CELL PROPERTIES AND FUNCTIONS CELLULAR (INTERNAL/TISSUE) RESPIRATION The oxidation of glucose in the cell to release energy is known as cellular respiration and it occurs in the mitochondria of all living cells. There are two types of cellular respiration i.e. aerobic and anaerobic respiration AEROBIC RESPIRATION When cellular respiration takes place in the presence […]
CELL PROPERTIES AND FUNCTIONS Read More »
MODE OF NUTRITION AND PLANT NUTRITION AUTOTROPHIC NUTRITION Plants are referred to as autotrophs, i.e. being able to manufacture their food (Organic compound from inorganic materials such as water, carbon dioxide) Autotrophs generally have two modes of nutrition which are chemosynthesis and photosynthesis (holophytic). HETEROTROPHIC NUTRITION This is a type of nutrition in which
MODE OF NUTRITION AND PLANT NUTRITION Read More »
Environment/Nature and State of Matter Living cells are known to be surrounded by a watery environment. This may include: Fresh/salt water in which the unicellular organisms live, Intercellular fluid that bath the bodies of cells of higher animals. The nature of states of matter makes diffusion and osmosis possible. Matter can be defined as
CELL AND ITS ENVIRONMENT Read More »
THE CELL: DEFINTION, STRUCTURE, FUNCTIONS CELL THEORY DEFINITION AND FORMS OF CELLULAR EXISTENCE The cell is the simplest, smallest, basic, structural and functional unit of life. The cell can carry out all life activities such as growth, respiration e. t. c. Cells can exist in various forms which include As a single cell (unicellular forms)
THE CELL: DEFINTION, STRUCTURE AND FUNCTIONS Read More »
CLASSIFICATION OF LIVING ORGANISMS MODERN CLASSIFICATION OF LIVING ORGANISMS All organisms cannot be suitably classified as either plants or animals based on CarolusLinneaus classification. Therefore five kingdoms have been generally accepted for all living organisms, these include Monera, Protista, fungi, plantae and animalia. KINGDOM MONERA (Prokaryotes) This group consists of simplest living organisms (bacteria,
CLASSIFICATION OF LIVING ORGANISMS Read More »
CLASSIFICATION OF ANIMALS AND ORGANIZATION OF LIFE THE VERTEBRATES (PHYLUM CHORDATA) All vertebrates have the following features: A bilaterally symmetrical body which is divided into a head, trunk and a tail with a neck joining the head to the trunk in most vertebrates. An internal skeleton (endoskeleton) Well developed central nervous system and sense organs.
CLASSIFICATION OF ANIMALS AND ORGANIZATION OF LIFE Read More »
DIFFERENCES BETWEEN PLANTS AND ANIMALS All living organisms can be generally classified as plants or animals. However, plants can be distinguished from animals in the following ways: PLANTS ANIMALS 1. Undergo passive movement. Undergo free or active movement with well developed organs of locomotion. 2. Gaseous exchange takes place through the entire body. Gaseous
DIFFERENCES BETWEEN PLANTS AND ANIMALS Read More »
CHARACTERISTICS OF LIVING THINGS Everything in nature can be classified into two groups: living and non -living things. The living things can be distinguished from their nonliving counterparts through the following characteristics observable in all living things: MOVEMENT: Animals can move from place to place on their own in search of food. Higher plants move
LIVING THINGS AND NON LIVING THINGS Read More »
MICROSCOPE PARTS AND FUNCTIONS A microscope is an instrument used in magnifying and viewing organisms smaller than 0.1mm that is too tiny to be seen by the human eyes. A compound light microscope consists of the following parts: Revolving nose piece: it is used for selecting lens to be used and to be in line
MICROSCOPE PARTS AND FUNCTIONS Read More »
PROCESS OR METHOD OF SCIENCE This is a systematic approach used to investigate enquiries arising from any observation made in nature. Therefore, the scientific method is the tool used to unravel the mysteries of life. The scientific methods include the following steps: Observation Classification Inference Measurement and Identification Hypothesis Experiment Control or Conclusion Theory or
