...www.asbiology101.wordpress.com An introduction to the microscope and magnification MAGNIFICATION AND RESOLUTION Because cells are too small to be seen with the naked eye, the light microscope was developed to produce enlarged and more detailed images of cells. The magnification of an image is how much bigger it appears under the microscope than it is in real life, and is worked out using the following formula: magnification = image size ÷ actual size unit metre decimetre centimetre millimetre micrometre nanometre picometre symbol m dm cm mm μm nm pm metres 1 0.1 0.01 0.001 0.000 001 0.000 000 001 0.000 000 000 01 However, magnification on its own does not increase the level of detail seen, it just increases the size. The term resolution refers to the ability to see two distinct points separately. For example, if the resolution of a light microscope is 200nm (0.2μm), this means it can see any two different points as separate objects if they are 200nm apart or more; but if they are any closer than this amount, they appear as one object. THE LIGHT MICROSCOPE Light microscopes use a number of lenses to produce an image that can be viewed directly at the eyepiece. Light passes from a bulb under the stage, through a condenser lens and then through the specimen. This beam of light is passed through an objective lens and then the eyepiece lens. The light microscope usually has a number of objective lenses which can be rotated into position...
Words: 8313 - Pages: 34
...Venomous coral snakes and harmless scarlet kingsnakes both have bands of red, yellow, and black. Birds, bats, and butterflies all have wings. When a dog feels hot, it hangs it tongue out and pants. Question 2 1 / 1 pts Without this part of an experiment, a scientist would have no way of knowing if the treatment worked or not: Control group The control group is not subjected to the experimental treatment, thus, if there is a significant change in the test group but not the control group, then the treatment worked. Hypothesis Conclusion Observation Testing Question 3 1 / 1 pts Which of the following is not considered a basic theory of biology? Gene Ecosystem Cell Homeostasis The notch is an adaptation for feeding on shrubs. an experimental variable. a species. Question 7 1 / 1 pts Which of the following levels of taxonomy is the least inclusive? Class Order Family Genus The levels of taxonomy are, from most to least inclusive: domain, kingdom, phylum, class, order, family, genus, and species. Phylum Question 8 1 / 1 pts A possible explanation for a natural event is known as Atomic Atomic theory is a basic theory of chemistry and physics, not biology. Question 4 1 / 1 pts While examining a drop of pond water under the...
Words: 13000 - Pages: 52
...Biology Units 3 &4 Notes -Chapter 1- The Chemical Nature of Cells | |Protein |Carbohydrates |Fats |Nucleic acid | |Monomer |Amino acids |Monosaccharaide |Fatty acids, glycerol |Nucleotide | |Example |2o Amino acids |Glucose, Fructose, Ribose |Triglycerides |Adenine, Cytosine, Guanine | | | | |Steroids, Phospholipids |&Thymine/ Uracil | |Diagram | | | | | | | | | | | | | | | | | | | | | | | |Bonding (how units combine – |1st structure-strong covalent |Strong covalent glycoside |Rarely ever forms polymer |covalent bonds b/w sugar | |polymers ...
Words: 8693 - Pages: 35
...when the plant cells and the human cells were viewed in the microscope, they took on differentiating forms, enabling visual differentiation of the two forms of cells. The onion skin cell, an example of a plant cell, generally has a rigid, rectangular shape. The onion skin cells were positioned beside each other (length touching length, width touching width) and formed a checkered pattern. When observing the onion skin cell, we noticed that the cells took on a brick-like structure and within the cells, small dots (the nuclei) can be seen.When we first looked into the microscope, the microscope’s total magnification was 10X so there were about a hundred rows of rectangular cells (see diagram provided), but as we changed magnifications, the number of cells in the field of view decreased.When we viewed the onion skin cells at 40X total magnification, we noticed the nuclei of the cells looked clearer and larger and we were able to study the cell with more understanding than when we used the first magnification. The organelles that we were able to see in this type of cell were the nucleus, the cytoplasm and the cell wall. | -----The cheek cell, an example of an animal cell, generally has a circular, oval shape. the animal cell structure is the most prominent in human cheek cells. animal cell simply stands on it's own without being closely packed together. We noticed that the cells were secluded and spread out (see diagram provided), when we viewed the cheek cells at 40X total magnification...
