Keep it Simple Science Living Cells PDF Years 7-8

PO Box 2575 ® PORT MACQUARIE NSW 2444 (02) 6583 4333 FAX (02) 6583 9467 keep it simple science www.keepitsimplescience.com.au ABN 54...

PO Box 2575 ® PORT MACQUARIE NSW 2444 (02) 6583 4333 FAX (02) 6583 9467 keep it simple science www.keepitsimplescience.com.au ABN 54 406 994 557 [email protected] keep it simple science Photocopy Master Sheets Years 7-8 Living Cells Disk filename = “06.Cells” Copying is permitted according to the Site Licence Conditions only  Site Licence Conditions You may use the disk contents to make A.V. Our product is supplied on CD displays, such as by using data projectors or You may copy the CD for back-up only. overhead projectors, at one school and campus only. You may store the CD contents in data retrieval systems to facilitate printing of hard Students may view the file contents on school copies at one school and campus only. computer networks, but you MAY NOT supply copies of the CD to students nor allow them to You may print unlimited copies and/or make obtain copies of the files by email, download or unlimited photocopies: other methods. - at one school and campus only, - for use by students enrolled (i.e. Students may only receive the product in at that school and campus only, Hard Copy Format, or view AV or network - for non-profit, educational use only. displays.) Please Respect Our Rights Under Copyright Law keep it simple science Photocopy Master Sheets Topics Available Year 7-8 General Science Year 9-10 General Science Disk Filename Topic Name Disk Filename Topic Name 01.Energy Energy 12.Waves Wave Energy (inc. Light) 02.Forces Forces 13.Motion Forces & Motion 03.Matter Solids, Liquids & Gases 14.Electricity Electricity 04.Mixtures Separating Mixtures 15.Atoms Atoms & Elements 05.Elements Elements & Compounds 16.Reactions Compounds & Reactions 06.Cells Living Cells 17.DNA Cell Division & DNA 07.Life Living Things 18.Evolution Evolution of Life 08.LifeSystems Plant & Animal Systems 19.Health Health & Reproduction 09.Astronomy Astronomy 20.Universe The Universe 10.Earth The Earth 21.EarthScience Earth Science 11.Ecosystems Ecosystems 22.Resources Resources & Technology Year 11-12 Science Courses Biology Chemistry Earth & Envir. Physics Science Preliminary Core Preliminary Core Preliminary Core Local Ecosystem Chemical Earth Preliminary Core World Communicates Patterns in Nature Metals Planet Earth... Electrical Energy... Life on Earth Water Local Environment Moving About Evolution Aust. Biota Energy Water Issues Cosmic Engine HSC Core HSC Core Dynamic Earth HSC Core Maintain. a Balance Production of Materials HSC Core Space Blueprint of Life Acidic Environment Tectonic Impacts Motors & Generators Search for Better Health Chem.Monit.&Mngment Environs thru Time Ideas to Implementation Options Options Caring for the Country Options Communication Shipwrecks, Corrosion... Option Quanta to Quarks Genetics:Code Broken? Industrial Chemistry Introduced Species Astrophysics 2  ® keep it simple science Copying is permitted according to the Site Licence Conditions only “Mind-Map” Outline of Topic This topic belongs to the branch of Science called “Biology”, the study of living things. Biology has many aspects, from studying the variety of life forms and how they evolved over the history of the Earth, to their body structures and functions, to how they feed, grow and reproduce. Movement of Substances through Parts of a the Membrane Cell Cells. Structure & Function Unicellular & Multicellular Living Cells Micro-organisms Types of Microbes Beneficial & Harmful Mitosis: Microbes Cell Division How a Knowledge of Microbes has Changed Society Years 7-8 Topic 6 Living Cells 3 copyright © 2008 keep it simple science www.keepitsimplescience.com.au  ® keep it simple science Copying is permitted according to the Site Licence Conditions only Make your own “Mind-Map” TITLE PAGE. Cut out the boxes. Sort them into an appropriate lay-out on a page of your workbook, then glue them down. Add connecting arrows and colour in. How a Knowledge of Parts of a Living Microbes has Changed Cell Cells Society Beneficial Movement of Cells. Substances through & Harmful Structure & Function the Membrane Microbes Mitosis: Unicellular Types of Cell Division & Microbes Multicellular Micro-organisms Make your own “Mind-Map” TITLE PAGE. Cut out the boxes. Sort them into an appropriate lay-out on a page of your workbook, then glue them down. Add connecting arrows and colour in. How a Knowledge of Parts of a Living Microbes has Changed Cell Cells Society Beneficial Movement of Cells. Substances through & Harmful Structure & Function the Membrane Microbes Mitosis: Unicellular Types of Cell Division & Microbes Multicellular Micro-organisms Years 7-8 Topic 6 Living Cells 4 copyright © 2008 keep it simple science www.keepitsimplescience.com.au  ® keep it simple science Copying is permitted according to the Site Licence Conditions only Cells - the Units of Life All Living Things are Made of Cells How Big is a Cell? Every living organism that has ever been Obviously, cells are very small and you need examined with a microscope has been a microscope to see them. found to be made up of tiny little “bags” of living matter that we call “cells”. Cells vary a lot in their shape and size. In the diagrams below, the vertical scale bar Each cell is alive. Some living things are represents 0.1mm (1/10 of a millimeter). made up of just one cell. All the familiar living things are made up of many, many cells. Your body contains at least 200 billion cells. (200,000,000,000 cells) This represents a very large cell. DIAGRAM OF A LIVING CELL Various structures called “organelles” are visible inside a cell. 0.1 mm Some cells in your blood are about this size. Some cells are a very odd shape, like this. The cell is filled with a jelly-llike “Cell Membrane” on liquid called Some cells are so small that the outside contains “cytoplasm”. even with a good microscope, the cell , and controls they are hard to see in detail. what goes in or out. A Little History The Discovery of Cells He saw that the cork was made up of By about the1500’s, people had begun rows and rows of hollow little boxes, using glass lenses to make spectacles like rows of small rooms in a gaol or and “magnifying glasses”. Soon, the monastery. He described them as telescope was invented, and later some “cells” and the name experimenting was done to construct stuck. What Hooke saw microscopes to look at very small things. Hooke’s We now microscope understand that In 1665, Robert these cells were Hooke, an English hollow because scientist, used a cork is the dead Small hollow “rooms” primitive microscope bark of a tree. within a piece of cork. to look at a piece of cork. The hollow spaces were where the living cells used to be when the bark was growing. Years 7-8 Topic 6 Living Cells 5 copyright © 2008 keep it simple science www.keepitsimplescience.com.au  ® keep it simple science Copying is permitted according to the Site Licence Conditions only Parts of a Cell Each living cell is a very complicated structure. Some of the most important parts are described below. Essential learning! Animal Cells There is probably Cytoplasm no actual cell The diagram shows the main features of a typical cell in an which looks just fills the cell animal. like this one. Real shapes Nucleus vary greatly. Nucleus This organelle is the “control centre” of the cell. The nucleus sends out “chemical messengers” to every part of the cell, to control all the cell processes. Cytoplasm Various structures This a jelly-like liquid which completely fills called the cell. It is mostly water, with thousands “organelles” (little organs) have special of different kinds of chemicals dissolved in it. Cell functions within each cell. Also suspended in the cytoplasm are many Membrane The nucleus is the most small structures called “organelles”. important organelle. Many chemical reactions are constantly occurring in the cytoplasm solution, and within the organelles. “Life” is mostly a matter of chemistry. Cell Membrane Surrounding the cell, and containing it, is an extremely thin, flexible layer. This membrane not only holds all the cell parts together to form a little bag of life, but it controls all the chemicals which enter or leave a cell. Plant Cells Plant cells have all the same features of animal cells, but have 2 extra features that you need to know about. These are never present in an animal. Cytoplasm Cell Nucleus Membrane Chloroplasts These are green-coloured organelles which absorb the energy of the Sun and use it to make food for the plant by the process of photosynthesis. Not every plant cell has chloroplasts; only the leaves and sometimes the green stem. Cell Wall This is a tough, fibrous, non-living layer on the outside of the cell. It makes plant cells stronger and helps to maintain the stiffness and shape of thin leaves, petals and Cell Wall Chloroplasts on the outside of the which absorb light and fragile roots. cell membrane make food for the plant Years 7-8 Topic 6 Living Cells 6 copyright © 2008 keep it simple science www.keepitsimplescience.com.au  ® keep it simple science Copying is permitted according to the Site Licence Conditions only Movement of Substances Through the Cell Membrane Water What Cells Need Oxygen