters into the spaces among the tissues and flows in vessels similar...
There are three plans or types of blood circulation in human beings, other mammals and birds. They...
The heart is an muscular organ that pumps blood to all human parts of the body. It...
The main physical features are the geology, relief and drainage systems. They are examined generally and on...
Nigeria is blessed with abundant mineral resources; and they are found all over the country. The major...
The transport system carries food and oxygen to all tissues and removes waste materials of metabolism, convenes...
The group – Pteridophyta consists of ferns and club-mosses. Dryopteris is a fern. It is seen growing...
Mosses are small, green and simple land plants belonging to phylum Bryophyta and class Musci. They are...
Seeds A seed is a structure which develops from the ovule after fertilization. A seed consists of...
After the maturation of fruits, an abscission layer is formed at the point of attachment of the...
Swimming movements Each side of the vertebral column (flexible backbone) of a fish is made of muscle...
The appendicular skeleton is made up of the limb girdles (pectoral and pelvic girdles) and the limbs...
There are over 2,000,000 known different organisms in the world today and probably over 1,000,000 are left...
The animal kingdom is divided into invertebrates (animals without backbones) and vertebrates (animals with backbones). Invertebrates...
The modern classification system based on physiology, biochemistry and embryology have revealed distinct similarities between living organisms...
Cockroach is an omnivorous animal eating anything ranging from starchy and sweet things to papers, clothes etc....
Movements in Hydra 1) Swaying Sometimes Hydra comes to rest on rock or other suitable hard surface...
Haemorrhage (bleeding) is the coming out of blood from the blood vessels which have been damaged. When...
Pollination is defined as the transfer of mature pollen grains from the anthers of one flower to...
Immediately after pollination, fertilization follows. Fertilization is the union of male and female gametes to form a...
This is the part of the plant which grows above the soil except the modified aerial roots....
The root system is the part of the plant growing in the soil. This excludes the underground...
The flowering plants form a group of plants known as Angiosperms. They are characterized by the possession...
Primates are the most highly developed of all mammals with large brain, forward-facing eyes with bilocular vision,...
The mammalian gametes are male gametes called sperm or spermatozoa (singular = spermato-zoon), while the female gametes...
Germination is a process by which the embryo of a seed grows out of its testa and...
The physical setting of Africa is defined by its relief, drainage, climate and vegetation, among others. These...
Parturition (labour) is the expulsion of the foetus, placenta and foetal membranes from the uterus. After about...
When the embryo has been implanted, it produces four extraembryonic membranes (membranes outside the body of the...
Industrial enterprise in Nigeria can be broadly classified into (i) local arts and craft, and (ii) modern...
It is possible to identify specific relief features on topographical maps by examining the way their contour...
The liver is the largest gland in the body. It is dark-red, spongy and lobed. The lobes...
The stomach is a thick-walled large muscular sac which lies in the left portion of the abdominal...
Experiment 1 Aim: To demostrate the action of ptyalin (saliva) on cooked starch. Method: Some saliva is...
