science definitions form 3

CassiaFany © Words

Definition

Human respiration system

Provides an area for gas exchange between the bolld and the environment. It allows oxygen acquisition and carbon dioxide elimination. The gas exchange in lungs which involves the taking in and letting out of air. A sheet of muscle which separates the thoracic cavity from the abdomen. Consists of the taking in of air (inhalation) and the letting out of air (exhalation). The air that reaches the alveoli which is rich in oxygen and poor in carbon dioxide. The prosses of gas exchange. An oxygen-carrying pigment in red blood cells. The combination of oxygen and haemoglobin. Substances that cause cancer. Fine particles in the air Caused by the narrowing of the fine airways (bronchi and bronchioles) due to the contraction of muscles in their walls. A condition characterised by a recurrent or chronic cough every day over a period of several months. An early sign of chronic bronchitis. Lumps of cells which interfere with the normal functions of the lungs. A condition in which the structure of the alveoli is broken down by coughing. This reduces the surface area for gas exchange. Delivers useful materials to the body cells and remove the waste materials from them. Is called the internal transport system because useful materials as well as waste materials circulate the body. Blood transports useful and wasteful materials. Heart. Blood is moved through the body by muscular contractions of the heart. A complex network of blood vessels carries materials to the tissues and back to the heart. Arteries, veins and capillaries. Present in some blood vessels to prevent backflow and ensure that blood flows in one direction only. In each complete circuit of the body, the blood must flow through the heart twice. Transports blood between the heart and the lungs Transports blood between the heart and all other parts of the body. Supply nutrients and oxygen to the muscles. Removes waste from the muscles. Prevent the backflow of blood into the ventricles. Prevent the valves from turning inside out when the ventricles contract. Blood vessels which carry blood away from the heart. Blood vessels which carry blood back to the heart. Tiny blood cells which connect arteries and veins. The combination of carbon dioxide with haemoglobin. Heredity is the passing of traits to offspring from its parents or ancestor.

Breathing (external respiration) Diaphragm The breathing mechanism Alveolar air Diffusion Haemoglobin Oxyhaemoglobin Carcinogens Particulate matter Asthma Chronic bronchitis Smoker’s cough Tumours Emphysema Internal transport system Circulatory system Circulating fluid Pumping device Blood vessels

Valves Double circulatory system Pulmonary circulation Systemic circulation Coronary arteries Coronary veins Semilunar valves Chordae tendineae Arteries Veins Capillaries Carbaminohaemoglobin Heredity

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CassiaFany © Cardiologist

A doctor who has special training and skills in finding, treating and preventing diseases of the heart and blood vessels. Centrifugation The process of the separation of the major composition of blood. Plasma The pale-yellow liquid component of blood that normally holds the blood cells in whole blood in suspension. It makes up about 55% of the body's total blood volume. Nutrients Glucose, amino acids and vitamins Proteins Antibodies, hormones, enzymes, albumins and fibrinogen Inorganic ions Sodium, calcium, chlorides and phosphates. Red blood cells Bioconcave, disc-shaped cells without nucleus. (erythrocytes) Transports oxygen from the lungs to all parts of the body. Bone marrow cells Forms red blood cells and white blood cells. White blood cells Irregular in shape, colourless, with nucleus and do not contain (leucocytes) haemoglobin. Platelets (thrombocyctes) Cell fragments produces by large cells in the bone marrow. The ABO system Classifies the human blood into four main groups called A, B, Ab and O. Agglutinate Clump together Universal donors People with blood group O who can safely donate blood, in small quantities, to anyone. Universal recipients Group AB people who can safely receive blood from anyone. Wilting Occurs in non-woody plants when water loss through the aerial parts of the plant exceeds water absorption by the roots. Turgidity Stiffness Transpiration The evaporation of water from the aerial parts of plants. Guard cells A pair of bean-shaped cells which bound each stomata, Stomata Pores in the epidermis of the leaves and stems. Allows gases to diffuse in and out of the leaf. Xylem Transports water and mineral salts from the roots to the stems and leaves. Provides support to the plants. Lignin Lignin or lignen is a complex polymer of aromatic alcohols known as monolignols. It is most commonly derived from wood, and is an integral part of the secondary cell walls of plants and some algae. Phloem Transports synthesized food substances from one part of the plant to another. Sieve tubes Living cells without nucleus. The walls of sieve tubes are composed largely of cellulose. Sieve plates Transverse walls of sieve tubes which are perforated by pores. Companion cell Each sieve tube has a companion cell beside it. Girdling The technique of the cutting off a complete ring of bark including the phloem and cambium from the stem just above ground level. The xylem tissue is left intact. Metabolism Refers to all the chemical processes that take place in the body which may result in the production of waste products which are often toxic. Excretion The elimination of metabolic waste products from the body which is done by excretory organs. Defacation Not excretion because faeces contain undigested food which has not been absorbed into the cells or taken part in metabolism. Skin Has many sweat flands which leads to a sweat duct which opens on the skin surface as a sweat pore.

