OCR Biology Chapter 6 Review PDF

## REVIEW 6 ### Multiple choice questions 1. Identify which of the following is not found in an animal cell. - A mitochondria - B a cell wall - C cytosol - D a nucleus 2. Identify which important process takes place in the mitochondria of a cell. - A photosynthesis - B exc...

## REVIEW 6 ### Multiple choice questions 1. Identify which of the following is not found in an animal cell. - A mitochondria - B a cell wall - C cytosol - D a nucleus 2. Identify which important process takes place in the mitochondria of a cell. - A photosynthesis - B excretion - C cellular respiration - D cell division 3. Identify the term that describes the organism that catches the disease. - A a cell - B a pathogen - C a host - D an organism ### Short answer questions #### Remember and understand 4. Identify the first person to describe a cell. 5. Describe the benefit of using a stain when viewing some specimens. 6. Describe the cell theory. 7. Identify two types of microscopes. 8. Explain why a specimen needs to be very thin to be viewed under a light microscope. 9. Compare a mitochondrion and a chloroplast. 10. Contrast fungal cells and bacterial cells. 11. Define the following words: - a nucleus - b mitochondrion - c chloroplast - d binary fission - e pathogen. 12. Ribosomes are found in every cell on Earth. Describe the function that ribosomes perform in cells. 13. Distinguish between the terms 'unicellular' and 'multicellular'. Provide two examples of each. ### Apply and Analyse 14. Explain why antibiotics cannot be used to treat Covid-19. 15. A cell membrane is 'partially permeable'. This means that only certain substances can cross the membrane. Identify some substances that would get into the cell and some that would need to get out. 16. Explain why unicellular organisms are always tiny, and why multicellular organisms are made up of many cells instead of one large cell. 17. Explain why a doctor will not prescribe antibiotics if you are sick with a cold or flu. 18. Animal cells have mitochondria, while plant cells have both mitochondria and chloroplasts. Explain this difference. 19. Light microscopes allow you to view living cells. Describe why the cells need to be thin to be seen down a light microscope. 20. Calculate the magnification of a cell that is viewed with a 'x40' objective lens and a 'x10' eyepiece lens. ### Evaluate 21. Two students prepare slides from different sections of a spring onion under a light microscope in their school laboratory. James views a section of the green leafy part and observes many chloroplasts within each cell, but has difficulty identifying a nucleus in each cell. Emily views a section of the white stem of the plant. She comments that a nucleus is clearly visible in most of the cells, but does not identify any chloroplasts. - a Determine why James identified many chloroplasts within each cell when they appeared to be absent from the cells viewed by Emily. - b Emily commented that she could identify a nucleus in most cells. Evaluate whether it is possible for a plant cell not to have a nucleus (by describing the function of a nucleus, describing the importance of a nucleus to the cell staying alive and deciding if it is possible for a plant cell to live without a nucleus). 22. Write a very short creative story about a virus. Your story needs to be from the point of view of a cell. The first line of your story is: 'Once upon a time, a virus arrived for an uninvited visit'. 23. Identify the microscope most likely to have created the images in Figure 1. Justify your decision (by describing the features in the picture that are unique and deciding which microscope would allow these features to be seen). ### Discuss how our understanding of cell structure and function has changed with the development of the microscope. ### Social and ethical thinking 26. Explain why a doctor should not prescribe antibiotics for a viral infection by describing: - a the effectiveness of antibiotics for making the person healthy - b the long-term effects of overprescribing antibiotics on antibiotic resistance. 27. Stem cells are cells in multicellular organisms that haven't become specialised yet - they're like blank canvases. Scientists us stem cells to help with the understanding of how diseases happen, and to create healthy cells to replace damaged or diseased cells in the human body. Scientists and researchers also use stem cells to test new drugs, instead of having to use humans or animals. Explain why it might be more ethical to use stem cells to test new drugs, instead of using human or animal testing. 28. A patent is a right or title that is given to the inventor of something useful, to stop other people from making or selling the thing that has been invented. Ernst Chain wanted to get a patent on penicillin when it was first produced; however, Howard Florey thought it would be unethical to do so because it is a life-saving drug. Evaluate both sides of the argument to patenting penicillin, from the perspective of both Ernst Chain and Howard Florey. ### Critical and creative thinking 29. Similes are often used in creative writing to compare two things using the words 'like' or 'as'. Explain the similarities that allow these similes to be used. - a Cells are like building blocks. - b The nucleus is like a control centre. - c The mitochondrion is like a power station. 30. Describe how our understanding of how living things function changed with the development of the microscope. ### Research 31. Choose one of the following topics for a research project. A few guiding questions have been provided for you, but you should add more questions that you want to investigate. Present your research in a format of your own choosing, giving careful consideration to the information you are presenting. - Use the lenses from an old pair of reading glasses or a magnifying glass to create a model of a microscope. Describe how your model is similar to and different from Hooke's microscope and modern compound microscopes. - Figure 1 Microscope images.