1. This scenario is controlled due to the fact that they usually <span>test the effect of fertilizer, water and sunlight. Two last points pose as explanation for the second part of question.
2. It </span>can not be considered a theory because often it is supported by <span> hypothesis, so it's not direct thesis.
3. The way to know </span>that the y-axis is measuring the growth of the plant is to look at the graph and see that it <span>shows plant growing up.</span>
Hi,
Harshey and Chase did a great experimentation which was basically a two step experiment to prove that DNA and not proteins are the actual carriers of genetic information from parents to offspring.
- In the first part of their experiment, they used bacteriophages (virus that eat bacteria). They used radioactively labeled sulphur(35S) medium to grow bacteriophages and observed that all the bacteriophages had proteins with radioactive sulphur(35S).
- In the next step they allowed these phages to infect bacteria and to their surprise, they found that the bacteria did not had radioactively labeled sulphur in them because the coat of bacteriophage stays outside the body of bacteria when it attacks it. This proved that DNA not proteins were the hereditary material.
- To make their results more reliable, they did a second experimentation in which, they marked the DNA of the phage with radioactive phosphorus 32P. After labeling DNA, they repeated the same experiment and this time, they found radioactive phosphorus inside the bacteria.
<em>This meant that the bacteria had DNA of phage entered inside them and this again proved that DNA not proteins are the hereditary material. You can see attached image for better understanding.
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Hope it help!
Cells Can Replicate Their DNA Precisely. Replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. DNAreplication is one of the most basicprocesses that occurs within a cell.
It has a dorsal nerve chord
<span>A cross-sectional study examines all of the participants at one time. So for a cross-sectional study of cancer survivors, we would gather some sample of former patients and find out how long they have been in remission.
The problem with that cross-sectional design is we would be missing the people whose cancer had returned and caused them to die before our experiment started; we would have introduced a problem called "survivor bias" by only counting people who were STILL in remission and still alive.
A better experiment will use a longitudinal design of enrolling people whose cancer has just gone into remission, and following them to see how long they stay healthy.</span>