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CassiaFany © Lungs Kidneys

Urine Renal artery Renal vein Ureter Urinary bladder Urethra Urinary tract Urologist Cortex Medulla Pyramids Pelvis Nitrogenous waste products Dialysis machine/ kidney machine Dialysis tube Dialysate Diffusion Kidney transplant Reproduction

Asexual reproduction

Binary fission Budding Spore formation Sporangium Vegetative reproduction Runner

Bulb

During cell respiration, the cells produce carbon dioxide and water as waste products. The main organs in the excretory system. Filters blood and produce urine. Keep water and mineral contents in our body in balance. Control the amount of mineral salts in the body fluid. Help to maintain the pH of blood and tissue fluid. A yellowish liquid that contains water, mineral salts and urea. Waste products and excess substances are converted into urine. Carries blood to each kidney Carries blood away from each kidney. Carries urine from the kidnetys to the urinary bladder. Stores urine and gradually expands like a balloon. Expells urine to the exterior The system of tubes leading from the kidney to the exterior. A doctor who is concerned with diseases of the urinary tract. The dark-red outer region of the kidneys The pale-red inner region of the kidneys The medulla is filled with cone shaped tissues called pyramids. The apices of the pyramids open into a funnel shaped cavity called the pelvis which drains urine into the ureter. Urea, excess water and mineral substances Works in similar ways to the real kidneys. A long cellophane tube which allows blood to flow through in the machine. Surrounds the dialysis tube. Contains dissolved sugar and salts just like plasma. Does not contain urea. The passing of urea and excess salts from the blood flowing within the tube into the dialysate. The dialsate is discarded. A kidney from a suitable donor can be transplanted into the patient. The production of a new generation of individuals (offspring) from preexisting ones (parents) to ensure the continuity or perpetuation of the species. A rapid method of increasing the number of new individuals which are formed from one parent and they are genetically identical to each other and the parent. The unicellular organism divides into two equal parts (daughter). The parent produces an outgrowth or bud which detaches to become a new individual. Formed in sporangium. Each spore can develop into a new individual. A spore-bearing structure. Part of a plant (root, stem, leaf or bud) detaches and grows into a new plant. A slender shoot that arises in the axil of a leaf and grows horizontally on the surface of the ground. The runner bears roots and becomes independent before the parent plant dies. Short stem and fleshy leaves containing food (mainly sugar) New shoots arise from buds in axils of the fleshy leaves.

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CassiaFany © Rhizome

Corm Stem tuber Rejuvenation Vegetative propagation Sexual reproduction Fertilisation Zygote Internal fertilisation

External fertilisation

Testes (singular: testis) Scrotum Penis Epididymis Sperm ducts Urethra Seminal vessicle Prostate gland Cowper’s gland Sperms

Larynx Ovary Fallopian tube (oviducts) Uterus Cervix Vagina Ovum

Menstrual cycle

A horizontally growing underground stem wich stores food. It produces lateral buds, some of which develop into shoots. When the old rhizone dies, the new shoots become independent plants. A short, vertical, underground stem which stores food. It is protected by scaly leaves. Buds are located at the axils of these leaves. The swollen ends of underground stems. New shoots sprout out from axillary buds or ‘eyes’. The replacement of parts of an organism that are lost due to injury. Rejuvenation in plants. Whole plants can be grown from cuttings and grafts. The production of offspring by the fusion of specialised sex cells or gametes. The process of the fusion of the male gamete (sperm) with the female gamete (ovum or egg) which results in the formation of a zygote. The result of fertilisation which will develop into a new individual. Sperms are deposited in the female reproductive tract and fertilisation occurs within the body of the female. The zygote develops internally and live individuals are born. (aquatic organisms) Sperms and eggs are shed into the water in great numbers simultaneously. Only small number of the eggs are fertilised by the sperms. Produce sperms Holds the testes outside the body. Protects the testes. Places sperms in the vagina during sexual intercourse. Stores sperms Carry sperms from the testes to the urethra. Carries sperms and urine out of the body. Secretes fluid that provides nourishment to the sperms. Secretes fluid that neutralises the acidity of urine and the female vagina. Secretes a lubricating fluid that aids sperm movement. The male gametes consisting of a head, a middle piece and a long tail. Swims towards the female gamete (ovum) and fuse with it to form a zygote which will develop into an adult individual. Voice box Produces ovum (egg) Carries ovum from the ovary to the uterus Place where the embryo develops Secretes mucus that enhances sperm movements into the uterus. Prevents large foreign bodies from entering the uterus. Place where sperms are deposited. Birth canal. The female gamete, a spherical shaped cell which fuses with the sperm to form a zygote during fertilisation. Stores some food in its cytoplasm which is used to nourish the embryo which develops from the zygote. The repeated cycle of events which occur every 28 days from puberty (when ovum production begins) to menopause (when ovum production stops). To provide a favourable environment in the uretus for the development of the zygote.