PROCESS OR METHOD OF SCIENCE Read More »
BIOLOGY AND LIVING THINGS BIOLOGY AS AN INQUIRY IN SCIENCE Science is the study of nature (living and non-living things). Biology is a science that studies living things in nature. Biology was formed from the Greek words “Bio” (meaning life) and “logos” (meaning, study of). The organisms studied in biology are generally classified into plants
BIOLOGY AND LIVING THINGS Read More »
JAUNDICE (SKIN AND EYES) This is a yellow colouration of the skin and eyes. Cause: Presence of excess bile pigments. This happens due to blockage of bile duct or destruction of liver. Symptoms: Yellow pigmentation of skin and eyes, nausea, vomiting and lack of appetite. Itching of skin. Treatment Removal of stones from the gall bladder
JAUNDICE (SKIN AND EYES) Read More »
LIVER EXCRETION Role of Liver in Excretion The liver lies below the diaphragm and it receives blood from hepatic artery and hepatic portal vein. Blood flows out of the liver through hepatic vein. Excretion of Nitrogenous Wastes Excess amino acids cannot be stored in the body; they are deaminated in the liver. Hydrogen is added
STRUCTURE AND FUNCTIONS OF THE KIDNEYS The kidneys are organs whose functions are excretion, osmoregulation and regulation of pH. Kidneys are located at the back of the abdominal cavity. Each kidney receives oxygenated blood from renal artery, while deoxygenated blood leaves through the renal vein. Urine is carried by the ureter from the kidney to
STRUCTURE AND FUNCTIONS OF THE KIDNEYS Read More »
EXCRETION AND HOMEOSTASIS (PLANT AND ANIMAL) Introduction What is Excretion? Excretion is the process by which living organisms separate and eliminate waste products of metabolism from body cells. If these substances were left to accumulate, they would be toxic to the cells. Egestion is the removal of undigested materials from the alimentary canals of animals.
EXCRETION AND HOMEOSTASIS (PLANT AND ANIMAL) Read More »
DISEASES OF THE RESPIRATORY SYSTEM Asthma Asthma is a chronic disease characterized by narrowing of air passages. Causes: Allergy Due to pollen, dust, fur, animal hair, spores among others. If these substances are inhaled, they trigger release of chemical substances and they may cause swelling of the bronchioles and bring about an asthma attack. Heredity
DISEASES OF THE RESPIRATORY SYSTEM Read More »
Factors that cause a decrease or increase in energy demand directly affect rate of breathing. Exercise, any muscular activity like digging. Sickness Emotions like anger, flight Effects of Exercise on Rate of Breathing Students to work in pairs. One student stands still while the other counts (his/her) the number of breaths per minute. The
FACTORS AFFECTING RATE OF BREATHING IN HUMANS Read More »
GASEOUS EXCHANGE IN A MAMMAL – HUMAN The breathing system of a mammal consists of a pair of lungs which are thin-walled elastic sacs lying in the thoracic cavity. The thoracic cavity consists of vertebrae, sternum, ribs and intercostal muscles. The thoracic cavity is separated from the abdominal cavity by the diaphragm. The lungs
GASEOUS EXCHANGE IN A MAMMAL – HUMAN Read More »
GASEOUS EXCHANGE IN AN AMPHIBIAN – FROG An adult frog lives on land but goes back into the water during the breeding season. A frog uses three different respiratory surfaces. These are the skin, buccal cavity and lungs. Skin The skin is used both in water and on land. It is quite efficient and
GASEOUS EXCHANGE IN AN AMPHIBIAN – FROG Read More »
GASEOUS EXCHANGE IN BONY FISH (E.G. TILAPIA) Gaseous exchange in fish takes place between the gills and the surrounding water. The gills are located in an opercular cavity covered by a flap of skin called the operculum. Each _gill consists of a number of thin leaf-like lamellae projecting from a skeletal base branchial arch (gill
GASEOUS EXCHANGE IN BONY FISH (E.G. TILAPIA) Read More »