Answer:
In biology, a molecular clock can be described as a method to determine the time for the divergence of species which occurred by the process of evolution.
Explanation:
The mutation rates of different molecules are used in this method. The mutation rates for DNA sequences and amino acid sequences are usually considered. The molecular clock can be used to compare and estimate the splitting of a lineage. For example, by this method, one can interpret when the chimpanzees and humans diverged from each other.
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-Toshino
D, think of it like a house.
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.
The complete statement made by Stephen Hawking is: "though much of its behaviour through out history, has been pretty stupid, and not calculated to aid the survival of the species."
If one looks at our history, there are some events that defy our capacity for logical thinking. One would think that, as we possess this capacity, we would be able to direct our decisions towards the survival of the human species.
However, in many cases greed and the desire for personal gain have taken precedence. One good example was the burning of the great library of Alexandria, one of the most significant libraries in the ancient world. This magnificent collection was lost during the siege of Alexandria, when Julius Caesar set on fire the ships in the harbor.
Another example is the atomic bomb, when science has been used to invent one of the most destructive weapons known to us. Atomic warfare is still a threat that may end all life on Earth.
Furthermore, the greed of some corporations has led to multiple ecological catastrophes that endanger not only other species but our own future as well. One example is the Bhopal gas leak in India, where in 1984, due to poor maintenance, the chemical plant released 30 metric tons of methyl isocyanite into the atmosphere.
