2020 George Emmanuel College Form 1 Combined Science Notes By Kwari C C [Type here] FORM 1 COMBINED SCIENCE SECTION - BIOLOGY - CHEMISTRY - PHYSICS BIOLOGY: 1. Cells and levels of organization 2. Nutrition 3. Respiratory system 4. Transport systems 5. Reproduction in plants and animals 6. Health and diseases LABORATORY RULES AND SAFETY Syllabus objectives explain laboratory rules identify laboratory apparatus demonstrate use of laboratory apparatus What is combined science? It is a compound subject made up of three broad sections namely physics, chemistry and biology. KWARI C What is a scientist? A person who investigates the world around him and try to discover things. A scientist uses his senses and the brain to make observations, discoveries and gather information. He also uses apparatus scientist carry out experiments in a special room called laboratory. Laboratory safety 1. Do not eat in the laboratory 2. Do not taste anything in the laboratory unless you are told to do so. 3. Do not touch anything chemicals with bare hands. 4. Do not run in the lab 5. Do not make noise in the lab 6. Do not enter the lab without teachers permission 7. All accidents must be reported to the teacher immediately as well as unusual smells. 8. Understand all the instructions before carrying out an experiment Laboratory apparatus CELLS AND LEVELS OF ORGANIZATION KWARI C Syllabus objectives • describe the structure of a plant and an animal cell • list similarities and differences between plant and animal cells Biology -Biology is the study of living organisms. -All things are classified as living and non-living Plant cell Animal cell What is a cell It is the basic unit of all living things . Tissues are grouped together from organs and organs form a system. Examples of systems are blood circulatory system, urinary system. Organs and organ system together form an organism. Structure of a plant cell KWARI C Part Function Cell wall A Gives cell the same rigid shape and protects the cell Cell membrane Helps the substance move in and out Cytoplasm Thick jelly which contain the nucleus food particles and some waste Nucleus Controls the activities of the cell Permanent vacuole Helps to stretch the cell Chloroplast Traps sunlight Question Differentiate a plant and an animal cell Explain the functions of the following 1. Cell membrane 2. Cell wall 3. Vacuole 4. Chloroplast 5. Nucleus Identify similarities between the plant and animal cell KWARI C NUTRITION Syllabus objectives define balanced diet list component of balanced diet state functions of nutrients Plant produce food using raw material obtained from the soil and air. The production of food in plants only take place in the presence of sunlight (solar) energy by a process called photosynthesis. The food made by plants contain chemical energy. The word equation for photosynthesis Water + carbon dioxide +sunlight →carbohydrates and oxygen Other food nutrients produced by the plant proteins are proteins, fats, oils, mineral salts, vitamins, roughage (fiber) including water NB Plants are they only organisms that can use solar energy to chemical energy plants are called producers. Other organisms are consumers. Food chains is a linear feeding relationship. Maize plant- cow –person and lion Animal nutrition Diet is the pattern of what one eats every day. Balanced diet is the diet that contains all nutrients in their right amounts and proportions. Components of a balanced diet .A balanced diet is consist of carbohydrates, fats, iron, vitamins, roughage Carbohydrates The word carbohydrate refers to a chemical compound that contain the elements carbon, hydrogen and oxygen. Functions of carbohydrates. Carbohydrates give the body energy to do all the activities like walking, talking, thinking etc. KWARI C Sources of carbohydrates Proteins Functions of proteins. Are needed or building new tissues and for repairing the worn out tissues. Sources of proteins Sources of proteins are meat, milk and eggs Fats Functions of fats. Provide more energy than carbohydrates. KWARI C Sources of fats Cooking oil, margarine, peanut butter and fatty meat. Mineral salts Mineral salts functions. Mineral salts are needed in smaller quantities . calcium and phosphorus are used for bone and teeth formation. Sources Fish , eggs, dried vegetables, beans, meat and liver Vitamins They are needed in small quantities. They prevent certain diseases and malfunctions . Sources Fruits such as apples, pine apples, oranges etc KWARI C Water Functions Makes up more than 70 percent of the body. It enables all chemicals reactions to the place in the body. It dissolves nutrients. It is used to make body fluids Sources Fiber or roughage Functions It is used to help proper functioning of digestive system. It helps smooth movement of food and waste particles in the digestive tract. Sources Roughage are vegetables and fruits KWARI C RESPIRATION Syllabus objectives State the percentage composition of air Identify respiratory gases describe the test for carbon dioxide gas test for oxygen gas Energy is that which makes the things move and happen. The energy needed by animals to do all activities is obtained from food. After nutrients have been absorbed they are transported in the blood to body cells where they are needed. In the cells nutrients are further broken. Energy nutrients (simple /glucose simple sugar molecules) are processed in the body cells by oxygen obtained in the lungs through breathing. in the cells oxygen is used to burn oxidise sugar (glucose) to release energy. The products of