Words: 2735 - Pages: 11
...Cells, Exchange and Transport Cells (a) state the resolution and magnification that can be achieved by a light microscope, a transmission electron microscope and a scanning electron microscope; Resolution Magnification Light microscope 200nm x1,500 Transmission Electron Microscope 0.1nm x500,000 Scanning Electron Microscope 0.1nm X100,000 (b) explain the difference between magnification and resolution; Magnification is the degree to which the size of an image is larger than the image itself. Resolution is the degree to which it is possible to distinguish between two objects that are very close together. (c) explain the need for staining samples for use in light microscopy and electron microscopy; A lot of biological material inside a cell isn’t coloured, so it might be difficult to distinguish between different features. Coloured stains are used to stain specimens for use with the light microscope. Chemicals which bind to other chemicals on, or in, the specimen, which allows the specimen be to seen. Some chemicals bind to specific structures, such as Acetic orcein staining DNA red. Electron micrographs start off black and white, with the colour being added by a specialised computer program afterwards. (d) calculate the linear magnification of an image; Image size =Actual size x Magnification (e) describe and interpret drawings and photographs of eukaryotic cells as seen under an electron microscope and be able to recognise the following structures: ...
Words: 7700 - Pages: 31
...6 Cellular Respiration: Obtaining Energy from Food Muscles in action. Sprinters, like all athletes, depend on cellular respiration to power their muscles. CHAPTER CONTENTS Energy Flow and Chemical Cycling in the Biosphere 92 Cellular Respiration: Aerobic Harvest of Food Energy 94 Fermentation: Anaerobic Harvest of Food Energy 101 CHAPTER THREAD Aerobic versus Anaerobic Lifestyles BIOLOGY AND SOCIETY Marathoners versus Sprinters THE PROCESS OF SCIENCE What Causes Muscle Burn? EVOLUTION CONNECTION Life before and after Oxygen 91 102 103 Aerobic versus Anaerobic Lifestyles BIOLOGY AND SOCIETY Marathoners versus Sprinters Track-and-field athletes usually have a favorite event in which they excel. Some runners specialize in sprints of 100 or 200 meters. Others excel at longer races of 1,500, 5,000, or even 10,000 m. It is unusual to find a runner who competes equally well in both 100-m and 10,000-m races; most runners are more comfortable running races of particular lengths. It turns out that there is a biological basis for such preferences. The muscles that move our legs contain two main types of muscle fibers: slow-twitch and fast-twitch. Slow-twitch muscle fibers can contract many times over a longer period but don’t generate a lot of quick power for the body. They perform better in endurance exercises requiring slow, steady muscle activity, such as marathons. Fast-twitch muscle fibers can contract more quickly and powerfully than slow-twitch fibers but also...
Words: 24897 - Pages: 100
...How is the scientific method used to solve problems? Scientific method used to solve problems by keen observations, rational analysis, and experimentation. Observation: Closely observe the physical world around you. How is the scientific method used to solve problems? Scientific method used to solve problems by keen observations, rational analysis, and experimentation. Observation: Closely observe the physical world around you. Question: Recognize a question or a problem. Hypothesis: An educated guess or a reasonable explanation. When the hypothesis can be tested by experiment, it qualifies as a scientific hypothesis Prediction: Consequences that can be observed if the hypothesis is correct. The consequences should be absent if the hypothesis is not correct. Conclusion: Formulate the simplest general rule that organizes the hypothesis, predicted effects, and experimental findings. What is the principle of falsifiability? For a hypothesis to be considered scientific it must be testable?it must, in principle, be capable of being proven wrong. Fact: A phenomenon about which competent observers can agree. Theory: A synthesis of a large body of information that encompasses well-tested hypotheses about certain aspects of the natural world. Law: A general hypothesis or statement about the relationship of natural quantities that has been tested over and over again and has not been contradicted. Also known as a principle. Evidence: which...
Words: 33649 - Pages: 135
...well-adapted for nocturnal hunting. E) Leopards are normally solitary animals. Answer: A Topic: Opening Essay Skill: Factual Recall 2) Life is organized in a hierarchical fashion. Which of the following sequences correctly lists that hierarchy as it increases in complexity? A) ecosystem, population, organ system, cell, community, molecule, organ, organism, tissue B) cell, molecule, organ system, organ, population, tissue, organism, ecosystem, community C) organism, organ system, tissue, population, organ, community, cell, ecosystem, molecule D) molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem E) ecosystem, molecule, cell, tissue, organism, organ system, organ, community Answer: D Topic: 1.1 Skill: Factual Recall 3) What is the difference between a tissue and an organ system? A) The tissue level of organization is more inclusive than the organ system level. B) Tissues are not composed of cells; organ systems are composed of cells. C) A tissue cannot exist unless it is a component of an organ system, whereas an organ system can exist independently of tissues. D) An organ system includes tissues. E) Tissues are not considered to be living; organ systems are considered to be living. Answer: D Topic: 1.1 Skill: Factual Recall 4) The...
