B looks like the best to me
Cross over is the first way genes are shuffled to give rise to genetic diversity. Cross over takes place in sexual reproduction. The normal way that cross over occurs is chromosomes line up side by side and break off pieces of themselves, then trade those pieces with each other.
If they break the pieces at the same locus in the sequence of base pairs, the result is an exchange of genes called genetic recombination and it ensures that the daughter cells produced have a different genetic makeup from the parent cell and thus diversity occurs.
The reason why nost scientists thought that the first true cells formed on Earth were anaerobic is being shown in the second option :B. because there was no oxygen on early Earth. Paying attention to this fact scientists discovered that first cells were prokaryotes and greatest part of them created oxygen as a toxic by-product of their own metabolism which make them understand how the planet was provided with oxygen and made a conclusion that first cells were anaerobic.
Answer:
"Yes" The streak plate method is very effective in diluting the population size in all 4 plates.
Explanation:
The streak plate method is effective because it is one among the rapid isolation method which further allows for easy observation of the bacteria. This method is also being used for getting the color of the certain substances. Its main principle is to isolate the specific bacteria from the sample of various microbes. It dilutes the microbes number and often reduces their density. It is useful in separation of organisms from the group. These are isolated in the agar plate.
