BIO 171 Module 4 Exam Complete Solutions 2024

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BIO 171 Module 4 Exam Growth media - ✔nutrient-rich environment for isolating and culturing microorganisms, includes sugars, amino acids, and vitamins, also called nutrient broth, grows microbes in a suspension Lysogeny broth - ✔most common nutrient broth, can grow a vast array of microbes, plates are yellow, non-selective and non-differential media, commonly used for growing e coli (easily produces recombinant proteins) Selective media - ✔suppress growth of unwanted bacteria and encourage growth of desired microbes, uses limited amounts of nutrients, varying degrees of pH, or various chemical additives like antibiotics that limit microbial growth, often used to grow Neisseria meningitides (fungi and mold outgrow this slow growing bacteria) Differiential media - ✔distinguishes between 2 unrelated microbes, e.g. E coli and salmonella are both gram negative but can be distinguished by the presence of lactose fermentation- e coli ferments lactose and turns the culture red, salmonella doesn't and culture remains white/tan enriched media - ✔contains complex organic substances such as blood, serum, hemoglobin, or special growth factors required by fastidious microbes, used to grow fastidious 2 forms of growth media - ✔liquid and solid solid growth media - ✔housed in a sterile petri dish, liquid growth media with hardening agent added Agar - ✔a gel-like polysaccharide compound used for culturing microbes; extracted from certain red algae, creates a solid smooth surface Colonies - ✔microbial growth in a media, appears as individual isolated dots- isolates merge into one another Lawn - ✔microbial growth of the entire petri dish Agar characteristics - ✔: Outside of the lab you've probably come across the 'cousin' of agar, gelatin. Gelatin is an animal-derived product that gives Jello its classic texture and form. Agar is simply the plant-based form and acts in a very similar way. In both cases, as you increase the amount of agar/gelatin the firmer the composition becomes. The dehydrated agar (and other necessary components) is mixed with water and heated to a high temperature to dissolve the agar into solution. The high temperature also ensures


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