Words: 9744 - Pages: 39
...are well-adapted for nocturnal hunting. E) Leopards are normally solitary animals. Answer: A Topic: Opening Essay Skill: Factual Recall 2) Life is organized in a hierarchical fashion. Which of the following sequences correctly lists that hierarchy as it increases in complexity? A) ecosystem, population, organ system, cell, community, molecule, organ, organism, tissue B) cell, molecule, organ system, organ, population, tissue, organism, ecosystem, community C) organism, organ system, tissue, population, organ, community, cell, ecosystem, molecule D) molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem E) ecosystem, molecule, cell, tissue, organism, organ system, organ, community Answer: D Topic: 1.1 Skill: Factual Recall 3) What is the difference between a tissue and an organ system? A) The tissue level of organization is more inclusive than the organ system level. B) Tissues are not composed of cells; organ systems are composed of cells. C) A tissue cannot exist unless it is a component of an organ system, whereas an organ system can exist independently of tissues. D) An organ system includes tissues. E) Tissues are not considered to be living; organ systems are considered to be living. Answer: D Topic: 1.1 Skill: Factual Recall 4) The tree...
Words: 9743 - Pages: 39
...A2 Biology Unit 5 page 1 AQA A2 Biology Unit 5 Contents Specification Human Nervous system Nerve Cells The Nerve Impulse Synapses Receptors Muscle Animal Responses Control of Heart Rate The Hormone System Homeostasis Temperature Homeostasis Blood Glucose Homeostasis Control of Mammalian Oestrus Plant Responses The Genetic Code Protein Synthesis Gene Mutations Stem Cells Control of Gene Expression Biotechnology DNA sequencing Southern Blot In vivo cloning Genetically Modified Organisms Gene Therapy Genetic Screening and Counselling 2 4 6 0 14 17 24 28 30 33 34 38 42 44 48 50 54 57 63 66 71 76 80 85 89 92 Molecular Genetics These notes may be used freely by A level biology students and teachers, and they may be copied and edited. Please do not use these materials for commercial purposes. I would be interested to hear of any comments and corrections. Neil C Millar (nmillar@ntlworld.co.uk) Head of Biology, Heckmondwike Grammar School High Street, Heckmondwike, WF16 0AH Jan 2010 HGS Biology A-level notes NCM 8/09 A2 Biology Unit 5 page 2 Biology Unit 5 Specification Control Systems Organisms increase their chance of survival by responding to changes in their environment. The Nerve Impulse The structure of a myelinated motor neurone. The establishment of a resting potential in terms of differential membrane permeability, electrochemical gradients and the movement of sodium and potassium ions. Changes in membrane permeability lead to depolarisation and the...
Words: 26586 - Pages: 107
...water (up plant); ACCEPT alternative wording for transport e.g. movement DO NOT ACCEPT up and down DO NOT ACCEPT water and sugars transports, minerals / ions, (up plant); ACCEPT alternative wording for transport IGNORE ref nutrients / solutes DO NOT ACCEPT sugars support (plant / stem / shoot); ACCEPT keeps plant upright 1 max (ii) Functions: F1 (lignin), strengthens / thickens, the (xylem) wall; ACCEPT support only if in specific context of supporting the xylem wall F2 waterproofing (wall) / AW; ACCEPT waterproofs cell F3 (improving) adhesion of water (molecules); DO NOT ACCEPT adhesion and cohesion when used together F4 (spiral) pattern allows flexibility / stretching / movement; Flexibility / stretching must ref, pattern of lignin laid down i.e. spirals Explanation: E1 prevents collapse of xylem; E2 (water) under tension / at low pressure / negative pressure; DO NOT CREDIT loss of water unqualified E3 reduces (lateral) loss of water, through wall; E4 increases capillarity / AW; E5 prevents stem breaking / AW; Award mark(s)...
Words: 15986 - Pages: 64
...Answers to Conceptual Integrated Science End-of-Chapter Questions Chapter 1: About Science Answers to Chapter 1 Review Questions 1 The era of modern science in the 16th century was launched when Galileo Galilei revived the Copernican view of the heliocentric universe, using experiments to study nature’s behavior. 2 In Conceptual Integrated Science, we believe that focusing on math too early is a poor substitute forconcepts. 3 We mean that it must be capable of being proved wrong. 4 Nonscientific hypotheses may be perfectly reasonable; they are nonscientific only because they are not falsifiable—there is no test for possible wrongness. 5 Galileo showed the falseness of Aristotle’s claim with a single experiment—dropping heavy and lightobjects from the Leaning Tower of Pisa. 6 A scientific fact is something that competent observers can observe and agree to be true; a hypothesis is an explanation or answer that is capable of being proved wrong; a law is a hypothesis that has been tested over and over and not contradicted; a theory is a synthesis of facts and well-tested hypotheses. 7 In everyday speech, a theory is the same as a hypothesis—a statement that hasn’t been tested. 8 Theories grow stronger and more precise as they evolve to include new information. 9 The term supernatural literally means “above nature.” Science works within nature, not above it. 10 They rely on subjective personal experience and do not lead to testable hypotheses. They lie outside...
