1. Beginnings and Endings Answers BeginningsEndings Cell division is essential (needed) for growth and repair During cell division the parent cell divides to form two identical daughter cells The daughter cells always have the same number of chromosomes Uncontrolled cell division can lead to cancer Cell Division

2. DNA, Genes & Chromosomes BeginningsEndings The chromosomes are found in the nucleus of a cell Genes are found on chromosomes Lots of genes make up strands of DNA DNA is like a code for making protein Genes are passed on from parents to offspring DNA can be used to help solve crime because each person’s DNA is different to everyone else

3. Therapeutic Uses of Cells BeginningsEndings Genetic Engineering can be used to make insulin Genetic Engineering involves the transfer of a gene from one organism to a different organism Stem cells are unspecialised cells An example of an organism that is often used in Genetic Engineering is bacteria Stem cell technology uses stem cells to grow new organs for transplant

4. Enzymes BeginningsEndings Enzymes are found in all living cells Enzymes are used by cells to speed up chemical reactions Each enzyme is specific which means it will only act on one type of substance Enzymes are unchanged during chemical reactions so they can be used again Washing powders that contain enzymes are called biological detergents Each enzyme works best in certain conditions of temperature and pH called the optimum

5. Microorganisms in Industry BeginningsEndings Microorganisms can be useful in industry because They multiply very quickly Examples of useful microorganisms include yeast and bacteria Yeast is used in industry to make Bread and beer Bacteria are used in industry to make Cheese and yoghurt and to break down sewage Bacteria and yeast can be grown in large containers called fermenters

6. Photosynthesis BeginningEnding Photosynthesis is a chemical reactions that happens when plants use light energy to make food For photosynthesis to happen plants need light, water, carbon dioxide, chlorophyll and a suitable temperature Chlorophyll is a green chemical found in leaves that can trap energy from light Plants make sugars called glucose that are stored as starch or used for growth The waste product of photosynthesis is oxygen If light or carbon dioxide are in short supply or if it too cold then the rate of photosynthesis will be limited or slower than normal

7. Factors affecting Respiration BeginningEndings Respiration is a process cells use to Release energy from food There are two kinds of respiration: Aerobic and anaerobic Aerobic respiration means With oxygen Anaerobic respiration means Without oxygen Aerobic respiration produces carbon dioxide and water As waste products Anaerobic respiration in animals produces Lactic acid Anaerobic Respiration in plants and yeast produces Alcohol and carbon dioxide Respiration needs enzymes to happen so the speed it happens is affected by Temperature

8. Revision Cloze Passage Answers Key Area 1. Cell Division and its role in growth and repair.

9. 1.Genes are located on chromosomes in the nucleus. 2.Genes are made of DNA which carries the instructions to make proteins. 3.Each individuals DNA is unique. 4.Genes are passed from parents to offspring. Word Bank nucleusDNAproteinparents offspringgenesunique Key Area 2. DNA, genes and chromosomes.

10. Key Area 3. Therapeutic use of cells. 1.Genetic engineering can be used to produce bacteria that can produce human insulin. This can be used to treat people who are diabetic. 2.Genetic engineering can be used to produce human growth hormone. This can be used to treat dwarfism. 3. Stem cells exist that can be used to grow artificial tissue or organs. Wordbank diabetictissuedwarfisminsulin geneticgrowth hormoneengineeringstem bacteria

11. Key Area 4. Properties of enzymes and use in industries. 1. Enzymes are found in all living cells. 2.Enzymes are specific - they only act on one substrate. For example, amylase only acts on starch and catalase acts only on hydrogen peroxide. 3.Enzymes speed up reactions and remain unchanged by the reaction. 4.Enzymes can build up and break down molecules. 5.Enzymes can be used in a range of industries. For example, rennet is used to make cheese. Wordbank specificcatalasespeed upunchanged starchEnzymesbuild uprennet break downlivingcheese

12. Key Area 5. Properties of microorganisms and use in industries. Microorganisms grow rapidly and can be used as a source of foods like Quorn and Marmite. Microorganisms include bacteria and fungi and are to make a wide range of useful products. Yeast is a fungus and is used in the baking and brewing industry. Yeast is also used to make the fuel Gasohol. Bacteria are used to produce yoghurt, cheese and biofuels. The fungus Penicillium is used to make the antibiotic penicillin. Wordbank microorganismsyeastQuornpenicillin usefulrapidlyGasoholMarmite cheesebaking

13. Key Area 6. Photosynthesis- Limiting factors. 1. Plants use the process photosynthesis to convert light into food. 2. The rate of photosynthesis can be controlled by three factors. Carbon dioxide concentration, light intensity and temperature. They are described as limiting factors 3.If any of the limiting factors are in short supply, photosynthetic rate will be slow. 4.If limiting factors are present at optimum levels, increased photosynthesis will lead to faster plant growth. Wordbank factorslimitingintensitythree plantsphotosynthesisslowgrowth shortconcentrationsunlight

14. Key Area 7. Factors affecting respiration 1.Respiration is the process that releases energy in cells. There are two types of respiration. 2.When oxygen is present, all cells carry out aerobic respiration and convert glucose into water and carbon dioxide. A large amount of energy is released. 3.When oxygen is absent, cells carry our anaerobic respiration. A small amount of energy is realised. In plant and yeast cells, glucose is converted into alcohol and carbon dioxide. In animal cells, glucose is converted into lactic acid. 4.Respiration is controlled by enzymes and is affected by temperature. Wordbank enzymeslargealcoholtemperature aerobicsmallpresentglucose oxygenenergyRespiration (x2)two

15. Key Area 8. Controversial biological procedures. 1.Immunisation. Humans can use immunisation to protect people from common diseases such as small pox, measles and mumps. Some people believe that immunisations are unsafe and can lead to other problems such as autism in children. 2.Natural selection. The theory of natural selection explains how all organisms evolved on Earth. It does not use religion to describe how this happened. Some religious people believe that life was created by God. Some people believe the Book of Genesis in the bible describes how all plant and animals was created. 3.Stem cell technology. Human embryos can be manipulated to become stem cells. Stem cells can be used to grow replacement skin and heart tissue. This is controversial as a human embryo cell has to be destroyed to carry out this procedure. 4.Mammalian cloning. A clone is an identical copy of a single organism. Scientists have been able to produce clones of many mammalian species. These clones can be used to improve yield in agriculture. For example, a pig that produces a large litter of piglets could be cloned and the number of piglets produced by farmers would increase greatly. Some people feel that this technology could be used to clone humans and is cruel to animals. Wordbank EarthautismGodreligion small poxBiblenatural selectionhumans pigletsincreasehumansanimals stemembryosheartmammalian mumpscloneyield