I believe it is convergent evolution
Answer:
Bacteriophages (phages) are viruses that infect only bacteria and do not infect mammalian or plant cells. Phages are ubiquitous in the environment. Phages or bacteriophages were chosen as a model system for their simplicity, as they only contained protein-coated nucleic acid. Alfred D. Hershey and Martha Chase (who were part of the bacteriophage group) in 1952 studying the infection of the bacterium Escherichia coli by the T2 phage show that the information definitely resides in the DNA. They used phage with either [32P] -labeled DNA or [35S] -labeled proteins to infect the bacteria. Immediately afterwards, they centrifuged the sample so that the infected bacteria remain in the pellet and the virus capsids (proteins) remain in the supernatant. [35S] is found in the supernatant, whereas [32P] is found in bacteria. After one cycle of infection, it was observed that when phage labeled in the [35S] proteins were used, only 1% of the radioactivity was incorporated into the progeny. But when phages were [32P] labeled, more than 30% of the radioactivity was in the progeny. They showed directly that what is transmitted from one progeny to another is the DNA and not the proteins, despite having first "diluted" in a bacterium.
Explanation:
Bacteriophages are viruses that infect bacteria in a specific way. Bacteriophages, like other known viruses, are found in an intermediate zone between living organisms and inert matter. Bacteriophages bind to the host pathogenic bacterium, introduce their genetic material, replicate inside it and destroy it. Hersey, along with his assistant Martha Chase, used phages because they knew that T2 phages were made up of 50% proteins and 50% nucleic acids and that phages entered bacteria and reproduced. As the progeny carried the same infection traits, the genetic material of this had to be transmitted to the offspring, but the mechanism was unknown. These scientists carried out an experimental work with the T2 virus, a bacteriophage that infects the bacterium Escherichia coli, which it reproduces by attaching itself to the outer wall of the bacterium, injecting its DNA into it where it replicates and directs the synthesis of the phage's own proteins. Phage DNA is encapsulated within proteins and produces phages, which lyse or disrupt the cell and release phage from progeny. They infected a culture of bacteria with radioactively labeled phages: the protein coat with sulfur (35S) and its DNA with phosphorus (32P). After infection, they separated the phages from the bacteria by violent shaking using a mixer (hence the name of the experiment). By centrifugation the much smaller phages remained in the supernatant and the much larger bacteria in the pellet. 85% of the radioactivity corresponding to DNA appeared in the pellet and 82% of the protein in the supernatant. This result supported the idea that DNA was the only component of the bacteriophage that penetrated the interior of the bacteria and, having the ability to form new phages, constituted the genetic material.
If a portion of the grass was destroyed by wildfire, then the population of bison that feed on the grass will decrease. This is because there would be very little grass left for them to eat, and they don't eat anything else.
Animalia is the label that appears to differentiate animals from organisms on other kingdom.
Explanation:
Scientists uses the process called taxonomy to classify the organisms based on their structure, functions and relationship to other organisms.
Eukaryotes represents the domain of life. Domain Eukarya are classified into four kingdoms they are protista, fungi, plantae and animalia.
The kingdom protista represents the organisms that are simple structured and they swim through the water and obtain nutrients from the environment.
In the kingdom fungi like mushrooms absorb nutrients from the environment and they are heterotrophs.
In the plantae kingdom the organisms are plants and they are autotrophs. They prepare their own food.
In Animalia kingdom the organisms are animals and they are multicellular heterotrophs. They do not have cell walls and the reproduction is done sexually and some can reproduce asexual.
Answer:
<h2> After one round: one strand of DNA will contain radioactive 3232P, while the other strand will not contain any radioactive phosphate.
</h2><h2> After two rounds: here 50% of DNA will have 3232P in both strands, while 50% will contain 3232P in one strand and nonradioactive in the other strand.
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Explanation:
1. In the initial sample which is immediately removed after addition of radioactive isotope of phosphorus ( 3232P), hence there is no incorporation of 3232P into the DNA because replication in the medium containing 3232P has not yet occurred.
2. After one round of replication in radioactive isotope of phosphorus ( 3232P) containing medium, here only one newly synthesized strand of DNA molecule will contain 3232P, while the other strand will not contain any radioactive isotope of phosphorus ( 3232P), because DNA replication occurs in semi-conservative way.
3. After two rounds of replication in medium which contains radioactive isotope of phosphorus ( 3232P), here 50% of the DNA molecules will have radioactive isotope 3232P in both strands, while the rest 50% will contain 3232P in only one strand and nonradioactive phosphorous in the other strand.
