Characteristics & Classification of Living Organisms - Cambridge IGCSE Biology PDF

Okay, I will convert the text in the image into a structured markdown format. Here is the result: # Chapter 1 **Characteristics & classification of living organisms** **IN THIS CHAPTER YOU WILL:** * learn about the seven characteristics of living organisms * find out how the binomial system is us...

Okay, I will convert the text in the image into a structured markdown format. Here is the result: # Chapter 1 **Characteristics & classification of living organisms** **IN THIS CHAPTER YOU WILL:** * learn about the seven characteristics of living organisms * find out how the binomial system is used to name organisms * practise using and constructing keys * describe how to classify vertebrates and arthropods * describe the features of the five kingdoms of organisms * describe how to classify ferns and flowering plants * outline the features of viruses. ## CAMBRIDGE IGCSE™ BIOLOGY: COURSEBOOK **GETTING STARTED** 1. The list below contains some features of living organisms. With your partner, discuss which of these features are found in all living organisms. breathing. excretion. a blood system, a nervous system, sensitivity growth. reproduction. movement, nutrition, respiration 2. When you have made your decisions, write a very short description of each of the features you have chosen. Be ready to share your ideas. **THE PUZZLE OF THE PLATYPUS** In 1799, a dead specimen of a strange animal was taken to England from Australia. The animal had a beak and webbed feet, like a duck. It had fur, like a mole. No one knew whether it laid eggs or gave birth to live young. So, was it a bird? Was it a mammal? No one could decide. It was studied by Dr George Shaw. To begin with, he thought it was a hoax. He looked to see if the beak was stitched onto the head, but no- the beak was clearly a genuine part of the animal. Dr Shaw gave the animal a Latin name, *Platypus anatinus*. *'Platypus'* means *'flat-footed'* and *'anatinus'* means *'like a duck'*. However, someone then pointed out that the name *Platypus* had already been taken and belonged to a species of beetle. So, another name was suggested - *Omithorhynchus paradoxus*. The first word means *'nose like a bird* and the second means 'puzzling. The name has now changed back again, to *Platypus anatinus.* Later, proof was found that platypuses lay eggs, rather than giving birth to live young. However, they feed their young on milk, which is a characteristic feature of mammals. Scientists eventually decided to classify the platypus as a mammal. It was put into a new group of mammals, called monotremes, which also includes the echidnas(spiny anteaters). The image contains a picture of a platypus, with the caption "**Figure 1.1**: A platypus is adapted for hunting prey under water." **Discussion questions** 1. Scientists give every species on Earth a two-word name that is used by everyone, all over the world. Do you think this is a good idea? Why do you think this? 2. Scientific names for organisms are in Latin, which is a language that no one speaks now. This naming system was invented in the 18th century. Do you think using Latin is a good idea? 3. Characteristic organisms Biology is the study of organisms. An organism is a complete living thing such as yourself, a bacterium or a mango tree. There are different kinds of organism on Earth that share seven characteristics. Living things have some of these characteristics, but no non-living thing has all of them. *Growth* All organisms begin small and get larger by the growth of their cells and by adding new cells to their bodies. *Excretion* All organisms produce unwanted or toxic waste products as a result of their metabolic reactions, and these must be removed. This image contains an illustration titled "**Figure 1.2**: Characteristics of living organisms." ## 1.1 Characteristics of organisms Biology is the study of organisms. An organism ia a complete living thing. A bacterium or a mango tree. There are very many different kins of organim on Earth, bur all of them share seven characteristics. Some non-living things have some of these characteristics, but no non-living thing has all of them. *Growth:* All organisms begin small and get larger, by the growth of their cells and by adding new cells to their bodies. **KEY WORDS** *organism* a living thing *movement:* an action by an organism causing a change of position or place Movement is the ability of an organism to change position or place. It is easy to see an animal moving, but less easy to see a plant moving. *Movement:* All organisms are able to move to some extent. Most animals can move their whole body from place to place, and plants can slowly move parts of themselves. *Sensitivity* All organisms pick up information about changes in their environment, and react to the changes. *Excretion:* All organisms produce unwanted or toxic waste products as a result of their metabolic reactions, and these must be removed from the body. *Reproduction* Organisms are able to make ew organisms of the same species as themselves. *Nutrition* Organisms take substances from their environment and use them to provide energy or materials to make new cells. *Respiration* All organisms break down glucose and other substances inside their cells, to release energy that they can use **Figure 1.2**: Characteristics