9 Meiosis CHAPTER OUTLINe Meiosis (p. 172) 9.1 Discovery of Meiosis (p. 172; Figs. 9.1‚ 9.2) A. In 1882‚ Belgian cytologist Pierre-Joseph van Beneden discovered that the gametes of the roundworm Ascaris contained two chromosomes while somatic cells contained four. B. Fertilization 1. van Beneden proposed in 1887 that an egg and sperm could fuse to form a zygote. 2. The fusion of gametes is called fertilization or syngamy. C. Meiosis 1. A reduction division is required to reduce the number
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1. Bedbugs have been evolving in the United States since the 1940s and 50s. (1) Due to genetic mutations after World War II a widespread of pesticides known to be DDT was used. The genetic variation makes them resistant to the pesticides. (2) These DDT pesticides were used on the bedbug population‚ making them resistant to the pesticide. This illustrates natural selection because those resistant with the pesticide survive best. Which is heritable to their population with the resistant pesticide offspring
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Phylum Mollusca Unit 4 Mollusk Introduction Phylum Mollusca Molluscus = soft Soft-bodied animals that usually have an internal or external shell. Includes snails‚ slugs‚ clams‚ squids‚ and octopi. True coelom Complex‚ interrelated organ systems Body Plan The body plan of most mollusks have 4 main parts: foot 2. mantle 3. shell 4. visceral mass 1. Foot: muscular; may be used for crawling‚ burrowing‚ or tentacles for capturing prey Mantle: thin tissue layer
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Midterm Study Guide Answers 1. A hypothesis is an explanation of observations. “If the floor is wet‚ I will slip.” 2. A controlled experiment is when only one variable is changed. 3. If the plant you are experimenting with has a disease that is an unavoidable experimental error. 4. An enzyme speeds up reactions and lowers the energy it takes to produce something‚ a lock and key. 5. Autotrophs make their own food by producing sugars from sunlight and various chemicals. 6
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Andrew Schwartz 1-19-2011 Assignment 1 * Fish- Channel Catfish‚ May 23‚ 1997. It is slender‚ with a deeply forked tail. The young have spots that fade away with age. It feeds on animal and plant material by using it’s whiskers. * Fossil- Crinoid‚ June 16‚ 1989. It is the mineralization of an animal which has a plant-like appearance‚ so it is known as the “sea lily.” * Mineral- Galena‚ July 21‚ 1967. It is the major source of lead ore. It is dark gray in color and breaks into small
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1. Phospholipid: Molecule that forms a double-layered cell membrane; consists of a glycerol‚ a phosphate group; and two fatty acids. 2. Selectively permeable (Semi): Condition or quality of allowing some‚ but not all‚ materials cross a barrier or membrane. 3. Receptor: Protein that detects a signal molecule and performs an action in response. 4. Diffusion: Movement of dissolved molecules in a fluid or gas from a region of higher concentration to a region of lower concentration. 5. Osmosis: Diffusion
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A. Fermentation Lab- The basic process Prepared 3 beakers with contents listed below. ( a. Beaker 1: glucose only b. Beaker 2: Starch only c. Beaker 3: Starch + amylase). Poured contents of each beaker into its respective fermentation tube‚ ensuring the tail portion of the tube was filled with liquid. Placed tubes in an incubator at 37 degrees‚ measuring distance between tip of tube tail to fluid level at 20‚ 40‚ and 60 minute intervals. Calculated gas volume using this distance along with radius
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5PY017 Pharmaceutical Microbiology Evaluation of antimicrobial effectiveness of disinfectants Abstract A control experiment was performed to rule out the effects of the medium and neutralizer to allow us to see the effect of the disinfectant on the four organisms within a 5 minute range. The bacterial suspension used for paired at different concentration data was Staphylococcus Aureus for which gave good results when the reduction factor value of 1.20x106 ml-1 was obtained for the organism
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A cycle is defined as any complete round or series of occurrences that repeats or is repeated in the same order and at the same intervals. The natural existence of cycles is highly important without cycles resources would run out and organisms would die. The amount of carbon nitrogen and oxygen on the earth is fixed‚ they can exists in different forms but no more may be added. So that these don’t run out they are cycles so they may be reused. Photosynthesis and respiration are the reverse of each
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Microorganisms: * Small living organisms; there are 3 types * Bacteria – ecoli‚ salmonella * Fungi – mushrooms‚ athletes foot * Virus – influenza (flu)‚ HIV * When they enter our body‚ they multiply and release toxins / harmful chemicals into our blood * They duplicate every 20 minutes * Physical barriers: eyelashes prevent MO’s from entering through our eyes‚ nasal hairs reduce them‚ skin is a barrier to them (although they can enter through cuts)‚ chemicals in tears
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