Food Each cell is alive. This means it has all the requirements that you have. To stay alive you need to breathe, eat and drink, and so does a cell. Food chemicals and water must get in. Oxygen gas (O2) must get in. Waste products must get out. Carbon Dioxide & other wastes “Wastes” include the gas carbon dioxide (CO2), plus other waste chemicals from The cell membrane is a bit like using a processing food. plant hedge as the fence around a farmyard. A hedge will prevent the cows For these substances to get in or out, getting through, but a mouse or lizard will they must move through easily crawl and wriggle through. the cell membrane. Similarly, the cell membrane acts as a The cell membrane does not have a barrier to large chemicals and organelles, “mouth” or any openings, so how is this but small molecules (like water, O2 & CO2) possible? can easily pass through. The word “permeable” describes something that liquids can seep or soak through. The cell membrane is “semi-permeable” which means that some substances can move through it, but other things cannot. Why the chemicals move is another matter. You may have already studied “diffusion” in a previous topic. Diffusion is revised below. Diffusion Fluids (liquids and gases) seem to be able Gas Jar of air to mix themselves together automatically. When the glass separator is one drop of separator removed, the food colour two gases mix dye The food colour themselves spreads out through Gas Jar together. the water by itself. of Water brown Without any stirring, gas it auto-m mixes through the water. The explanation is in the Moving-Particle Model of matter. In liquids and gases, the particles are moving around. If 2 different This process is called “Diffusion”. gases or liquids are side-by-side, then the moving particles will automatically mix. The coloured solution can mix itself through the beaker of water. The brown Some substances move through the cell gas can mix with the air without any help. membrane because of diffusion. Years 7-8 Topic 6 Living Cells 7 copyright © 2008 keep it simple science www.keepitsimplescience.com.au  ® keep it simple science Copying is permitted according to the Site Licence Conditions only Worksheet 1 Cells Student Name............................................. Fill in the blanks the j).................................................., which Every living thing is made of a)................ Each surrounds the cell. It also controls one is alive. To see cells you need to use a k).................................................. of the cell. b)...................................... Plant cells have 2 additional features: Some living things are composed entirely of a tough l)................................. on the outside of c)................ cell, but all familiar life-forms are the cell membrane. made up of d)................................ of them. Cells m)................................, which absorb are generally less than e)................... (fraction) n)......................... energy to make food by the of a millimetre in size, and many are much process of o)......................................... smaller still. Each cell needs to get food and Cells were first seen (and named) by p).......................... (gas) in, and to remove f).......................................... in 1665 wastes such as q)............................... (gas) These must all move through the The main parts of a cell are: r).................................................. which can let the g)...................................., which is the some things through, while blocking others. control centre for each cell. It is said to be “s)...............-...................................”. h)........................................, a jelly-like liquid Small molecules like water can easily move which fills the cell. In it are also many small through by the process of structures called i)..................................... t)...................................... Worksheet 2 Cell Structure & Function Student Name............................................. Match the lists. 7. Process by which small Write the letter (A,B,C, etc) of the list molecules can move through.............. item which matches each description. a membrane. Descriptions List Item 8. A gas which cells need to get in from the outside............... 1. Magnifying device used to view cells............... 9. What cytoplasm is mostly made from............... 2. Man who first saw cells............... 