RESPIRATORY SYSTEM IN MAMMALS The respiratory system of mammals is the most complex of all respiratory systems. It comprises a pair of lungs enclosed in the thorax and connected to the outside by a series of branched air tubes. In human beings, air can be drawn in through the mouth or nose. Both lead into […]
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DEFINITION/PHASES OF RESPIRATION The process of respiration involves the taking in of oxygen its transport within the body of the organism, its exchange in the cells and the eventual release of energy in form of ATP, water and carbon(IV)oxide. The energy is utilized by the cells for their daily activities. Respiration can therefore be defined
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In simple unicellular plant materials are exchanged by simple diffusion process between the plants and its aquatic environment. Hence there is no need for elaborate transport system. However, in higher plant such as ferns and the flowering plants. There is a need for elaborate transport system for transporting water and mineral salts from the soil
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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 defends the body in major ways Antibody production (Clumping): The lymphocytes produce antibodies which are any of a large variety of proteins normally present in
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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 e.g. crustaceans. It captures its food through its structure called nematocysts found on its tentacles. The food is then passed into the mouth while the
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TYPES OF TEETH Human beings have two sets of teeth in their lifetime. The first set is called the milk teeth that grow when the child is few months old. They are about twenty (20) in numbers. These include only three types of teeth i.e. Incisors, canine and premolars. They later fall off to be
To carry out life processes, all organisms (plants and animals) need tissues. Tissues are group of similar cells that carry out specific functions. Skeleton is the framework of the body which provides support, shape and protection to the soft tissues and organs in animals. It forms the central core of human body and it is
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LOCATION AND STRUCTURE OF CHROMOSOMES Chromatin granules (thread – like structures) found in the nucleus of eucaryotic cells are the precursors or raw materials of chromosomes. Chromosomes occur in pairs known as homologous chromosomes. Each chromosome is made up of two threads called chromatids joined at a point called centromere. Each human somatic cell
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Genetics is the scientific study of heredity and variation in all living things. The word genetics was coined by Dilliam Bateson (1906
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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 and functions among organism. The basis of evolution is that all organisms have pre–existing ancestors. Evidences of evolution Fossil record: A fossil is an
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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 mates and ensure their survival. Adaptive colouration may be grouped into Concealing (cryptic) colouration to help organisms blend with their background and remain unnoticed by predators Colour blendingwith the environment
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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 resources in plants include; light, space, nutrient and water while animals complete for food, space or mate. Competition finally results in survival of the fittest and elimination of the unfit.
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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 not undergo fertilization for the formation of their fruit. Such fruits are called parthenocarpic fruits e.g. banana and pineapple. Such fruits are seedless. A typical fruit has the following parts
Growth is defined as an irreversible increase in volume, size, and number of parts, length and weight of an organism It is an organic process which takes sometimes to accomplish. The three processes involve in growth are Cell division:- is a process by which cell increases in number and is achieved by cell division called
Ecology This is the study of living organisms (plants and animals) in relation to their environment. Ecology is divided into two main branches. AUTECOLOGY– is the study of an individual organism or a single species of organism and its environment. For example, the study of a single and its environment. SYNECOLOGY-is the study of the
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Autotrophic Nutrition This is the type of nutrition in which the organisms are able to manufacture their own food. Organisms which can manufacture or synthesize their own food are called autotrophs. Autotrophic nutrition is carried out by all green plants through the process of photosynthesis and by some certain bacteria through the process of chemosynthesis
ANIMAL NUTRITION (FOOD SUBSTANCES) Food is a complex energy-rich organic matter which living organism feed on to obtain nutrients and substances necessary for life. Food substances are classified to six groups (i) Carbohydrate (ii) Protein (iii) Fat and oils (iv) Mineral salts (v) Vitamins (vi) Water and roughages. Carbohydrates These are made up of carbon,
Nutrient cycle is defined as the circulation of certain nutrient such as carbon, sulphur and water in nature Carbon Cycle The carbon cycle is the way carbon (iv) oxide is being used from the atmosphere by photosynthesis and put back into the atmosphere by respiration and decay. The carbon cycle involves the following processes Photosynthesis,
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Nutrition is defined as the process by which living organisms obtain and utilize food material from external environment for metabolic activities such as respiration, growth, excretion and reproduction. Photosynthetic or holophytic Nutrition is defined as a process whereby green plant manufacture their own organic food from simple inorganic substances such as carbon (iv) oxide, water,
Organization of life is defined as the existence of life from a single called organisms to a multicellular organisms with complex form that perform different functions Levels of Organization 1 First level (cell): A cell which is the functional and structural unit of protoplasm bounded by a membrane is the first level of organization. It
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