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Flashcards by jennabarnes12387, updated more than 1 year ago
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Created by jennabarnes12387
about 10 years ago
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| Question | Answer |
| where did the evolution of bacteria occur? | in boiling or near boiling hot springs and without oxygen. mostly in underwater but some land hot springs |
| Describe proteobacteria. Why don't we study it fully in this lab? | named after Proteus the shape shifting sea god, they are divided into 5 groups, alpha thru epsilon. we dont cover it fully becuase the group is to diverse and large as well as the only way to identify them is they are gram negative. |
| Alpha proteobacteria is a smaller subgroup of Proteobacteria. How are they related to eukaryotic cells | closely associate with eukaryotes as it is believed that eukaryotic mitochondria we once proteobacteria that was involved in a symbiotic relationship with a primitive cells |
| Why are Rhizobium bacterium important? How do they interact with plants? | Nitrogen is very important in living organisms but the triple bonds in nitrogen gos found in the air make it so most organsims cant use it. This bacteria forms a symmbiotic relationship with legum plants like beans and peas. the bacteria fies nitrogen for the plant ant the plant gives the bacteria nutrients and vitamins. the relationship is very specific. |
| in this lab we use an oxidative stain called Janus green in a eukaryotic cell called a paramecium. how does the dye work? | the dye turned blueish green when its in the presence of oxidation reactions like the ones that occur in the mitochondria of eukaryotic cells. this allows us to seethe mitochondria of the cell under a microscope more easily |
| the legume root should have what kind of bacteria? | nitrogen fixing bacteria, Rhizobium |
| When looking at the legume root undera microscope you should see a faint pink colour. What causes it? | leghemoglobin, a type of hemoglobin which regulates the oxygen sensitive nitrogen fixation rection by keep oxygen levels down |
| What dye do we use on the legume root? | methylene blue |
| Gram positive bacteria stain purple. Why? | they have a thicker wall of peptidoglycan which holds the crystal violet stain |
| Gram negative cells dye red. Why? | they don't have much peptidoglycan so the crystal violet stain rinse out. When they are dipped in the counter stain, they hold the red colour |
| gram positive bacteria are found where? | in cultured foods like cheese and yogurt |
| What are firmicutes? | harmless bacteria found on our skin. an example is staphylococcus epidermidis |
| what are actinobacteria? | a kind of gram positive bacteria and are found in soil and fresh and marine water. also in plants and the gastrointestinal tract of some animals. they are decomposes in the soil and breaking down cellulose and chitin that would not be broken down otherwise. used to make antibiotics and involved in the smell and flavor of strong smelling cheeses. they can sometimes cause acne on the skin but usually are harmless. also break down sloughed off skin on feet, giving off a smell that we know as foot odour. |
| What are cyanobacteria? | they are gram negative, photosynthetic bacteria that is sometimes referred to as blue-green algae. they are found in water and sometimes in the fur of mammals. they are single celled |
| What are Anabaena? | a type of nitrogen-fixing cyanobacteria. their filaments are made of barrel shaped cells in a gel, giving it a beaded appearance |
| What are nostoc? | also a filamentous cyanobacteria like anabaena. they form colonies that look like nasal mucus. |
| what are spirochetes? | spiral shaped mobile bacteria that live in digestive systems of some animals are found in dental plaque. some cause Lyme disease |
| what are biofilms? | a community of microbes that attach to surfaces with an adhesive matrix. they are highly symbiotic and many organisms in them rely on eachother. sometimes they can share genetic information. respnsible for the development of some medical implants and contact lenses. dental plaque is an example of a biofilm. |
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