The EMB (Eosin Methylene Blue) agar is a selective and differential agar medium. It contains sucrose and lactose as fermentable substrates together with Eosin Y and methylene blue dyes which in combination gives the agar its characteristic color when prepared and serves as a pH indicator as well as an inhibitor of growth of Gram-positive bacteria. Hence, it is primarily used to isolate Gram-negative fecal coliforms while some positive fecal coliforms such as Staphylococci are also able to grow.
These coliforms are of two types:
- Lactose or sucrose fermenting coliforms form metallic sheens on the agar as a result of acid production and the response of the indicator to the increased acidity.
- Non-lactose/sucrose fermenters are only able to produce acid by protein deamination. Hence they either form colorless or pinkish colonies on the agar
On the other hand, Mannitol salt agar is a selective and differential agar medium that is primarily used to isolate Staphylococcal bacteria. The presence of sodium chloride in the medium makes it a partial or complete inhibitor of other bacteria.
Hence, an unknown bacterium that forms colorless colonies on EMB will either be a non-lactose fermenting, Gram-negative coliform that will hardly grow on Mannitol salt agar, or a Gram-positive fecal Staphylococcus.
Staphylococci bacteria are of two types:
- Coagulase-positive will form yellow colonies on the Mannitol salt agar.
- Coagulase-negative will form red colonies on the Mannitol salt agar.
More about isolating media can be found here: https://brainly.in/question/7238948
Answer:
C. type of fertilizer because the ferilizer varies in the amount of chemicals they have.
Explanation:
Answer:
a.Most bacteria and fungi are harmless and may be beneficial to other living things.
Explanation:
Bacteria and Fungi are two distinct organisms that belong to different class of organisms. Fungi are eukaryotic while bacteria are prokaryotic. Although they both exist in different life forms such as being parasitic, saprophytic etc. most bacteria and fungi species are harmless and may even be beneficial to other living things.
Bacteria and Fungi are beneficial to other organisms in the sense that they form mutualistic relationships with other living organisms. For example, certain species of bacteria helps to fix nitrogen in the root nodules of leguminous plants, while fungi forms a mutualistic relationship with algae called LICHEN where they benefit one another in a way or the other.
The correct answer is phototrophism.
Phototrophism is said to be the growth of a plant toward a source of light.
It is response to the stimulus of light and is seen when a plant bends towards the direction that light is coming from. Response by plants to a stimulus is called tropism. The word or prefix "photo" means or refers to light. Therefore phototropism simply means response to light.
Phototropism can be especially evident in the jungle where the jungle floor gets very little light. If a tall tree falls to the ground, it leaves a gap in the canopy through which sunlight streams to the ground. Many jungle plants growing on the ground will bend towards the gap and rapidly grow towards the source of light.
Fish live completely in water, amphibians partly in water and land while reptiles live on land. Fish and reptiles have scales while amphibians have smooth skin. Fish breath through gills, amphibians through gills and lungs while reptiles through lungs. They are generally classified as vertebrates.