Words: 81827 - Pages: 328
...Chapter 10 Chapter 11 Chapter 12 Chapter 13 Chapter 14 Chapter 15 Chapter 16 Chapter 17 Chapter 18 Chapter 19 Chapter 20 Chapter 21 Chapter 22 Chapter 23 Introduction to Biochemistry Water Amino Acids and the Primary Structures of Proteins Proteins: Three-Dimensional Structure and Function Properties of Enzymes Mechanisms of Enzymes Coenzymes and Vitamins Carbohydrates Lipids and Membranes Introduction to Metabolism Glycolysis Gluconeogenesis, The Pentose Phosphate Pathway, and Glycogen Metabolism The Citric Acid Cycle Electron Transport and Oxidative Phosphorylation Photosynthesis Lipid Metabolism Amino Acid Metabolism Nucleotide Metabolism Nucleic Acids DNA Replication, Repair, and Recombination Transcription and RNA Processing Protein Synthesis Recombinant DNA Technology 1 10 27 46 65 85 104 119 137 153 169 185 199 213 227 241 256 269 284 300 315 330 348 Chapter 1 Introduction to Biochemistry 1) Which elements account for more than 97% of the weight of most organisms? A) C, H, N, Mg, O, S B) C, H, N, O, P, S C) C, H, N D) Fe, C, H, O, P E) Ca2+ , K+ , Na+ , Mg 2+ , ClAnswer: B Page Ref: Section 2 2) Proteins in biological membranes may be A) porous. B) attached to the membrane surface. C) span the membrane. D) All of the above E) B and C only Answer: D Page Ref: Section 3 3) Which statement about cellulose is false? A) It is the most abundant polysaccharide in nature. B) Its monomers are joined...
Words: 70772 - Pages: 284
...1. Which of the following is the characteristic of the living thing? A. have specific shape B. have regular shape C. have organized body D. none of the above 2. Which of the followings includes in homeostasis? a. To maintain the shaped of the body b. To maintain the balance of the body c. To maintain the temperature of the body d. To keep the animal away from the body 3. Your hearts starts beating before seven month of your birth. The study of your body at this stage comes within: (a) Morphology (b) Embryology (c) Anatomy (d) Histology 4. A doctor is studying the contraction and relaxation of a heart. He is studying: (a) Morphology (b) Embryology (c) Anatomy (d) Histology 5. Study of different parts of eye is called (a) Histology (b) Anatomy (c) Physiology (d) None of these 6. A biologist removes some bones of dinosaurs from a rock. He is studying: (a) Morphology (b) Paleontology (c) Ecology (d) None of these 7. Darwin sys, “man has formed from monkey”. He talked about (a) Fossil (b) Evolution (c) Taxonomy (d) None of these 8. Kangaroo lives in Australia but buffaloes lives in Pakistan. The study of this distribution of animals is called (a) Ecology (b) Environmental biology (c) Taxonomy (d) Zoogeography 9. The study of structure of molecule of starch is called: (a) Molecular biology (b) Biochemistry (c) Morphology (d) None 10. The study of Amoeba comes with in the branch of biology: (a) Taxonomy (b) Ecology (c) Microbiology (d) None 11. The study...
Words: 18276 - Pages: 74
...NOTE: This PDF document has a handy set of “bookmarks” for it, which are accessible by pressing the Bookmarks tab on the left side of this window. ***************************************************** We are the last. The last generation to be unaugmented. The last generation to be intellectually alone. The last generation to be limited by our bodies. We are the first. The first generation to be augmented. The first generation to be intellectually together. The first generation to be limited only by our imaginations. We stand both before and after, balancing on the razor edge of the Event Horizon of the Singularity. That this sublime juxtapositional tautology has gone unnoticed until now is itself remarkable. We're so exquisitely privileged to be living in this time, to be born right on the precipice of the greatest paradigm shift in human history, the only thing that approaches the importance of that reality is finding like minds that realize the same, and being able to make some connection with them. If these books have influenced you the same way that they have us, we invite your contact at the email addresses listed below. Enjoy, Michael Beight, piman_314@yahoo.com Steven Reddell, cronyx@gmail.com Here are some new links that we’ve found interesting: KurzweilAI.net News articles, essays, and discussion on the latest topics in technology and accelerating intelligence. SingInst.org The Singularity Institute for Artificial Intelligence: think tank devoted to increasing...
Words: 237133 - Pages: 949
