Spontaneous Generation and Cell Theory 1. Tradition thought is very hard to overcome- even with solid evidence to support new ideas * Social pressure has effect on acceptance of scientific ideas and technological advancements * Science is a social/political enterprise * New ideas often met with resistance * Sometimes ostracisms‚ persecution‚ death * Microscope helped to overturn some strange ideas * Disease processes * "spontaneous
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Cheek cell practical Task 2 Risk assessment HAZARD RISK MITIGATION Methylene blue stains wear apron/gloves Swab stick spreading bacteria dispose correctly Microscope slide break/cut skin handle with care Cover slide break/cut skin handle with care Microscope drop/fall on foot position carefully
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Cells must move materials through membranes and throughout cytoplasm in order to maintain homoeostasis. The movement is regulated because cellular membranes‚ including the plasma and organelle membranes‚ are selectively permeable[1]. The purpose of an automatic flow of molecules is to create equilibrium on each side of the membrane. In order for molecules to pass through the membranes‚ there must be pores. The size of the pore determines what molecules can cross. Due to the size and polarity‚ only
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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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Give reasons (s) 1- Formaline is used as fixative in preparation for LM examinations 2- Resolution power is difference from magnification power Complete 1- The cells are the smallest …… and …… units in the body. 2- The size of tissue sample for histological preparation is …… in light microscope and ……. in electron microscope. 3- Fixative used in tissue preparation for LM examination is …….. while in EM is …….. 4- Substance used for tissue embedding in preparation for LM examination is
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Biology – Assignment One Cells. Question One Explain the roles of the main components and features of a cell to the cell function. A typical animal cell is rounded in shape‚ surrounded by a cell membrane. This holds in the cytoplasm‚ which contains other structures such as the nucleus‚ ribosomes‚ and mitochondria. Each cell has tiny structures inside called organelles; each type of organelle performs a particular function. For example there are mitochondria (power stations)‚ ribosomes (protein
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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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Stem cells Nowadays‚ stem cells are the hottest topic in the medical field. More and more researches are performed to investigate these mystic cells. In order to go deeper into this topic and fully understand it‚ let’s first take a look at the stem cells themselves‚ their origins and characteristics which make them so unique and crucial for the medical field. Stem cells are very complex and complicated‚ and‚ that is why‚ it takes a lot amount of time to get to the bottom of their structure to be
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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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8 themes of biology relating to the cell membrane Science as a process: Science is a process which encompasses many methods in order to reach a final conclusion. This relates to the cell membrane because it carries out many processes to reach a final product. For example‚ the cell membrane forms a barrier between the inside of the cell and the outside‚ so that the chemical environments on the two sides can be different. The cell controls those differences to optimize the working of the organelles
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