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CassiaFany © Menstruation phase (1-5) Repair phase (6-11) Ovulation (14) Fertile phase (12-16) Premenstrual phase (1728)

Fertile period Sanitary pads

Tampons Fertilisation Pregnancy Embryo Implantation Placenta

Foetus Umbilical cord Umbilical artery Umbilical vein Amnion Amniotic fluid Gestation period Birth

Foetal Alcohol syndrome (FAS) Sterility/ infertility Procreate

The discharge of the uterus lining, unfertilised egg and blood through the vagina. Rebuilding and thickening of the uterus lining. Release of ovum from the ovary. Continued thickening of the uterus lining by increasing blood supply and tissue. It gets ready for implantation of embryo, if fertilisation is successful. If not, the uterus lining begins to break down and the nexy cycle begins. The period around the time of ovulation when a woman can become pregnant if she has an intercourse. (11-17) Sanitary towels are worn as a lining on the underwear to absorb the menstrual discharge. This will prevent the discharge from staining the clothes. Inserted into the vagina to absorb menstrual disharge by means of an applicator. The process whereby the sperm fuses with the ovum to form the zygote. It occurs in the upper part of the Fallopian tube. The rapid growth and development of a baby between the zygote stage and birth. A ball of cells formed from a zygote. The process of the embedding of the embryo in the tissues of the uterus lining about seven days after fertilisation. A large disc which is formed from the firm binding of of the surfaces of the embryo and the uterus lining. Nourishes the embryo. By eight weeks after fertilisation, the developing embryo becomes clearly human and is called a foetus. Attaches the foetus to the placenta. Carries carbon dioxide and other wastes from the foetus to the placenta. Carries blood containing oxygen and food from the placenta to the foetus. A membrane which completely covers the foetus and is filled with amniotic fluid. Protects the embryo and later the foetus by cushioning it from physical damage. The time for the full development of a foetus, which is forty weeks. Occurs in three stages: - The expansion of the cervix so that the baby’s head can pass into the vagina. - The strong contractions of the uterus which push the baby out of the mother’s body. - Further contractions of the uterus to expel the umbilical cord and placenta from the mother’s body. FAS babies have mental retardation, small brains, poor muscle bone, low birth weight and behavioural problems such as hyperactivity poor concentration. Caused if the mother drinks heavily during pregnancy. The failure of a couple to procreate despite seriously attempting to do so for at least 12 months. To reproduce

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CassiaFany © L-arginine Hormone treatment In-vitro fertilisation (IVF) Catheter Family planning/ birth control Rhythm (natural)

Condom (Mechanical) Intrauterine contraceptive device (ICUD) (Mechanical) Contraceptive pills (Hormonal) Spermicides (Chemical) Vasectomy (Surgical) Tubal ligation (Surgical) Diaphragm with spermicide (Mechanical and chemical) Injection (Depo-Provera) (Hormonal) Flowers Unisexual flowers Bisexual flowers Pollen grains Receptacle Sepals Petals Stigma Style Ovary Ovule Anther Filament Pollination Agents of pollination Self-pollination

