CELL THEORY – STEM CELLS Stem cells are a large focus of study in today’s biomedical world. “They are cells that exist in an undifferentiated state‚ and transform into differing tissue types depending on what the cells surrounding them are‚“ (National Institute of Health‚ 2012). Stem cells have the remarkable potential to develop into many different cell types in the body during early life and growth. In addition‚ they also serve as an internal repair mechanism inside many tissues‚ dividing without
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Science 9-Biology Observing Cell Division Lab Purpose: To use the microscope to observe and sketch plant cells and animal cells in various stages of the cell cycle. Equipment and Materials: Compound Microscope Laptops Prepared Slide of Onion (Allium) Root Tips Prepared Slide of Whitefish Mitosis BC Science 9 Text pg. 162-163 Part 1-Plant Cells Procedure: 1. Take a prepared slide of an onion tip root and observe it under low power
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Exercise 1: Cell Transport Mechanisms and Permeability: Activity 1: Simulating Dialysis (Simple Diffusion) Lab Report Pre-lab Quiz Results You have not completed the Pre-lab Quiz. 09/20/11 page 1 Experiment Results Predict Question: Predict Question 1: The molecular weight of urea is 60.07. Do you think urea will diffuse through the 20 MWCO membrane? Your answer : c. No‚ not at all. Predict Question 2: Recall that glucose is a monosaccharide‚ albumin is a protein with 607 amino acids‚ and
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1.A) Two main forms of cells exist: eukaryotic cells and prokaryotic cells. Prokaryotic cells are smaller and do not have membrane-bound nucleus or membrane- bound organelles‚ but do have: plasma membrane‚ cytosol and cytoplasm‚ and ribosomes. Prokaryotes contain much less DNA than eukaryotes and have circular chromosomes. Eukaryotic cells have information processing organelles‚ such as the nucleus which houses most of the cell’s DNA‚ and ribosomes which use information from DNA to produce proteins
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Roots The root system of a flowering plant begins its development from the hypocotyl of the embryo of the seed which gives rise to the primary root. Roots generally grow downwards into the soil (positively geotropic) and upwards (negatively geotropic). Roots do not bear leaves and therefore no nodes are present.Two kinds of root systems can be distinguished in flowering plants: tap root systems and adventitious root systems. Usually dicotyledons posses tap root systems and monocotyledons adventitious
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USE OF ONION ROOT TIPS FOR MITOTIC DIVISION OBSERVATIONS Introduction The zone of cell division on the onion root tip is a great place to observe mitotic cell divisions. Through the observation and comparison of different regions of the root tip‚ the duration of mitotic stages and mitotic indexes are determined for the various divisions of the root tip. Methods Each group used a compound microscope to analyze the different sections of the onion root tip. The root tip was visually
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CHAPTER 36 PLANT CELLS The first barrier to form between daughter cells is the middle lamella. Daughter cells expand to their final size and make polysaccharides for a primary wall. After expansion stops waterproofing materials are added for a secondary wall. Water and dissolved materials move from cell to cell by way of pit pairs. A pit is a thin spot in the primary wall where the secondary wall is absent or separated from the primary wall by a space. Strands of cytoplasm called
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Roots of the Cold War I. Growing Distrust 1. FDR‚ Churchill and Stalin met at a Soviet Union resort called Yalta. Stalin promised that he would hold free elections in parts of Eastern Europe under his control. 2. Instead‚ Stalin set of Communist governments in the nations. He wanted a ring of friendly countries to protect the Soviet Union’s southern border. With this‚ Stalin hoped that the Soviet Union would become the world’s dominant power. 3. By 1948‚ most of the countries in Eastern
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Review Sheet Exercise 1 Cell Transport Mechanisms and Permeability Activity 1: Simulating Dialysis (Simple Diffusion) • Describe two variables that affect the rate of diffusion: Two variables that affect the rate of diffusion are size and concentration gradient. The molecular size vs the MWCO size of the membrane can either increase‚ decrease‚ or prevent diffusion. The greater the concentration gradient the greater the diffusion rate due to molecules moving from areas of higher concentration
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PLANT CELL Introduction Plant cell is the basic unit of structure and function in nearly all plants. The range of specialization and the character of association of plant cells are very wide. In the simplest plant forms a single cell constitutes a whole organism and carries out all the life functions. In just slightly more complex forms‚ cells are associated structurally‚ but each cell appears to carry out the fundamental life functions‚ although certain ones may be specialized
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