10. Found on the outside of 3. Part of a plant cell which is plant cells only............... green and makes food............... List Items (not all will be used) 4. Organelle which controls A. water G. chloroplast all cell functions............... B. A.Einstein H. semi-permeable C. cytoplasm I. microscope 5. Cell membrane is like this............... D. oxygen J. diffusion E. R.Hooke K. cell wall 6. Cells are full of this............... F. nitrogen L. nucleus Years 7-8 Topic 6 Living Cells 8 copyright © 2008 keep it simple science www.keepitsimplescience.com.au  ® keep it simple science Copying is permitted according to the Site Licence Conditions only Worksheet 3 Identifying Cell Parts Student Name............................................. Label all the diagrams 4. a) Is this a plant or 1. animal cell?......................... a) Is this a plant or animal cell?......................... (b)......................... (c)...................... (d)......................... (b)......................... (c)...................... (green) (d)......................... (e)......................... (e)............................. (f)..................................... (f)........................... (green colour) 2. a) Is this a plant or animal cell?......................... 5. (b)......................... a) Is this a plant or animal cell?......................... (b)......................... (c)...................... (c)...................... (d)......................... (d)......................... 3. 6. a) Is this a plant or a) Is this a plant or animal cell?......................... animal cell?......................... (b)......................... (c)...................... (b)......................... (c)...................... This “tail” structure is called a (d)......................... flagellum. It allows this sperm cell to swim to find and fertilise the egg. (e)............................. (d)......................... Years 7-8 Topic 6 Living Cells 9 copyright © 2008 keep it simple science www.keepitsimplescience.com.au  ® keep it simple science Copying is permitted according to the Site Licence Conditions only Unicellular & Multicellular Organisms “Uni-” = one. “Multi-” = many. “cellular” = made of cells. Unicellular Organisms Multicellular Organisms There are many types of living things which All the familiar plants and animals are are composed of just one, single cell. multicellular... they are made up of billions of cells. Obviously, they are very small, and in some cases there may be millions of them living in The cells are a single drop of pond water. all pretty much the One of the most common types is the same size. bacteria. For example, the Bacteria live cells in a in every mouse are place you exactly the same size as the cells in an can imagine. elephant... the elephant simply has a lot They live in more cells. water & soil, and on and The single cell of a unicellular life-form must inside other Bacteria be able to do everything. magnified 20,000 X living things. In a multi-cellular creature, however, each You have millions of bacteria on your skin, in part of the body is specialised to do a your mouth and throughout your gut. particular job, and usually has many different specialist cells. For example, muscle cells are Bacterial cells are very small, often only about different to nerve cells, and blood cells are 1/ 1,000 mm long. different again. Through the Microscope You will probably learn how to use a microscope and look at some cells through it. You probably will NOT view bacteria (too small), but might see the following examples. Try to identify all the visible cell parts that you see. Paramecium Onion skin (unicellular organism) magnified 100X cytoplasm magnified 100X nucleus nucleus cell Human Blood Human Cheek Cells cytoplasm membrane magnified 400X magnified 400X cell wall cell membrane Even at maximum nucleus magnification you will Learn to sketch inside a probably not see any detail cytoplasm circle which represents the “field of view” of the microscope. Always label Sketch only a few of the your sketches cells, to scale. Years 7-8 Topic 6 Living Cells 10 copyright © 2008 keep it simple science www.keepitsimplescience.com.au  ® keep it simple science Copying is permitted according to the Site Licence Conditions only Micro-organisms These are organisms that are only visible through a microscope. Most are unicellular. Many are beneficial to the environment or to other life-forms. However, some are dangerous and can cause diseases. The Types of Micro-organisms Fungi There are a number of different kinds of The fungi are a type of living thing that living things which are microscopically includes mushrooms and “toadstools”, small. which, of course, are not microscopic. Bacteria have already been mentioned. However, some