The answer is <span>Time is the independent variable, and the number of birds is the dependent variable. </span>
<span>An independent variable is variable that is not affected in the experiment. It is what experimenter controls. On the other side, a dependent variable is called dependent because it depends on the independent variables. It is what is affected during the experiment.
In Sam investigation, he controls time - he counts birds at 6 a.m. and 6 p.m. So, time is the independent variable. The number of birds is affected during the experiment, so it must be the dependent variable.
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The correct answer is option 4, that is, muscle cells require more energy, so they have more mitochondria in comparison to the skin cells.
Mitochondria are the powerhouse of the cells. The synthesis of ATP takes place in them, that is, the energy currencies of the cell. The cells of the muscles need to work hard and thus require ample energy, for this, they need more concentration of mitochondria to generate a high energy yielding ATPs.
Answer:
The "X" or "Y" gene that determines whether you will be a boy or a girl is an example of a chromosome .
Explanation: