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Biology : Chapter 1 : The Science of Life
- 1. Name : Class : Date: • What is Biology? • Characteristics of Life • Classification of Living Organisms Chapter 1 The Science of Life
- 3. Overview and LearningOutcome 1.1 : What is Biology 1.2 : Characteristics of Life 1.3 : Classifying Living Organisms Definition of biology, biologist and organisms State the characteristics of life Understand why biologists classify organisms State how biologists classify organisms
- 4. The word ‘biology’comes from the Greek term bios, which means life The Greek term logos means knowledge Scientists who study living things are called biologists Biologists use the term ‘organisms’ to refer to a living thing Biology is the science of life. It involves the study of living things and the theories that describe the world of life 1.1 : What is Biology?
- 7. 1.1 : KeyIdeas 1. The study of science of life is called biology 2. Biologists are scientists who study living things 3. Organism is the term used to refer to a living thing
- 8. It is noteasy to give an exact definition of the term ‘life’ However, observations and experimentations have shown that all living organisms carry out certain activities We say these activities are characteristics of living organisms, or in other words, these activities are the 1.2 : Characteristics of Life
- 9. Cells Nutrition Respiration Excretion Growth and Development Movement Reproduction Sensitivity Adaptibility 1.2 : Characteristics of Life
- 10. All organisms aremade of simple units called cells The cells of an organism carry out activities necessary for the organism to stay alive We will be learning more about cells in Chapter 2 *** Non-living things are not made up of cells ; they are made up of atoms Cells The cell (from Latin cella, meaning "small room") is the basic structural, functional, and biological unit of all known living organisms. Cells are the smallest unit of life that can replicate independently, and are often called the "building blocks of life".
- 11. All organisms needenergy to stay alive They also need materials to make the living matter in the cells of their bodies Nutrition is the process by which organisms take in food and convert it into new protoplasm Organisms gain the energy and materials they need from their food Nutrition
- 13. Living organismsrequire energy to perform activities such as growing and moving Living organisms gain energy through the process of respiration Respiration is the oxidation of food substances to release energy for cell activities All organisms respire In both plants and animals, organic food substances such as carbohydrates and fats are used to store energy This energy is set free when these substances are broken down through respiration into carbon dioxide and water Respiration
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- 16. A chemical reactiontakes place when glucose is broken down during respiration Numerous other chemical reactions occur in the cells of a living organism Since these chemical reactions take place in living cells, they are called metabolic reactions. Metabolism is the sum of all the biochemical reactions that take place within the cell Excretion
- 17. Some metabolicreactions produce waste substances that are useless or even harmful to the organism These substances must be removed The process by which the organism removes metabolic waste products is called excretion The substances that are to be removed are called excretory products Carbon dioxide, water, mineral salts and nitrogenous waste are all excretory products Excretion
- 18. Most animals havespecial organs for removing their excretory products Living organisms are open systems continually receiving and disposing both energy and materials – this process is basic to their continued existence. If it stops or breaks down, the organism dies Excretion
- 19. Disposal ofliquid waste from human body is done by the excretory system. The system consisting of two kidneys, two ureters, one urinary bladder, and one urethra performs the work of collecting, storing and removing all the liquid waste products from the body. Kidney Diseases Ureteral Diseases Urinary Bladder Diseases Urethral Diseases Diseases Related to the Excretory System
- 20. Growth is apermanent increase in the mass and volume of an organism when absorbed food is converted into living matter Some of the new matter formed is used to repair worn out parts of the cell The rest is added to the original living matter and this increases its size Growth and Development
- 21. Development may makean organism more complex or even change its form The body of an organism can change and become larger in size It can also become more complex This kind of growth is characteristic of living organisms Growth and Development
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- 23. Movement is acharacteristic of organisms The movement of organisms is independent of external forces Most animals are able to move from place to another Such motion is called locomotion Some animals do not have the power of locomotion, however, they can still move parts of their bodies Most plants are unable to carry out locomotion but parts of the plants are always moving slowly Movement
- 24. Self-powered motion bywhich a whole organism changes its location through walking, running, jumping, cra wling, swimming or flying. Locomotion does not include actions that are not powered by the organism, for example, drifting Locomotion
- 25. All living organismsare able to reproduce In reproduction, some characteristics are passed on from the parents to their offspring This is because genetic information is passed on from the parents to their offspring Organisms are mortal, thus reproduction is necessary for a species to survive Reproduction
- 26. Animals andplants are sensitive to changes in their environment They can detect and react to these changes in ways which are beneficial to them A change in the environment or an external influence causes the organisms to react in a predictable way Such a change or external influence is called stimulus The reaction of an organism to a stimulus is known as a response This response of living organisms to a stimulus is termed sensitivity or irritability Sensitivity
- 27. Living organismsare able to adjust and adapt to changes in their environment Adaptation is any characteristic of an organism that improves its chances of surviving in its environment Can be classified into structural adaptation or behavioural adaptation or physiological adaptation Adaptability
- 28. Anatomical adaptationsare physical features such as an animals shape. Behavioural adaptations can be inherited or learnt and include tool use, language and swarming behaviour. Physiological adaptations include the ability to make venom; but also more general functions such as temperature regulation. Eg : Adaptations to surviving in extreme conditions : Anatomical (Structural) : Grow thicker fur (cold climates) Behavioural : To come out only at night to avoid high temperatures (hot climates) Physiological : Temperature Regulation Learn More About : Adaptability Read more about adaptability at http://www.bbc.co.uk/nature/adaptations
- 29. Some ofthe characteristics of living organisms can be found in certain non-living matter For example, a motorcar can move and give off waste products when its fuel is burnt It also has a well-organised and complex structure However, machines do not reproduce and they do not grow All the characteristics of life must be considered when distinguishing between a living organism and a non-living matter Understanding the differences between a living organism and a non-living matter
- 30. 1.2 : Characteristicsof Life (Summary) Cells - Building blocks of life Nutrition - Process by which organisms take in food and convert it into new protoplasm Respiration - Oxidation of food substances to release energy for cell activities Excretion - Process by which organisms remove metabolic wastes products Growth and Development - Permanent increase in the mass and volume of an organism when absorbed food is converted into living matter - - Make an organism more complex and even change its form Movement - Movement of organisms is independent of external forces Reproduction - Process which is necessary for a species to survive Sensitivity - Response of living organisms to a stimulus Adaptability - Process by which organisms adjust and adapt to changes in their environment
- 31. • The characteristicsof life are as follows 1. Organisms are made up of cells 2. Organisms gain energy and the materials needed to make the living matter for their bodies, through the process of nutrition 3. Organisms respire. Respiration releases energy through breakdown of food substances such as glucose 4. Organisms remove metabolic waste products through excretion 5. Organisms grow. The growth of an organism is a permanent increase in the mass and volume of the organism 6. Organisms can move by themselves in a directed and controlled way 7. Organisms reproduce their own kind 8. Organisms are able to detect and respond to changes in their environment. This is called sensitivity 9. Organisms adapt to increase their chances of survival • All the characteristics of life must be considered when distinguishing between a living organism and non-living matter 1.2 : Key Ideas
- 32. There are millionsof living organisms on Earth. In order to study them, biologists group living organisms according to their similarities and differences This is called classification The system of classification used today was developed by the Swedish naturalist, Carolus Linnaeus 1.3 : Classifying Living Organisms
- 33. Swedish botanist,physician, and zoologist, who laid the foundations for the modern biological naming scheme of binomial nomenclature (formal system of naming species of living things by giving each a name composed of two parts) For example, homo sapiens is the scientific term for humans Homo is the genus Sapiens is the species Carolus Linnaeus
- 34. What systemscould be used to classify organisms? Organisms can be grouped according to properties that are meaningful to humans This type of classification is called artificial classification However, this type of classification is not useful to biologists, as it does not show any natural relationships between the organisms in a group Biologists use a system of classification called natural (biological) system of classification Such a system is based on similarities and differences between organisms This system is easy to refer to when identifying organisms Classifying Living Organisms
- 35. Biological System ofClassification
- 36. In a naturalsystem classification, organisms are classified according to a graded scale or hierarchy The resemblance between organisms becomes much closer as we go down the scale of classification For instance, it is easy to distinguish one family from another It is also fairly easy to separate different genera but different species may be more difficult to differentiate Biological System of Classification
- 37. Kingdoms of LivingOrganisms
- 38. The commonname given to an organism may vary in different parts of the world This can cause confusion Carolus Linnaeus used Latin to give 2 names to each organism This naming system is called the binomial system The 1st name refers to the genus which the organism belongs and it starts with a capital letter The 2nd name is the species name and it starts with a small letter Both genus and species names are italicised or underlined Binomial System of Naming Species
- 39. For example,domestic cat First Name : (genus) : Felis Second Name : (species) : domestica Therefore, its scientific name is Felis domestica Binominal System of Naming Species
- 40. We classify organismsaccording to their similarities and differences The natural classification is hierarchical, with each level in the hierarchy having a specific label Starting from the largest group, the order is as follows : Kingdom > Phylum > Class > Order > Family > Genus > Species 1.3 : Key Ideas
- 41. All living organismsare capable of 1. Excretion and Respiration 2. Locomotion and Excretion 3. Photosynthesis and Reproduction 4. Respiration and Locomotion Test Yourself!
- 42. All living organismsare capable of 1. Excretion and Respiration 2. Locomotion and Excretion 3. Photosynthesis and Reproduction 4. Respiration and Locomotion Test Yourself! Ans : 1
- 43. Below is alist of groups Carolus Linnaeus used to classify organisms Rearrange the groups in an hierarchy, beginning with the largest group Test Yourself! Order Genus Kingdom Class Phylum Family Species
- 44. Answer : Kingdom >Phylum > Class > Order > Family > Genus > Species Test Yourself!
- 45. We will learnabout cells in the next chapter Remember to read about cells so as to speed up the teaching and understanding process! Next Chapter