oxidation are carbon dioxide, water and energy. This chemical process is called respiration The word equation for respiration Glucose+ oxygen →carbon dioxide + water +energy (heat) Respiratory system KWARI C Air is the mixture of gasses. Air is invisible. Air has mass and volume. Inhailing – taking in air Exhailing – taking out air Composition of air Gases present in air and their proportions Gases in the air Inhaled air Exhaled air Oxyen 20 16 Carbon dioxide 0,03 4 Nitrogen 78 78 Water vapour Variable Variable Breathing movements Breathing out (exhailing ) .The chest cavity moves inwards and down wards . the diaphragm moves upwards contracting expelling the air out. .Breathing in The chest cavity moves outwards. The ribs move outwards and upwards the diagragm moves upwards flattering the lungs expand taking in air KWARI C Experiment Aim Oxygen test Materials Wooden splint, burner gas jar containing air Method 1. Light the end of the glowing splint 2. Extinguish the flame so that the splint glow red. 3. Put the glowing wooden splint in gas jar A \ Observations Record the observation Conclusion Experiment Aim To test for carbon dioxide Materials Lime water, bicarbonate indicator, straws, test tubes Method 1. Pour a small amount ofg lime water or bicarbonate indicator into a test tube 2. Blow into the solution using a straw Observations Lime water Clear - milky Bicarbonate indicator Red to yellow KWARI C Conclusion ……Exhaled air has carbon dioxide TRANSPORT SYSTEM Syllabus objectives describe water movement in plants identify components of blood stating the functions of each component In an organism there are vast numerous numbers of cells. These cells need special living transport system to move various substances from place to place. Plant cells need carbon dioxide for photosynthesis to manufacture carbon dioxide. Oxygen is needed for respiration. Diffusion Diffusion is the movement of particles from the region of higher concentration to the region of lower concentration. Osmosis Is the movement of water molecules from the region of higher concentration to the region of lower concentration through a partially permeable membrane Outline the differences between diffusion and osmosis KWARI C TRANSPORT SYSTEM IN ANIMALS Syllabus objectives • Identify components of blood stating the functions of each component The body needs system to transport nutrients of the body. Oxygen should be carried from the lungs to all cells for them to respire and release energy. The transport system needs to remove waste materials e-g carbon dioxide , urine etc .Blood is a component that is used to transport materials around the body. The blood has four components these are plasma, red blood cells, white blood cells and Platelets Red blood cells Contain a substance called hemoglobin which blood its red color. The red blood cells absorb and transport oxygen White blood cells These defend the body against diseases by killing germs. White blood cells are for defense Platelets Are small components which initiate blood clotting to stop excessive bleeding. Plasma A clear liquid which contains 92 percent water. It has dissolved nutrients, antibodies, and proteins. It contains urea and carbon dioxide KWARI C REPRODUCTION Syllabus objectives describe structure of a simple flower describe pollination and fertilization state signs of puberty Reproduction Refers to the increase in population of organisms of one type. Reproduction is a process where young ones are produced by both plants and animals. In plants the main functions of flowers is sexual reproduction KWARI C 1 2 3 4 5 Stigma Style Ovary Ovule Petals Receives pollen grains during the process of pollination Produces a sticky substance to ensure pollen grains get stuck Supports the stigma Provides pathway for pollen tube to the ovules Produces ovules Later develops into fruit after fertilisation Are the female sex cells Develops into a seed after the process of fertilisation Attract insects for pollination by their bright colour and nice scent Their shape promotes pollination as they direct insects towards the nectaries 6 Sepals Protects the flower bud 7 Anther Produces pollen grains 8 Pollen grains These are the male sex cells Question Outline the functions of the Parts of the flower Fruit and seed dispersal This is the scattering of fruits and seeds by 1. Animals 2. Water 3. Wind 4. Self explosive mechanism e-g the munondo seeds. KWARI C Comparing wind pollinated and insect pollinated flower Wind –pollinated flower dull Insect pollinated flower 1. Are not small Are usually large 2. Do not produce a scent nector Produce a scent and nectar 3. Have long filament out of flower Have short filament 4. Usually do not have petals Have filaments that do not hang out Questions Explain the functions of the stigma, style, anther, filament Identify the male sex cells and the female sex cells KWARI C REPRODUCTION IN HUMANS Syllabus objectives • state signs of puberty Puberty or adolescence Is the stage at which children become sexually mature. In girls /females puberty is attained at 910 yrs . Sexual maturity in females The girls internal reproductive organs change. The vagina becomes deeper. Vaginal discharge occurs. The uterus become longer and the ovaries enlarge. Hips widen. Pubic hair grows and so does the armpit. Breast become bigger. Sexual maturity in males Pubic hair grows as well as hair take place under the armpit. Body hair may also grow on the chest. The voice breaks and the sound deeper. The penis becomes larger. Production of sperms begins. The