OBESITY
What is Obesity? Obesity is a condition whereby one takes in excess calories than the body requires. The excess calories are converted into fat and stored under the skin and… Read More »OBESITY
Biology
GROWTH
What is growth? Growth is the irreversible increase in dry mass, size and complexity of an organism brought about by the synthesis of new protoplasm. For growth to be effective,… Read More »GROWTH
GENETIC: HEREDITARY, TERMINOLOGY, MENDEL’S WORK, GENOTYPE & PRINCIPLES OF HEREDITARY
GENETIC TERMINOLOGY Genetics, the scientific study of heredity and variation in all living organisms, was termed by Dilliam Bateson in 1906. Heredity/Inheritance pertains to the passage and manifestation of traits… Read More »GENETIC: HEREDITARY, TERMINOLOGY, MENDEL’S WORK, GENOTYPE & PRINCIPLES OF HEREDITARY
MALE AND FEMALE REPRODUCTIVE STRUCTURES
REPRODUCTIVE SYSTEM Most multicellular animals and plants undergo a complex form of sexual reproduction in which especially differentiated male and female reproductive cells (gametes) unite to form a single cell,… Read More »MALE AND FEMALE REPRODUCTIVE STRUCTURES
POLLINATION
This is the transfer of mature pollen grains from the anther of one flower to the mature stigma of the same or another flower of the same plant or another… Read More »POLLINATION
CIRCULATORY SYSTEM | CLOTTING, VESSELS, ARTERY, VEIN, HEART & ORGANS
PROTECTIVE FUNCTION OF BLOOD The blood performs two basic functions in mammals and these are: (1) Transportation of various substances and (2) Protection of the body against diseases The blood… Read More »CIRCULATORY SYSTEM | CLOTTING, VESSELS, ARTERY, VEIN, HEART & ORGANS
DIGESTIVE SYSTEM | HYDRA, EARTHWORM, INSECTS, BIRD, MAN
INVERTEBRATES Feeding in Hydra Digestion in Planaria Digestion in Earthworms Digestion in insects (Grasshopper) VERTEBRATES Digestion in Birds Digestion in Rabbits FEEDING IN HYDRA Hydra feeds on small aquatic organisms… Read More »DIGESTIVE SYSTEM | HYDRA, EARTHWORM, INSECTS, BIRD, MAN
CHROMOSOMES – STRUCTURE, FUNCTIONS AND PROPERTIES
What are chromosomes? These are thread-like structures found in the nucleus. They are normally very thin and coiled and are not easily visible unless the cell is dividing. When a… Read More »CHROMOSOMES – STRUCTURE, FUNCTIONS AND PROPERTIES
SEED GERMINATION: DEFINITION, TYPES, FACTORS
SEED GERMINATION: DEFINITION, TYPES, FACTORS & PROCESS What are the types of germination? The nature of germination varies in different seeds. During germination the cotyledons may be brought above the… Read More »SEED GERMINATION: DEFINITION, TYPES, FACTORS
PRIMARY AND SECONDARY GROWTH
The region of growth in plants is found in localized areas called meristems. A meristem is a group of undifferentiated cells in plants which are capable of continuous mitotic cell division.… Read More »PRIMARY AND SECONDARY GROWTH
PLANT GROWTH & HORMONES
What is plant hornmones? Plant hormones are chemicals produced in very small amounts within the plant body, and play a very important part in regulating plant growth and development. Most… Read More »PLANT GROWTH & HORMONES
Animal Growth and Development
In higher animals, most cells with the exception of the nerve cells retain their power of division. Thus, there is a continued breakdown and replacement of cells. Animal cells undergo… Read More »Animal Growth and Development
GENETICS
What is genetics? Genetics is the study of inheritance. The fact that the offspring of any species resemble the parents indicates that the characters in the parents are passed on… Read More »GENETICS
VARIATION IN POPULATION
Population is a group of organisms of the same specie living in a specified area within a given period of time. Variation refers to the differences which exist between individuals… Read More »VARIATION IN POPULATION
STRUCTURE OF DNA
What is structure of DNA? The structure of DNA was first explained in 1953 by Watson and Crick. DNA was shown to be a double helix that coils around itself.… Read More »STRUCTURE OF DNA
COMPLETE AND INCOMPLETE DOMINANCE
Complete Dominance Mendel happened to choose characters that showed complete dominance, the dominant trait completely masked the recessive one in the F1 generation. In man, certain characters are inherited in… Read More »COMPLETE AND INCOMPLETE DOMINANCE
LINKAGE
LINKAGE.
The term linkage describes the situation where genes or certain characters are located on the same chromosome.
Offspring produced by sexual reproduction show only the parental characteristics and only sometimes few new recombinants.
e. offspring with combinations of characteristics not found in either of the parents due to crossing over in first prophase of meiosis.
Genes are said to be linked when they are located close together on the same chromosome such that they are always inherited together.
MUTATIONS
What is mutations? Mutations are sudden changes in the genotype that are inherited. Mutations are rare in nature and mutated genes are usually recessive to the normal (wild type) genes.… Read More »MUTATIONS
THEORIES OF EVOLUTION
ORGANIC EVOLUTION Organic evolution is the sum total of adaptive changes from pre–existing or old forms that has taken place over a long time resulting in diversity of forms, structures… Read More »THEORIES OF EVOLUTION
GENETIC ENGINEERING
This is a technology that involves the manipulation of the genotype of an organism to get the desired trait. It also involves the transfer of gene coding for the desired… Read More »GENETIC ENGINEERING