Express Notes Science Form 3

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Transcript of Express Notes Science Form 3

  • 1. Written ByNg Chee Kin B.Sc.(Hons.), [email protected] Rights Reserved 2012 Ng Chee Kin

2. Page 1 PREsSS E X p r eu.a3. When oxyhaemoglobin reaches the body cells, it4. The oxygen is then absorbed by the body cellsCHAPTER 1om breaks down and releases oxygen. for cellular respiration. Respiration 1.1Human Breathing MechanismOxygenOxygenated blood returns Oxygenated bloodt.c to the heart pumped out of theOther1. The human respiratory system:Heart heart Oxygen enters blood inbody Blood capillaries Trachea the lungs cells around the alveolipo Deoxygenated blood Deoxygenated blood Bronchus Lungspumped out of the heartreturns to the heart Lung (plural: bronchi)gs Key:Movement of oxygenHaemoglobin Bronchiole Movement of oxygenated bloodOxyhaemoglobin iii Movement of deoxygenated blood loAlveolus1.3 The Importance of a Healthy Respiratory CHAPTER 2(plural: alveoli)Bronchioles .bSystemBlood Circulation and Transport1. Chemical substances which are harmful to the2. The air flow during inhalation: 2.1Transport System in Humans respiratory system are:in NoseTracheaBronchusBronchiole (a) nicotine, tar and carbon monoxide from1. The human heart:Alveolus cigarette smoke (b) sulphur dioxide, nitrogen oxide, carbon AortaekVena cava3. The air flow during exhalation: monoxide, asbestos dust, coal dust andPulmonary artery hydrocarbons from vehicles and factories. Semilunar AlveolusBronchiole Bronchus valves2. Tar and asbestos dust are carcinogenic, which Pulmonary Trachea Noseveinhe means they can cause lung cancer if inhaledRight excessively. atrium 1.2Transport of Oxygen in the Human BodyLeft atrium3. Bacteria, viruses and other microorganisms1. The oxygen dissolves in the moist lining of the produce toxins which cause illnesses. Tricuspid Bicuspid rc valve valve alveolus and then it diffuses into the blood 4. We need to improve the quality of air in order preserve healthy respiratory system.Left2. In the blood capillaries, oxygen will combineRight ventricle m with haemoglobin in the red blood cells to formventricle oxyhaemoglobin.SeptumTWB Sci F3 (Exp Note) A 2nd.indd 3 5/26/2009 4:12:56 PM 3. Page 2Pulmonary artery Aorta4. Path of blood flow in the circulator system:5. Double circulatory system: Pulmonary(a) Deoxygenated blood is pumped from theVena cavaveinheart to the lungs and oxygenated blood uDeoxygenated OxygenatedRight atriumSemilunarblood bloodflows back again to the heart.(b) Oxygenated blood is pumped from the heat .avalvesVena cava to the rest of the body and deoxygenatedLeft atrium Lungblood flows back again to the heart. 6. Human blood transports many substances in our om Bicuspid body.Tricuspidvalve Right LeftvalveatriumatriumSeptum Substance Right From To Left ventricle transported ventricle t.c Right LeftOxygen (in LungsAll body Cardiac muscle ventricleInternal organsventricle the form of cells (for example, oxyhaemoglobin) Deoxygenated bloodOxygenated bloodliver, gut) Carbon dioxide All body cells Lungs po Digested foodSmallLiver and2. Functions of the heart: (glucose, aminointestineall body (a) Pumps blood to all parts of the body. acids)cellsgs (b) Transports nutrients and oxygen to the bodyRest of the body (forWaste materialsLiver andKidneys cells. example, head, arms, (such as urea) cells (c) Transports carbon dioxide and waste iv legs) materials from the body cells.Hormones EndocrineTargetlo3. Types of blood vessels:glands organsCharacteristic Artery Vein Capillary Structure Connective tissue.b Connective tissue 2.2Human Blood 1. Human blood consists of:in(a) 55% plasma LumenSmoothLumenSmooth Lumen Endothelium muscle (b) 45% blood cells and plateletsmuscle 2. Types of blood cells:ek Endothelium EndotheliumTypeFunction Size of lumen SmallLargeVery smallRed blood cells Carries oxygen from the lungs to the body cellshe Thickness of wall Thick, muscular, elastic Thin, less elastic,Only one cell thick and White blood Defends the body againstmuscular not muscular cells diseases Speed of blood flow RapidSlow Very slow Platelets Helps in blood clottingrc Blood pressureVery high pressure Low pressure Very low pressure 3. Functions of blood:(a) Transports gases and dissolved substances Presence of valvesNo except at aorta and YesNo m(b) Protects the body against diseases pulmonary artery (c) Maintains the body temperature at 37oCTWB Sci F3 (Exp Note) A 2nd.indd 4 5/26/2009 4:12:58 PM 4. Page 34. Compatibility of blood groups:4. Transpiration is the process by which plant loses3.2The Urinary System in Humanswater, in the form of water vapour. Recipients blood 5. Transpiration happens through the stomatau Donors group A BAB O Vena cava Aorta(singular: stoma), tiny pores on the leaves of blood groupthe plant. .aAdrenal A 6. Factors that affect the rate of transpiration: Renalgland(a) Light the brighter the light, the greatervein B Renalthe rate of transpiration. om AB artery(b) Temperature the higher the temperature, O the greater the rate of transpiration. Right Left(c) Humidity the lower the humidity, the kidneykidney5. Universal donor is a person with blood group O.greater the rate of transpiration.6. Universal recipient is a person with blood groupt.c(d) Wind the faster the movement of air, theUreters AB.greater the rate of transpiration. 