fungi are unicellular micro- Bacteria are all unicellular, and have organisms. These are known as “yeasts”. very small cells in a variety of shapes. Fungi were once thought to be a type of plant. However, we now recognise that their cells are neither plant-like, nor animal-like. In a later topic you will learn more. Viruses Some are Some are Spirals Viruses are the smallest of all, and are non- round. rod-shaped. cellular... they are not made of cells at all. Bacterial cells are quite different to Does this mean they are not really living either plants or animals. things? cell membrane Actually, they ARE considered living things, Protozoa even though they do not have cells. This is Protozoa are cytoplasm because they are always made by living unicellular and nucleus cells, and are composed of chemicals which have animal-like are typical of living things. cells. The modern scientific definition of a living Microscopic Algae thing is usually stated this way: These have cells which are plant-like. “All living things are composed of cells, They have chloroplasts and a cell wall or are the product of cells” on the outside. By this definition, viruses ARE living things. Some are unicellular, while others grow in long, thin threads of cells joined So, if viruses are not cellular, what are end-to-end. they? Spirogyra. Each virus is a tiny An alga which grows in filaments capsule of protein, with some genetic material inside. Spiral strings of Chains of plant-llike cells chloroplasts give (DNA or RNA) joined end-tto-e end Spirogyra its name Years 7-8 Topic 6 Living Cells 11 copyright © 2008 keep it simple science www.keepitsimplescience.com.au  ® keep it simple science Copying is permitted according to the Site Licence Conditions only Microbes Good and Bad Beneficial Micro-organisms Dangerous Micro-organisms Human Food Production The vast majority of micro-organisms are The unicellular fungus called yeast is vital for “good-guys”. Many are very helpful, as the production of bread, beer & wine. described on the left. Many others are simply harmless, and go about their lives without The living yeast makes the dough rise so that, doing any damage. when baked, the bread has its open, soft texture, and delicious taste. Some, however, are our enemies. Yeast causes fermentation to make the Microbes Cause Diseases alcohol in beer and wine. It is vital to the All infectious diseases (those you can catch) production of ethanol for adding to petrol. are caused by “germs”. Germs are really micro-organisms which infect our bodies Microbes Help Digestion and make us sick. Most plant-eating animals have Virus diseases include measles, ‘flu and bacteria living in their A.I.D.S. In fact, every virus causes disease in gut which help them some living thing. Even bacteria suffer from to digest tough, plant virus diseases. fibres. The best protection against viral disease is A mother koala will immunisation, which is when our bodies are feed her joey with “primed” to recognise and destroy an some of her stomach invading virus. contents so it gets the helpful bacteria it Bacterial Diseases will need to digest tough gum leaves. Many of the great killer-diseases of history are caused by bacteria. The “black death” Clean-Up & Recycle killed about 1/3 of the entire population of Probably the greatest benefit of micro- Europe in the Middle Ages. organisms is how they decompose all the dead leaves, animal wastes and dead Today, most bacterial diseases are controlled materials in the environment. by immunisation and/or by using antibiotic drugs. There are zillions of bacteria and fungi Protozoa & Fungi which live in the soil A few diseases are caused by protozoa. The or in the mud under most important is malaria, which kills millions lakes and oceans. of people each year in Africa and Asia. They feed on all the Despite 100 years of effort, we still cannot wastes and dead control malaria in some tropical areas. remains and cause it to rot away. A few diseases are caused by fungi. These This not only cleans up the environment, but are mostly skin infections (e.g. tinea) and are it recycles vital chemicals back into the soil rarely life-threatening. Fungal disease can so plants can continue growing. usually be cured by anti-fungal drugs. Years 7-8 Topic 6 Living Cells 12 copyright © 2008 keep it simple science www.keepitsimplescience.com.au  ® keep it simple science Copying is permitted according to the Site Licence Conditions only Worksheet 4 Microbes Student Name............................................. Fill in the blanks protein with some k)............................ inside. “Unicellular” means a living thing which is made up of a)...................................... Many microbes are beneficial, such as All unicellular organisms are l)........................... which is used to make “microbes”, which means they can only bread, and to brew m)......................... be seen with a b)................................. and............................... All the familiar plants and animals are Other microbes live in the gut of animals c)................................. organisms. They and help them to n)........................... are made up of d)............................ of.................................. cells. They contain many different types of cells, each e)................................... to Many o)........................ and....................... do a particular task in their body. live in the soil and cause p)................................... to rot away. This There are many different types of micro- not only cleans up the environment, but organisms: q)................................. many important chemicals back into the soil. f)............................, which have very small cells in various shapes. Some microbes causes r)......................... Every s)....................... causes a disease Protozoa, which have g).....................- in some living thing. The best protection like cells. against viral disease is t).......................... Microscopic h)............................, which Many other diseases are caused by have plant-like cells. u).............................. including many of the great killer-diseases of history. i)......................, which are single-celled fungi. Not many protozoa cause disease, but one notable example is v)......................... j)........................... These are non- which kills millions of people each year. cellular, and consist of a tiny capsule of Worksheet 5 Student Name............................................. Which Type of Microbe... a) has animal-like cells?.......................... d) is the cause of malaria?...................... b) is non-cellular?......................... e) has plant-like cells?......................... c) is important for cleaning up the f) often lives in the gut environment by decomposing dead and of plant-eaters and helps waste matter? (2 answers) them digest food?........................................................ and............................ g) caused most of the epidemic diseases in history?......................... Years 7-8 Topic 6 Living Cells 13 copyright © 2008 keep it simple science www.keepitsimplescience.com.au  ® keep it simple science Copying is permitted according to the Site Licence Conditions only How Knowledge of Microbes Has Changed Society For most of human history, people People and governments came to realize the believed that diseases were due to evil importance of clean water, personal hygiene curses or spirits, or were punishments and sanitary sewerage and garbage disposal. from God, or other supernatural events. Mass immunisation and antibiotic drugs Many children died young. Epidemics of have reduced the impacts of infectious disease killed millions. Many minor diseases dramatically. Smallpox, a virus injuries led to fatal infections. The disease which once killed millions, has been average life expectancy was only about eliminated world-wide. 40 years. (Today it is about 80 years.) In developed countries like Australia, It was the great French cases of serious infectious diseases scientist Louis Pasteur are now quite rare, and a death from an (1822-95) who led the infection is considered a failure of the way to a greater health system. understanding. People know about “germs” and the He proved that some importance of keeping clean. Parents diseases were caused get their children immunised to prevent by microscopic them getting diseases. “germs”. Soon, many Portrait of Louis Pasteur more were identified. All these wonderful changes can be in his laboratory attributed to scientific knowledge. He also led the way to developing the Without the advances in the Health process of immunisation as a way to Sciences over the last 150 years protect against infectious disease. you might already be dead! People Make Choices Attitudes to Immunisation What Happens Next? Unfortunately, there is an “urban myth” that Although it is tragic when a child is harmed sometimes being immunised actually causes by a reaction to a vaccine, what happens disease. For example, it is widely believed when people make a decision not to that “Fluvax” (the vaccine used to immunise immunise is even more tragic. against infuenza) can give you a ‘flu infection. If everyone in a community