Answer is (E) : Amino acids (and thus proteins) also have nitrogen atoms; thus, the radioactivity would not distinguish between DNA and proteins.
Let me explain you why. Hershey and Chase conducted their experiment to show what is the genetic material that passes from one generation to another generation. Is it protein or DNA? For explaining this, they allowed the virus to grow in the presence of two different radio active elements.
In one set they grew viruses in the presence of P-32 radio-active element
In another set they grew viruses in the presence of S-35 radio active element.
The reason why they choose these two radio-active element was, phosphorus is present in DNA but not in proteins and similarly sulphur is found in proteins but not DNA.
These viruses were allowed to infect bacteria and the later was observed to be radio-actively labelled with P-32 but not S-35. This clearly showed that DNA is the genetic material which was passed from virus to bacteria.
Now if you choose Nitrogen for labeling, it won't help you in getting any conclusion since nitrogen is present in both proteins and DNA.
Answer:
Paranthropus robustus
Explanation:
2.5 million years ago some autralopithecines were identified by dating fossils from South Africa, meaning they lived a good period of time. Of these, Australopithecus africanus is well known and is a little closer to our species. Other fossils found in excavations in both southern Africa and eastern Africa have been found to be of more recent specimens 2.5 to 2 million years ago. These specimens were classified as Paranthropus robustus and Paranthropus boisei. These australopithecine species became extinct and left no current descendants.
I believe the answer you are looking for is a cell cavity. Also known as: Cavity of cell, or cell space