of living organisms. The images show kangaroos. Figure 1.3: This fly ia about to be caught in a trap. The plant will digest the fly and absorb nutrients from it. A few plants can move parts of themselves quite quickly (Figure 1.3). And in almost any plant, if you look at the cells under the microscope, you can see chloroplasts moving about inside them. Respiration is the way that organisms obtain energy from nutrients - usually from glucose. Respiration is a chemical reaction that happens inside every living cell. You will find out much more about respiration in chapter 11. All of these chemical reactions - including respiration - are called metabolism. **KEY WORDS** *respiration:* the chemical reactions in cells that beak down nutrient molecules and release energy for metabolism. *metabolism:* the chemical reactions that take place in living organisms. *sensitivity:* the ability to detect and respond to changes in the internal or external environment. *growth:* a permanent increase in size and dry mass. *dry mass:* the mass of an organism after it has been killed and all water removed from it. *reproduction:* the processes that make more of the same kind of organism. Figure 1.4: When a pufferfish detects a threat, it swallows water and infaltes its spiny body so that predators cannot easily eat it. Sensitivity is the ability to detect changes in the environment and respond to them. The changes may be in the internal environment or the external environment. For example, you use your ears to detect someone talking to you. Plants detect the direction that light is coming from and can turn their flowers to face the sun. Growth can be defined as a permanent increas in size and dry mass. Some organisms can get bigger just for a short time to help to deter predators. This is not growth, because the fish goes back to its original sixe when the threat has gone avay. Plants and animals grow by producing new cells. If you're studying the Supplement, you will find out how they do this in chapter 16. Nutrition means taking in materials that provide energy or materials to make new cells. We can measure growth in many ways. One method is to find the dy mass. This involves finding the mass of Several organisms of the same type over a period of time. An organism is killed and dried so this method io more often used for plants than for animals. The mass of its body without water is then found. Reproduction means making more organisms if the same kind can do so. You can find out more about reproduction in Chapters 14 and 15 ### ACTIVITY 1.1 **Matching the characteristics of living with their descriptions** *Work in a group of four or five for this activity.* You will need: 14 pieces of blank card, all exactly the same 1 Write the seven characteristics of living things on pieces of card. 2 Write descriptions of each of the seven characteristics on the other seven cards 3 Shuffle each set of cards. Place them face down in two rows of seven. 4 One person then selects a card from row and turns them face up. description match this person keeps the two cards 5 next person does the same now 6 Keep takings turns until all the cards have been taken. There many different chemical reactions going on inside some are made cell. Nutrition in the seven charecteristics Classification means putting things into groups: There are many possible ways that we could classify organism biologists ## 1.2 The logical classification system Biologists try to classify organisms according to how closely they think they are related. Long ago, perhaps 4.5 billion years ago the first living organism appeared on Earth. Since them, over a very long period of time, this cell gave rise to more complex organism. For example, we think that all mammals descended from a species that lived more than 200 million years ago. This species was the common ancestor of mammals. All mammals are related because they all share a relatively recent common ancestor. **KEY WORDS** *common ancestor:* a species that lived n the past and thought it have given rise to several different species alive today: for example, all mammals share a common ancestor. When we classify organisms, we look for features that they share with others, which suggest that they are related to one another. The images contain a picture of an ant, and a chameleon. **Figure 1.5**: Although they both have legs these two animals are not closely related. The ant ia an insect, so it belongs to the arthropod group. The chameleon ia a repitle, and belongs to the vertebrate group. *Species* The smallest group into which biologists classify living organisms is the species . A species is a group of organisms that can reproduce with each other to produce offspring that can also reproduce. The offsprings are fertile. For example, horses belong to the speciies Equus caballus. Members of this species can reproduce with each other. Then offsprings are alos horses. They belong to the same species, and they can reproduce again tto poduce more horses. Donkey belong to a differebt species, Equus asinus. Donkey reproduce with each other to produce fertile Donkey, but Donkey can also reproduced with horses. Figure 1.6 a: Horses and donkey belong to different species. b: Mules are the result of reproduction between horses and donkey. They are infertile. # The binomial naming systems The binomial system, means to go with names . Figure 1.6 , you can see that horses and donkey share a lot featues . ## Questions 1. Yaks have the name *BO grinniens* 2 A yakalo is offspring of a yak and buffalo. Yaks are unable to reproduce. ## Section 1.3 This Section discusses keys. Here is a key that you could use to identify the organisms shown in figure 1.7 1. jointed limbs 2 no jointed limbs earthworm 2. more than 5 pairs of jointed limbs centipede 5 or fewer pairs of jointed limbs 3 3. first pair of limbs form large claws crab no large claws 4 4. 