regions of membrane lipids involved in cell signaling are called lipid rafts. • Hopanoids are sterol-like molecules found exclusively in bacteria. • Membranes from cells grown in media enriched with stearate are less fluid than normal membranes. This is because the membranes have more saturated fatty acids. • The functions of the biological membrane are : • They contain receptors for the detection of external signals • They provide a means of cell to cell communication • They regulate movement
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SBI4U Exam Review Topic 1 1. The table below shows the level of hemoglobin measured in two different groups of athletes. Hemoglobin / grams per 100 cm3 Number of athletes tested Standard deviation / grams per 100 cm3 Group A 12.6 200 0.8 Group B 11.9 220 3.2 Which of the following statements is correct? A. Results from group B are more accurate because more athletes were tested. B. Results from group B are more reliable because it has a higher standard deviation. C.
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Stem cells -are biological cells found in all multi cellularorganisms‚ that can divide (throughmitosis) and differentiate into diverse specialized cell types and can self-renew to produce more stem cells. In mammals‚ there are two broad types of stem cells: embryonic stem cells‚ which are isolated from the inner cell mass of blastocysts‚ and adult stem cells‚ which are found in various tissues. In adult organisms‚ stem cells and progenitor cells act as a repair system for the body‚ replenishing
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SPECIALIZED CELL ANIMAL Sperm cells PLANT Xylem cells are specialised to find a female cell (egg cells) and join with it. They have tails‚ that makes them move in water to find and fertilize the female cell. They can move because they have many mitochondria located between the tail and the head‚ which gives them energy. In the head‚ there is a vacuole filled with acrosome‚ which is a specialized Lysosome that releases enzymes in order for the Sperm Cell to break into the Egg Cell‚ through the
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Cell Structure and Function Chapter Outline Cell theory Properties common to all cells Cell size and shape – why are cells so small? Prokaryotic cells Eukaryotic cells Organelles and structure in all eukaryotic cell Organelles in plant cells but not animal Cell junctions History of Cell Theory mid 1600s – Anton van Leeuwenhoek Improved microscope‚ observed many living cells mid 1600s – Robert Hooke Observed many cells including cork cells 1850 – Rudolf Virchow
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Plant cells are eukaryotic cells that differ in several key aspects from the cells of other eukaryotic organisms. Their distinctive features include: A large central vacuole‚ a water-filled volume enclosed by a membrane known as the tonoplast maintains the cell’s turgor‚ controls movement of molecules between the cytosol and sap‚ stores useful material and digests waste proteins and organelles. A cell wall composed of cellulose and hemicellulose‚ pectin and in many cases lignin‚ is secreted by
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7/6/2011 CELL DIVISION CHAPTER 3: CELL DIVISION 3.1 THE CONCEPT OF CELL DIVISION 3.2 THE CELL CYCLE 3.3 MITOSIS 3.4 MEIOSIS Related to the theory of cells Rudolph virchow ; 1855 stated; „Omnis cellula e cellula‟ Every cell is from a cell or “All new cells are derived from other cells” A cell (daughter cell) is originated from another cell ( ) through . In cell division‚ is inherited from one generation to the next. Involve the distribution of genetic material (DNA) to each daughter
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HeLa Cells are Important to Science Henrietta Lacks‚ a poor black woman in the 1950’s‚ unknowingly had samples taken from her cervical cancer specimen and changed science from that point on. Due to the continuous self-reproduction of the cells‚ HeLa cells are the most important cell line ever discovered by scientists to date! Popsci.com gave five reasons of why HeLa cells are so important to society. Popsci.com explained‚ “1. Before HeLa cells‚ scientists spent more time trying to keep cells alive
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Experiment title: Preparation of Biological Materials for Microscopic Examination Objectives: 1. To learn how to use a microscope. 2. To study the cell structure of starch grains‚ onion cells and cheek cells. 3. To differentiate the difference between starch grains‚ onion cells and cheek cells. Introduction: Microscope is an optical instrument use to magnify micro objects that hardly or impossible to be observed by naked eyes‚ so that the objects can be studied. Compound light microscope
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which he called cells’ this in itself unbeknownst to him‚ was the discovery of the fundamental unit of all living things. In 1838 a botanist called Schleiden derived the theory The basic unit of structure and function of all living organisms is the cell.’ Over 150 years later this can be regarded as one of the most familiar and important facts within the biological fields. Drawing of cork cells published by Robert Hooke 1665 The Cell itself and use
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