Answer:
A
Explanation:
At the start of a drought, groundwater may not be noticeably lower (not B). Only aquifers near the ocean may become contaminated with salt water (not C). And it is definitely not D.
Answer:
The correct answer is- phosphorus and sulfur
Explanation:
Hershey and Chase used radioactive phosphorus and sulfur to label T2 bacteriophage. Then they infected E.coli with these bacteriophage labeled with radioactive phosphorus and sulfur.
After infection, they centrifuge the cell and found that radioactive phosphorus is present in the bottom and radioactive sulfur in supernatant . As sulfur is mostly the part of protein not DNA and is found in supernatant and phosphorus is mostly present in DNA not protein which was found in cell debris, therefore, it was proved that DNA is the genetic material.
Answer:
<u><em>Galapagos finches</em></u><u> have various beak sizes that make foraging for food more successful.</u>
Explanation:
Organisms evolve over time due to changes in their genome. These are pontaneous, and occur in DNA at random. These changes are called mutations and form alleles or different forms of a gene.
Over time within a population, the number alleles increase the variation of the population. These variants may confer specific traits within an individual, that may confer a biological advantage.
Thus, the trait may make the organisms more capable of obtaining food, shelter a mate etc. or ensure survival, i.e. they are able to pass on their genes to the next generation.
Their beaks could have adapted over time to help them better survive in their environment.