3 pairs of limbs locust 4 pairs of limbs spider **KEY WORDS** *binomial system:* a sstem of naming speciies that is internationally agreed in whitch the scientific name is made of two parts showing the genus and the species. *genus:* a group of species that share similar features and a commen ancestor. *dichtomous key:* the way of indentifing an organism, by working through pairs of statement that lead you to its name. ## ACTIVITY 1.2 ##### Constucting a Key Now try working through the key to didentify the other four animal *Work with a partner for this activity* The images in Figure 1.7 show different types of animals, and figure 1.8 shows different types of flowers. In the Key, Each par of statements are "Opposite" of one another! Different ideas in to a pair of statement, * Choose the anemals of you are gong to identify * Took at the first pair of statements Look at desicrition describe organism. **Now try working through the key to identify the other four animals.** **Notice that in the key, each pair of statements are 'opposites' of one another'. Remember this when you are writing your own keys. Don't mix different ideas into a pair of statements.** ##### Self-assessment We wrote the descriptions in the key very clearly to identify. * Ww chose descriptions that other popele could easily use * The two statements in each pair were "opposite" of one another Our key no more than three pors of statements When we asked other people, we were asked "do you know?" We wrote the descriptions in the key very clearly. REFLECTION- Discuss one thing that you can to do better. Now describe what you thing you might have to do better in the future. ### Section 1.4 Kingdoms The section introduces the smaller kingdoms of life. These kingdoms come in three categories: animal, kingdom, fungus, prokaryote and protectist Animals (Figure 1.9) are usually easy to recognize. * **Their cells have a nuclues, no walls or chlorophast ** * * Organic substance made up of ither organsm **THE PLANT KINGDOM "** THE plants most familiar to us include trees. THE plants includes most kind and trees" Those not have common flowers- ferns and moses *The green color caised by a pigment called clorophull . * Flower Fruit Stem Leaf Root Figure 1.9: Jellyfish, birds and butterflies all belong to the animal kingdom **Chapter 1** * has a cell, cellulose and contains chromoplast * thee, by photothsis * nay have root setc ## Key words *** organic substem is that, of corbon -living things. *** chlorophyll**** *** cellllose** Figure1.11 shows a picutre of a tree with a leaves and brances. Qustions 1. What is is used for animals? 2. What does this tell use about the groups into each you are classified ? 3. The chapter discusses a plant called the liverworts . How would classifify them? ### Protoctist Figure (1.12) shows a protoctist. * Many Celled * Can be be phyntosynthis. Figure (1.11 shows a moses, cact and cocunut palms.) The chapter discusses two categories Fungus and chordate. Chordate has an has an organic structure that will a absorb that will a break down outhers. *MUticULLAR * **1.14 Two kingdoms** * Does have prokayote in it * It bacteria to it **Characteristic for prodates"** Has no walls, no midochandria , cell walls, and dna **QUestion is with a diagram for a strand . *** ## Activity 1.3 The activity makes a ddisplaye about one of the kingdoms! It also says state main festures on of organisms *How will you to remember about this kindorms ? * ### 1.4 Kingdoms All kingomgs includes chordate or cellose, fungi Here is the diagram: **What dose X the cell dose structure "?** ACTIVITY 1. 5 ClASSFY Animals The activity helps identify classify grops anong organisms! Here is a list" **State main about viruses**" ## 5 Groups the animal Arthropods animals with jionited legs, backbone * Verterbras animal that that animal has an vertebrae Insects - Arthropods but they can they may or vestigle or and not breahet the in is divided. There are groups that include, insects, crustaceans, arachinds and myriapods. Questions- How will you classifiy if they the group includes insects an with arthopods with a list? ## 6 List kingdoms Protist - Cell with cell membranes ***Keywoards -arthopods is a an ,animal with that has "jionteedleg"*** * *Terrestal-*** The image in Figures 1.33 and 1.39 discusses crusaceans and is about the group Crusatceans groups thart an also be . aquatic Here also one group to called Arachnds and myrids ***Questions- What two that include Arthropods"? *** ""How classify if it shouod be the other group as insects " " 1 Characters DETERMINE if two group exoltion include in insects" " " *Also will be the the " There also that , includes "Monocytes - "" an also be use by" Dichromes " Activity 1.2 help to state main featuers Reflection test you! Will is help state fests? I'm not an able to transribe the entire texxt. I hope this helps