Author: Msomi Bora

TOPIC 6: REPRODUCTION Concept of Reproduction Reproduction is the ability of living organisms to form new individuals of the same species from those already in existence. Here, the new organisms replace those that have died and so life continues. It can also be defined as the process whereby organisms produce new individuals of the same species. It is one of the important features of living things. The Merits and Demerits of Sexual and Asexual Reproduction Explain the merits and demerits of sexual and asexual reproduction Sexual Reproduction This is a type of reproduction in which new organism is produced when…

TOPIC 5: REGULATION Concept of Regulation The Concept of Regulation Explain the concept of regulation Living organisms are subjected to wide variations in temperature, light, acidity, salinity, wind speeds, availability of water minerals and nutrients. These environmental factors create a shifting external setting to which organisms must adjust or die. The central problem for a living thing is to maintain a steady state internally in the force of an often harsh and fluctuating external environment. Homeostasis is the maintaining of a constant condition of the internal environment of the body by regulatory process. OR It is the maintenance of constant…

TOPIC 4: EXCRETION Concept of Excretion The Concept of Excretion Explain the concept of excretion Chemical reactions occur in the cells of living organisms all the time to carry out the life processes. The sum of these reactions is called metabolism. Metabolism produces useful products as well as toxic (poisonous) by-products. These toxic substances have to be removed as they are harmful if allowed to accumulate. The removal of metabolic waste products from the body of an organism is known as excretion. The major excretory products are carbon dioxide, excess water, and nitrogenous compounds like ammonia, urea, uric acid, etc.…

TOPIC 3: COORDINATION Concept of Coordination. The Concept of Coordination in Organisms Explain the concept of coordination in organisms Coordination is the working together of the various organs of an organism in a systematic manner so as to produce a proper response to the stimuli. Without coordination the body becomes disorderly and it may fail to function properly. The Ways in Which Coordination is Brought About Outline the ways in which coordination is brought about The coordination in simple multicellular animals takes place through nervous systemonly. The control and coordination in higher animals called vertebrates (including humanbeings) takes place through nervous…

TOPIC 2: MOVEMENT Concept of Movement and Locomotion The Concept of Movement and Locomotion Explain the concept of movement and locomotion Movement refers to change of position and posture. Therefore the change of position of body parts such as limbs and other body parts. Locomotion is the movement or change of position of the whole organism from one place to another. But normally organisms have different kinds of movement. Plants show movement but do not show locomotion. Since…

TOPIC 1: CLASSIFICATION OF LIVING THINGS Kingdom Plantae, Division Coniferophyta (Conifers) General and Distinctive Features of the Division Coniferophyta Explain general and distinctive features of the division coniferophyta Division Coniferophyta or the conifers belong to Kingdom Plantae. These plants are gymnosperms meaning non-flowering. They are non-flowering but seed bearing plants. They have vascular tissues. They are woody plants majority being evergreen trees. Few varieties are shrubs What are the general and distinctive features of the Division Coniferophyta? General characteristics They have secondary growth whose thickening can be observed in cross section of a stem revealing annual rings. Secondary Growth is…

TOPIC 5: GASEOUS EXCHANGE AND RESPIRATION The Concept of Gaseous Exchange Organs Responsible for Gaseous Exchange in Living Organisms Identify organs responsible for gaseous exchange in living organisms Organs responsible for gaseous exchange in living organisms include the following: ORGANISMRESPIRATORY SURFACE AmoebaCell membrane InsectsTracheal system SpiderBook lung FishGills PlantsLeaves, stems, roots AmphibiansSkin, gills and lungs MammalsLungs BirdsLungs reptilesLungs Features of Respiratory Surface They are thin to reduce diffusion distance They are moist to dissolve gaseous so that they dissolve and diffuse in solution form They are highly braced, folded or flattened in order to increase the surface area for gaseous…

TOPIC 4: TRANSPORTATION OF MATERIALS IN LIVING THINGS The Concept of Transportation of Materials in Living Things The Concept of Transportation of Materials in Living Things Explain the concept of transportation of materials in living things Unicellular organisms (for example amoeba), nutrients (for example oxygen and food) and waste products (for example carbon dioxide) can simply diffuse into or out of the cells from the surroundings. But in multi cellular organisms (for example humans and trees), many cells are very far away from the body surface, hence a transport system is required for the exchange of materials. Organisms require transport…

TOPIC 3: BALANCE OF NATURE The Natural Environment The Concept of Natural Environment Explain the concept of natural environment Natural environment is made up of all living and non living things that occur naturally on earth. An organism living anywhere in any environment is affected by the things around it such as air, water, animals, plants, microorganism, stones, rock, soil, clouds and the sun. everything around it in fact makes its natural environment. It is important to understand that the environment includes all living things as well as non living things. IMPORTANT TERMS Ecology: is the branch of biology that…

TOPIC 2: NUTRITION Concepts of Nutrition and food Nutrients Meaning of nutrition: Nutrition is the process by which organisms take in and use nutrients. Nutrients are any substances that nourish an organism. Food is any material when taken in absorbed and utilized meet requirement of plant and animal body. The Concepts of Nutrition and Food Nutrients Explain the concepts of nutrition and food nutrients FUNCTION OF FOOD Oxidized to release energy Used in growth of cells Used to repair lost cells and tissue TYPES OF NUTRITION There are two main types of nutrition: autotrophic nutrition and heterotrophic nutrition. Autotrophic Nutrition…