is immunised then the disease basically ceases to exist In fact, the scientific evidence is that this is because there is no “reservoir” of infected totally false. people to pass the disease on. In other cases, there actually is a slight risk to However, when enough people choose not to being immunised. In a very, very small have their children immunised, then the number of cases, the vaccine for a disease disease continues to infect people. can cause a reaction in a child which is fatal, or causes permanent brain damage. The health risk of not being immunised is actually much higher than the risk of a This scares many people, who then decide reaction to the vaccine, but some people not to have their children immunised. continue to make that choice. Years 7-8 Topic 6 Living Cells 14 copyright © 2008 keep it simple science www.keepitsimplescience.com.au  ® keep it simple science Copying is permitted according to the Site Licence Conditions only How Unicellular Organisms Reproduce Genetic Information Cell Division Every type of living thing must reproduce. Unicellular organisms reproduce by simply Mice have baby mice, gum trees make seeds dividing in two. This is called “Mitosis”. which grow into new gum trees, and bacteria make more bacteria. Each cell first makes a duplicate copy of its DNA. Then the 2 sets of genetic information Each living thing carries information on how are separated. At this point it is as if the cell to make offspring of its own type. Mice never has 2 nuclei (plural of nucleus). make gum tree seeds, and horses do not give birth to cats. Then the cell itself divides into 2 smaller cells. Each new cell is only half-size but has a The information needed to accurately complete nucleus with a full copy of the reproduce the same type of living thing is genetic information in its DNA. located in the nucleus of every living cell. Finally, each cell can then grow to full size Information is stored in before the whole process starts again. a chemical known as DNA. DNA molecules Mitosis cell division is the way that unicellular are the largest known organisms reproduce. Under ideal and carry a “code” conditions, some bacteria can go through the within their helix-shape whole cycle in about 30 minutes. structure. If you started with 1 bacterial cell, and it divided in two every hour, how many would there be after 1 day? It is the DNA inside Time (hours) > 0 1 2 3 4 5 every cell nucleus No. of Bacteria 1 2 4 8 16 32 which controls the cell If you continue this calculation to 24 hours, and all its functions. you will have over 16 million cells! In multicellular organisms, mitosis is how The key to new cells are made for growth. You started reproduction is to out as 1 single cell, but now have billions. make copies of the DNA Each cell has the complete genetic and pass it on to the next generation. information (DNA) that makes you, you. Mitosis Cell Division Each Nucleus new cell grows to full DNA size. Original DNA DNA copies are Cell 2 half-s size cells cell. duplicated. separated. divides. with identical 2 nuclei form. genetic information. Years 7-8 Topic 6 Living Cells 15 copyright © 2008 keep it simple science www.keepitsimplescience.com.au  ® keep it simple science Copying is permitted according to the Site Licence Conditions only Worksheet 6 Cell Division Student Name............................................. Fill in the blank spaces Genetic information is stored in the Next, the cell splits into two cells. Each a)............................... (organelle) in every one is only h).................-size, but each living cell in the form of the chemical has a complete copy of the called b)....................... For reproduction i)..................... to occur, the information must be c)........................ and passed onto the Each new cell now j).......................... to next generation. full size, and then the process can start again. Unicellular organisms reproduce by simply d)........................................... This In multicellular organisms, cell division cell division is called e)............................. is used for k)............................. Each living thing begins with l)................. cell. The first step is to f)............................ the This becomes billions by repeated DNA. Then the 2 copies are separated so m).......................................... Each cell the cell really has 2 g)...................... has a complete copy of the n).................. Worksheet 7 Mitosis The process of cell division by Mitosis is all jumbled up in these diagrams and captions. Cut them out and re-arrange into correct order. Connect with arrows. Nucleus DNA Original cell. Cell DNA divides. Each duplicated. new cell 2 half-s size cells grows with identical DNA copies are to full genetic separated. size. information. 