shoulder become broader. Beard grows. Wet dreams start wet dreams is the release of sperms whilst asleep. Adolescence is the difficult stage for most people. At this stage adolescence get bossy, aggressive, shy, scared, outgoing to reserved. Sometimes teenagers become angry for nothing. Adolescence want to become independent. Boys and girls start relationships. Questions 1. Identify the similarities between the changes in girls and the changes in boys 2. Identify the differences between the changes in girls and the changes in boys 3. State any four pre-menstrual symptoms KWARI C Male Reproductive System Male and female sex cells KWARI C Female Reproductive System HEALTH AND DISEASES Syllabus objectives describe a healthy person state importance of maintaining personal hygiene list ways of disposing litter/ waste, stating their advantages and disadvantages describe methods of transmission of diseases Health is a state of physical mental and social well being. It does not simply mean the absence of diseases. Community health Avoid of diseases by proper sanitation and good hygiene. Use toilets, latrines avoid bush system Wash your hands each time you use the toilet. Drink clean water. put all waste in the bins and rubbish pits. houses should be kept clean. all liter should be placed in bin Individual / personal hygiene 1. our hands are the dirtiest parts of the body always wash your hands before handling food and after using the toilet 2. wash your hands with warm soapy water before handling food and always after using the toilets 3. the fingernail should be kept short 4. hair should be kept short and well combed. 5. underwear’s and shorts should be changed regularly and washed with soap and clean water 6. bath everyday and wear clean clothes 7. eat clean , warm or hot food 8. eat a balanced diet 9. relax and exercise regularly 10. get enough sleep of at least 8 hours 11. keep food covered KWARI C Causes of diseases Pathogens A pathogen is a disease causing micro-organisms e-g bacteria, virus, fungi, protozoa. The organisms are transmitted through air , water, food . a pathogen may stay on 1 part of the body can the whole body. Pathogen Way of transmission Disease Virus Air Influenza , measles, small pox Bacteria Water Cholera, typhoid Bacteria Air TB leprosy Fungi Contact Ring worm Protozoa Water Dysentery Worm Water Bilharzia Chemicals and poisons Smoke from factories, cigarettes, vehicle exhaust pollute the air. Factories produce poisons waste which causes fish and people to die. In the asbestos, cement and gypsum industries people get diseases like silicosis and asbestos which affect lungs. Alcohol, drugs, marijuana, glue, heroine cause people to engage in fights unreasonable arguments, stealing. Alcoholic suffer from liver and brain damage There are also some diseases which are called deficiency diseases. Genetic defects are diseases inherited from the parents such as dwarfism, albinism as well as down syndrome. Dwarfism –this is when the limb and the bones. Albinism –lack of pigment, melanin in the skin. Down syndrome –leads to mental retardation Disease transmission Is the spread of diseases? It can be by water, food, vectors, close contact and air Water Needed by all organisms makes about 70 percent of body. Pathogens spread through urine and faeces. They are discharged into the water sources. Pathogens are also spread through dirty water if used to clean clothes or wash utensils KWARI C Food As the house files walk on the faeces, hock and their sticky pads on its feet and its hairy body pick up pathogens. These pathogens are then deposited on food when the houseflies settle on food. The contamination of water and are cholera, dysentery and typhoid. Close contact Besides food and water, close contact can cause the spread of diseases. This happens mostly in crowded places. Close contact can lead to spread of scabies. When people share bed linen. Skin diseases are spread by skin to clothing to skin Air We need air to breathe in order to survive, but is the air that we breathe germs free. Air free can also be a means to the spread of diseases. The pathogens are carried in the air and spread to the other people. The method is called droplet infection. Tiny droplets containing germs may suffer from diseases like cold, TB, influenza if the pathogens are present in the large enough amounts. Leprosy is also transmitted by droplets infections Vectors Organism which transmit pathogens are called vectors. Examples are insects, rats and dogs. Mosquitoes spread malaria and files spread diarrhea. Prevention of spread of diseases The spread of diseases can be prevented by proper sanitation and good hygiene. Instead of using the bush system use toilets. Every time you use the toilet wash your hands with soap and clean water Symptoms of bilharzia The symptoms of bilharzia are itchy skin, fever, blood stained urine, diarrhea, Methods of preventing spread of bilharzia 1. Breaking the spread of bilharzia 2. Boiling drinking and washing water 3. Chlorination of water 4. Proper sanitation 5. Avoid playing in snail infested water KWARI C 6. Wearing protective boots 7. Building bridges over streams 8. Killing snails Malaria Malaria is a disease that is spread by female anopheles mosquito. Where do mosquito live in. mosquitoes live in marshy areas, tall grass and dark corners Transmission of malaria When the mosquito bites a person they suck blood containing malaria parasite called plasmodium. The plasmodium is a protozoa KWARI C
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