Answer/Explanation:
An important way of selecting for bacteria carrying specific recombinant DNA is to add a resistance gene (such as antibiotic resistance) to your gene of interest. That means that any bacteria that carry your DNA will be resistant to a specific antibiotic (in this case streptomycin). Therefore, you can grow your bacteria on plates with streptomycin, and in theory, the bacteria will be unable to grow if they don't have the resistance gene and your gene of interest.
Here, strain A does not grow on streptomycin plates, but strain B now has 100 colonies. This suggests strain B can grow on streptomycin, meaning it is resistant.
Strain B is therefore the streptomycin resistant master plate strain.
Answer:
A thick, dense fur, keeps the fox warm during winter, by preventing excessive loss of temperature and body heat when it is cold.
Answer: Water, Sunlight, Carbon Dioxide, and oxygen
Explanation: Hope this helps
Fish will eat tadpoles if they can get to them. The only way to stop them would be to give the tadpoles a space that the fish can't get to, like a shallow area with a barrier (plastic mesh would work but make sure the fish can't get caught in it) or lots of plants, or make a separate wildlife pond.