2 nuclei form. Years 7-8 Topic 6 Living Cells 16 copyright © 2008 keep it simple science www.keepitsimplescience.com.au  ® keep it simple science Copying is permitted according to the Site Licence Conditions only Topic Test - Living Cells Answer all questions Student Name............................................. in the spaces provided. Score /25 1. (10 marks) 3. (5 marks) True or False? T or F Label the parts of this cell. a) Most cells can be seen (a)......................... (b)...................... (green) with the naked eye............... (c)......................... b) All cells have a cell wall............... c) All cells have a cell membrane........... d) The nucleus controls all the functions of a cell............... (d)......................... e) The cells in a large animal are the same size as the cells in a small animal.............. f) Protozoa are unicellular, with plant-like cells............... (e)........................... g) A virus has no cells............... h) The first man to see cells was Louis Pasteur............... f) Is this cell plant or animal?................... i) Yeast is a disease- causing virus............... 4. (2 marks) j) DNA is copied before The cell membrane is described as cell division.............. “semi-permeable”. Briefly, what does this mean? 2. (4 marks) For each pair of items, state clearly what is the difference between them? 5. (3 marks) a) unicellular and multicellular The cells that are formed by mitosis are referred to as “daughter cells”. The original cell before mitosis can be called the “parent cell”. a) How does the size of a daughter cell (immediately after mitosis) compare to the parent cell? b) cell membrane and cell wall b) How does the DNA content of a daughter cell compare to the parent cell? c) What is the vital first step before a cell begins to divide? Years 7-8 Topic 6 Living Cells 17 copyright © 2008 keep it simple science www.keepitsimplescience.com.au  ® keep it simple science Copying is permitted according to the Site Licence Conditions only Answer Section Worksheet 4 a)one single cell b) microscope c) multicellular d) many / billions Worksheet 1 e) specialised f) bacteria a) cells b) microscope g) animal-like h) algae c) one d) many / billions i) yeasts j) viruses e) 1/10 (0.1) f) Robert Hooke k) genetic information / DNA g) nucleus h) cytoplasm l) yeast m) beer & wine i) organelles j) cell membrane n) digest their food k) what moves in or out o) bacteria & fungi l) cell wall m) chloroplasts p) wastes / dead matter n) light o) photosynthesis q) recycles r) diseases p) oxygen q) carbon dioxide s) virus t) immunisation r) cell membrane s) semi-permeable u) bacteria v) malaria t) diffusion Worksheet 5 Worksheet 2 a) protozoa b) viruses 1. I 6. C c) bacteria & fungi 2. E 7. J d) protozoa e) microscopic algae 3. G 8. D f) bacteria g) bacteria 4. L 9. A 5. H 10. K Worksheet 6 a) nucleus b) DNA c) copied / duplicated Worksheet 3 d) dividing in 2 e) mitosis 1. f) copy g) nuclei a) plant b) nucleus h) half-size i) DNA c) cytoplasm d) cell membrane j) grows k) growth e) cell wall f) chloroplast l) one m) cell divisions 2. n) DNA a) animal b) cell membrane c) cytoplasm d) nucleus Worksheet 7 3. see diagram page 15 a)plant b) cell wall Original DNA c) nucleus d) cytoplasm cell. duplicated. e) cell membrane 4. DNA copies are a) plant b) chloroplast separated. c) cell wall d) cell membrane 2 nuclei form. Cell e) cytoplasm f) nucleus divides. 5. a) animal b) nucleus 2 half-s size cells with identical Each c) cell membrane d) cytoplasm genetic new 6. information. cell a) animal b) cell membrane grows c) cytoplasm d) nucleus to full size. Years 7-8 Topic 6 Living Cells 18 copyright © 2008 keep it simple science www.keepitsimplescience.com.au  ® keep it simple science Copying is permitted according to the Site Licence Conditions only Topic Test Answers 3. 1. a) chloroplast a) F b) F c) T d) T e) T b) cell wall f) F g) T h) F i) F j) T c) cell membrane d) cytoplasm 2. e) nucleus a) unicellular = made up of only 1 cell. f) plant multicellular = made of many cells 4. Semi-permeable means that some b) Cell membrane surrounds all cells, substances can move through it easily, and controls what goes in and out. while others cannot get through. Cell wall is a tough layer which surrounds plant cells (not animal cells). 5. a) half-size b) identical c) copy the DNA Years 7-8 Topic 6 Living Cells 19 copyright © 2008 keep it simple science www.keepitsimplescience.com.au