7. Transpiration helps plants to absorb and transportUrinary 2.3Transport System in Plantswater and minerals. bladderpo1. The transport system in plants is called theUrethra vascular system.2. There are two main vascular tissues:CHAPTER 3 (a) Xylem- transports water and mineral saltsExcretion gs from the roots to the leaves Cortex (b) Phloem- transports glucose from the leaves 3.1Human Excretion v to all parts of the plants lo3. Xylem and phloem are found in the vascular1. Excretion is a process of eliminating wasteCortex Medulla bundle.products from the body. Xylem Medulla 2. The organs responsible for removing waste .bproducts are called the excretory organs. Renal artery 3. The waste products removed from the body are PhloemPyramidcalled the excretory products. in Cross section of leafRenal vein Pelvis Epidermis Excretory organExcretory productsek Phloem vascular Xylem bundleSkin Water, mineral salts, urea Ureter pith LungsWater, carbon dioxide heCross section of stem KidneysWater, mineral salts, urea1. The human urinary system consists of: kidney, Root hair ureter, bladder and urethra. Cortex4. Excretion helps to maintain the balance of water2. Functions of kidneys:rcEndodermiscontent, chemical composition and pH in the(a) To filter blood. Xylembody system. (b) To remove urea, excess mineral salts and Phloemwater to form urine. m Epidermis (c) To control the balance of water and chemical Cross section of root in the body.TWB Sci F3 (Exp Note) A 2nd.indd 55/26/2009 4:13:02 PM 5. Page 43. Kidney failure happens when the kidneys of 6. Most nitrogenous wastes are very poisonous.4.2 Male Reproductive System a person unable to perform their functions 7. Some excretory products of plants are useful properly. to humans such as: morphine, opium, cocaine,uOrgan Function4. Kidney failure can be treated through dialysistannins and oils. or kidney transplant. .aTestis (plural: Produces sperms (the male5. Dialysis is a method used to filter and remove testes) gametes) waste products from the blood of a patient.CHAPTER 4 Produces male sex hormones Reproductionom 3.3Excretion in Plants Scrotum Holds and protects the testes1. Plants excrete waste products mainly through4.1Understanding SexualandAsexualSperm duct Transports sperms from the simple diffusion.Reproduction(vas deferens)testes to the urethra inside2. Excretion in plant is mainly done through the t.c1. Reproduction is a process of producing new the body cell wall and stomata. individuals by living organisms.3. Mineral salts such as calcium carbonate and2. Importance of reproduction:Urethra Allows sperms to flow out of calcium oxalate are retained in the plant as (a) To increase the number of individuals of the the body crystals.po same species.4. Minerals such as silicon salts are deposited in the (b) To ensure certain species does not becomePenis Transfers semen into vagina leaves to strengthen the leaf blade. extinct. during copulation5. Nitrogenous waste products are removed when3. Types of reproduction: gs plants shed their leaves, flowers or bark.Seminal Secrete fluid which containsvesiclesnutrients for the spermsReproduction vi lo SexualAsexual1. Sperm:(Involving the male and the female gametes)(a) It is the male sex cell. AnimalsPlant Binary fission(bacteria) .bRegeneration (planaria)Budding (yeast) (b) It is produced by the testes. (c) It is also the smallest cell in the malesbody. in(sperm and ovum)(pollen grainSpore formation Vegetative(d) It is shaped like a tadpole, which has a head, and ovule)(moss, ferns and fungi)reproductionneck, middle piece and tail. (e) The head contains a nucleus which hasekgenetic material. (f) The tail helps the sperm to move or swim inSeminal vesicleVas deferensSeminal the female reproductive system.Vas deferensvesicle 2. Males reach puberty at 12 to 14 years old, whichhe Prostate gland is later than girls.3. There are physical, emotional and physiological EpididymisUrethraProstatechanges during puberty.rcUrethragland4. The testes start to produce sperm and male sex PenisPenis hormones during puberty. Testis Scrotum m Scrotum TestisTWB Sci F3 (Exp Note) A 2nd.indd 6 5/26/2009 4:13:03 PM 6. Page 5 4.3Female Reproductive System1. Ovum (plural: ova): (c) Fertile phase / ovulation phase (day 12 to 16) (a) It is the female sex cell.(d) Premenstrual phase (day 17 to 28)Oviduct (Fallopian tube) (b) It is produced by the ovary. 6. Women of about 50 years of age undergou (c) It is the largest cell in the females body.menopause when their menstruation stops. (d) It is spherical in shape, which contains a .a nucleus and cytoplasm. 4.5 Fertilisation and Pregnancy (e) The nucleus contain genetic ma