Cross-pollination Cross breeding

Necessary to maintain a normal sperm count. The injection of small amounts of specific female sex hormones into the body to stimulate the eggs to mature and to induce ovulation. ‘test-tube baby’ treatment. Transfers one or more embryos from a petri dish in an incubator into the woman’s uterus for implantation to take place. Most coules have the idea of planning for an ideal family size. Using cervical mucus changes and body temperature measurements to estimate the time of ovulation and avoiding intercourse during the fertile period. Thin, disposable latex sheath placed over the penis prior to intercourse to prevent sperm from entering vagina. Small plastic or copper device that is placed into the uterus by a doctor to prevent implantation. Pills containing specific hormones which prevent ovulation. Foams, jellies or creams placed in vagina prior to intercourse that chemically kill sperms. Sperms ducts are cut and tied to prevent sperms from leaving the ducts. Fallopian tubes are cut and tied to prevent ovum from leaving the tubes. Dome-shaped rubber disk with a flexible rim that covers the cervix so that sperm cannot reach the uterus. A spermicide is applied to the diaphragm before insertion. Injection of specific hormone progestin that inhibits ovulation, prevents sperm from reaching the egg, and prevents the fertilised egg from implanting in the uterus. The sexual reproductive organs of plants. Contain either the stamens (male flowers) or the pistils (female flowers). Contian both the stamens and the pistils. Carriers of the male gametes of the plant. Supports the flower Protect the young flower when it is in the budding stage. Attract animal pollinators through their colour and scent. Recieves pollen grains Connects the stigma to the ovary Protects the ovules. After fertilisation, the ovule develops into a seed. Contains the female gamete (egg cell). After fertilisation, the ovule develops into a seed. Produces male gametes (in pollen grains) Supports the anther The transfer of pollen grains from anthers to stigmas. Transports pollen grains. The transfer of pollen grains from the anther to the stigma of the same flower, or from the anther to the stigma of a different flower in the same plant. The transfer of pollen grains fron the anther of one plant to the stigma of another plant of the same species. To produce offspring with desirable characteristics of each parent.

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CassiaFany © Pollen tube

Sugary secretion on the stigma causes the pollen grain to germinate and producea pollen tube. Micropyle The pollen tube grows down through the style and enters the ovule through a tiny hole calle the microplye. Lies above the hilum. Absorps water for the seed. Fertilisation The fusion of the male gamete in the pollen tube with the female gamete (egg) through a tiny hole called the microplye. Seed A fertilised ovule develops into a seed Fruit The ovary of a fertilised ovule as a whole develops into a fruit. Pericarp The wall of the fruit which develops from the wall of the ovary. Succulent fruits Juicy fruits Testa The protective covering of a seed. Radicle A young root Plumule A young shoot Cortyledons Seed leaves Dicotyledonous seeds Seeds with two cotyledons Monocotyledonous seeds Seeds with one cotyledon. Endosperm Food for the embryo is deposited either inside the cotyledons or the endosperm. Hilum The point where the seed is attached to the ovary wall (on the testa). Pericarp The fruit wall which protects the seeds. Germination The growth of the seed into a seedling. Amylase Breaks down the stored starch to maltose Proteases Break down the protein molecules to amino acids. Maltose and amino acids Diffuse to the embryo which are used to form new cells. Epigeal germination The cotyledons rise above the ground Hypogeal germination The cotyledons remain below the ground. Vegetative reproduction Any method of reproduction in which a specialised or unspecialised part of the parent body separates from the parent and subsequently gives rise to a new individual without involving fusion of gametes. Cutting A commonly used method of vegetative reproduction. Biotechnology The application of biological processes to improve human health and food production. Plant tissue culture The test-tube method of culturing whole plant asexually from very small pieces of tissue cut from the parent plant. Horticulturist An agricultural scientist dedicated to finding better ways to grow, harvest, store, process and ship fruits, vegetables and ornamental plants Growth The permanent and irreversible change in shape, and increase in mass and size aqquired by an organism in the course of its development. Infancy Encompasses the first two years of life. Rapid growth Childhood The period of growth and deveploment, extending from infancy to adolescene. Slower growth Adolescene The stage where a person passes from childhood to a sexually mature adult. It is a period of rapid physical growth and development. Adulthood Starts from about 20 years of age. Early adulthood= the peak of our physical potential. Senescence/ aging Negative growth (a loss in height) because tissues break down more quickly than they can be repaired. Puberty The stage of early adolescence when the secondary sex characteristics become noticeable and the sexual organs become functional.

