Mr. FAROUK J. T

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…

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…

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…

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…

Factors that cause a decrease or increase in energy demand directly affect rate of breathing. Effects of Exercise on Rate of Breathing Dissection of a Small Mammal (Rabbit) to Show Respiratory Organs

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…

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…

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…

Gaseous exchange in insects e.g., grasshopper takes place across a system of tubes penetrating into the body known as the tracheal system. The main trachea communicate with atmosphere through tiny pores called spiracles. Spiracles are located at the sides of…

All animals take in oxygen for oxidation of organic compounds to provide energy for cellular activities. The carbon (IV) oxide produced as a by-product is harmful to cells and has to be constantly removed from the body. Most animals have…

Gaseous exchange takes place by diffusion. The structure of the leaf is adapted for gaseous exchange by having intercellular spaces that are filled. These are many and large in the spongy mesophyll. When stomata are open, carbon(IV)oxide from the atmosphere…

The water lily, Salvia and Wolfia whose stems remain in water are permeable to air and water. Oxygen dissolved in the water diffuses through the stem into the cells and carbon (IV) oxide diffuses out into the water. Gaseous Exchange…

Living organisms require energy to perform cellular activities. The energy comes from breakdown of food in respiration. Carbon (IV) oxide is a by-product of respiration and its accumulation in cells is harmful which has to be removed. Most organisms use…

Oxygen is required by plants for the production of energy for cellular activities. Carbon (IV) oxide is required as a raw material for the synthesis of complex organic substances. Oxygen and carbon (IV) oxide are obtained from the atmosphere in…

Making of beer and wines. Ethanol in beer comes from fermentation of sugar (maltose) in germinating barley seeds. Sugar in fruits is broken down anaerobically to produce ethanol in wines. In the dairy industry, bacterial fermentation occurs in the production…

Carbohydrate, mainly glucose is the main substrate inside cells. Lipids i.e. fatty acids and glycerol are also used. Fatty acids are used when the carbohydrates are exhausted. A molecule of lipid yields much more energy than a molecule of glucose.…

Aerobic respiration results in the formation of simple inorganic molecules, water and carbon (Iv) oxide as the by¬products. These cannot be broken down further. A lot of energy is produced. When a molecule of glucose is broken down in the…

To Show the Gas Produced When the Food is burned A little food substance e.g., maize flour or meat is placed inside a boiling tube. The boiling tube is stoppered using a rubber bung connected to a delivery tube inserted…

Respiration is the process by which energy is liberated from organic compounds such as glucose. It is one of the most important characteristics of living organisms. Energy is expended (used) whenever an organism exhibits characteristics of life, such as feeding,…

An allergy is a hypersensitive reaction to an antigen by the body. The antibody reacts with the antigen violently. People with allergies are oversensitive to foreign materials like dust, pollen grains, some foods, some drugs and some air pollutants. Allergic…