LOCATION AND STRUCTURE OF CHROMOSOMES Chromatin granules (thread – like structures) found in the nucleus of eucaryotic cells are the precursors or raw materials of
Category: SS 3 Biology (1st, 2nd & 3rd Term)
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
ADAPTIVE COLOURATION This is the possession by an organism of a colour which enables it to catch its prey, avoid its predators or enemies, secure
COMPETITION Competition is the process by which living organisms in the habitat struggle with one another for limited essential needs in the environment. Such scarce
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
STRUCTURE OF A FRUIT A fruit is a matured fertilized ovary of a flower containing one or more seeds. Contrary to this, some plants do
DEVELOPMENT OF ZYGOTE IN FLOWERING PLANTS, GERMINATION OF SEEDS, ADAPTIVE FEATURES IN A DEVELOPING ANIMAL DEVELOPMENT OF ZYGOTE IN PLANTS Pollination is followed by fertilization
COURTSHIP BEHAVIOURS IN ANIMALS Courtship is a reproductive communication between males and females of a species that ends in sexual union. Courtship behaviours in animals
THE ORGAN OF HEARING Mammals have two ears on each side of the head. The greater part of it is enclosed in the skull for
SENSORY RECEPTORS All living organisms respond to changes in their environment (stimuli). These changes can be mechanical, electromagnetic, chemical or thermal. Though most cells in
REFLEX AND VOLUNTARY ACTIONS Actions are responses to stimuli. These actions are grouped into two: involuntary (reflex) and voluntary actions. REFLEX ACTIONS Reflex actions
THE PERIPHERAL NERVOUS SYSTEM These include the sensory system (receptor and nerves leading from all parts of the body to the CNS) and the motor
THE NERVOUS SYSTEM The nervous and hormonal systems co-ordinate various biological activities in the body of multicellular animals, the basic structural unit of nervous system
HORMONES AND ENDOCRINE GLANDS Hormones are chemical substances produced or secreted by endocrine glands (ductless glands) in response to various stimuli. Hormones are secreted into
STRUCTURE OF THE LIVER The liver is the largest organ in the body of a mammal with a weight of about 1.25kg. It is reddish
HOMEOSTASIS Homeostasis is the process by which a fairly constant internal environment is maintained in an organism. The internal environment of an organism is made