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CassiaFany © Nutrients Minerals Diet Dietician

Earth’s resources Minerals Natural compounds Copper carbonate Natural elements Oxides Carbonates Sulphides Silicates Hardness of minerals Diamond Geologist Acidified potassium dichromate (VI) solution Metals Malleable Ductile Tarnishing Silicon

Metalloid Silicon compounds Silica

Silicate

Stable compounds

Chemical substances which organisms need for releasing energy, for warmth, for growth and repair, and to carry out all life processes. Essential substances which are required to regulate the metabolism of the body. The food we eat. Works in hospitals, institutions, schools, restaurants and hotels. They help in planning menus. They may act as food counsellors. A dietician advises individuals on how to plan their melas so that their diets contain proper nutritional value. Materials found in nature that are useful or necessary to living things. Elements or compounds which occur naturally in the Earth’s crust. Formed when elements combine chemically. A mineral formed from the combination of oxygen, carbon and copper. Pure carbon such as gold, silver ad diamonds. The chemical combination of oxygen and metals. Metal + oxygen = Metal oxide Compounds that contain oxygen, carbon and metals Metal + oxygen + carbon = Metal carbonate Formed from the combination of metals and sulphides. Metal + sulfur = Metal sulphide Formed when metals combine with oxygen and silicon chemically. Metal + silicon + oxygen = metal silicate The ability of minerals to resist being scratched. The hardest mineral. Mined for their beauty. A scientist who studies the Earth, including its origin and history and the way the rocks and soil have changed since the Earth was formed. Used to identify the prescence of sulphur dioxide gas. Orange potassium dichromate (VI) solution –green. Extracted from the minerals ores found within the Earth’s crust. Can be hammered into various shapes Can be drawn into wires Most metals combine with oxygen in the air to form a surface film of metal oxide. This reaction is called tarnishing. An element, a metalloid, a shiny, blusih-gray, brittle metalloid with a high melting point. Does not occur freely in nature. One of the most abundant elements in the Earth’s crust. An element with both the metal and non-metal properties Formed when silicon combines with other elements. Natural silicon compounds: Silica and silicate Is formed when silicon combines chemically with oxygen. Stable compounds Quarts, flint, and sand. Formed when silicon combines chemically with oxygen and metal. Stable compounds. Abestos, mica, talc and clay. Do not dissolve in water, do not react with acids and are able to withstand heat. Will remain in the Earth’s crust for a long time.

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CassiaFany © Calcium

A reactive metal. It does not exist in its pure form in nature. Tends to combine with other elements to form compounds. Calcium carbonate A compound of calcium, oxygen and carbon. Fairly stable compound. Only dissolves in slightly acidic water. (form salt, carbon dioxide and water) Calcium carbonate + hydrochloric acid = calcium chloride + CO⑵+ H(2)O Stalagmites, stalactites, seashells, eggshells, coral reefs and bones. Limestone A sedimentary rock which is formed from the remains of sea creatures and fragments of shells settled at the bottom of the sea. Quicklime (calcium oxide) Is formed when calcium carbonate is heated strongly. It decomposes and changes into calcium oxide (quicklime) and carbon dioside. Calcium carbonate – (heated strongly)→ calcium oxide (quicklime) + carbon ioxide Slaked lime (carbon Is formed when calcium oxide (quicklime) reacts with water. Heat is hydroxide) produced in the process. Calcium oxide (quicklime) + water → calcium hydroxide (slaked lime) +heat An alkali Lime water Calcium hydroxide (an alkali) dissolves in water to become lime water which is used to test for the presence of carbon dioxide. Calcium hydroxide solution (lime water) + carbon dioxide → calcium carbonate (white precipitate) + water Fuels Substances that burn to produce heat as a form of energy. Fossil fuels Natural fuel rewsources Petroleum, coal and natural gas= formed from the remains of living plants and animals that lived millions of years ago. The formation of coal Dead plant minerals covered by mud and sand in swamps. High pressure and heat act on the partially decayed plant material. Over a long period of time, a black solid called coal is formed. Coal A mixture of carbon, hydrocarbons and other compounds. When coal burns, the main products are carbon dioxide and water. The formation of Petroleum (crude oil) and natural gas are formed from the remains of petroleum and natural tiny sea creatures which were buried in sediments at the bottom of the gas ocean. As these remains decompose slowly, they were subjected to great heat and pressure. Over millions of years, these remains were changed into a dark, sticky liquid called petroleum. Some may change into gas, called natural gas. Petroleum and natural gas are found together, held in between layers of non-porous rocks. Petroleum A dark, sticky and foul-smelling liquid. A mixture of hydrocarbons. Must be separated into fractions before it can be used. Refining The separation of petroleum into useful fractions is calle the refining of the oil. Fractional distillation Petroleum can be refined to useful fractions through fractional distillaiton because each fraction has a different boiling point. Furnance= 400°C, bitumen= (>350°C), fuel oil= (300-350°C), lubricating oil=( 250-300°C), diesel=( 230-250°C), Kerosene= (150-230°C), naphtha= (75-150°C ) , petrol= (40-75°C), petroleum gas= (