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:
natural barriers
Explanation:
skin, mucous membrane, tears, earwax, muscus, stomach acid
"The principle of superposition states that the oldest sedimentary rock units are at the bottom, and the youngest are at the top."
Oldest to youngest: Layer B, Layer C, Layer A
The oldest is always at the bottom, the youngest layer is at the top
Answer:
Hello!!! Princess Sakura here ^^
Explanation:
The sun, earth, and moon are held together by gravity, and they interact in lots of ways. The moon orbits the earth because of the pull of the earth. The tides are another interaction in the sun, earth, and the moon system. The tides happen because the moon and sun pull on the oceans, causing them to rise and fall each day.
Answer: option B) Sympatric speciation is best described as a random event that disrupts the allele frequencies in a population
Explanation:
Sympatric speciation is an event/situation whereby organisms of the same species:
- live in the same territory or nearby territories ( i.e do not live in geographical isolation)
- DO NOT interbreed, but select a sexual mate from a much diverse territory to yield new species or offsprings.
This sexual selection then results in generations of offsprings that are genetically different from the rest of the same species due to uneven gene flow or disruption of alleles among the population of same species.
Thus, only option B is true.
