Answer:
This question is asking to identify the variable in the experimental statement.
The eye chart is the CONTROL VARIABLE
Explanation:
An experiment consists of several variables to look out for in order to achieve any significant result. These variables are independent variables, dependent variables and control variables. Although independent and dependent variables are the major experimental variables, but control variables are also important.
A control variable is the variable that remains constant or unchanged throughout the experiment. Any change to the control variable will affect the dependent and independent variables. In this question, the eye chart is the CONTROL VARIABLE because it remains constant or unchanged. The same eye chart is used for the experiment.
N.B: The distance to the eye chart is the independent variable while the number of letters visible on the line is the dependent variable. Hence, changing the eye chart (control variable) will affect the distance and the number of letters visible.
Continual questioning of observations.
Explanation:
Compare and contrast a frameshift mutation and a single nucleotide substitution mutation in a DNA sequence encoding a protein. How many nucleotides would be inserted or deleted in each? How many amino acids in the protein sequence would be altered in each?
Answer:
At sea level, air pressure is greatest because it is caused by the weight of the entire column of atmosphere at that altitude over that location. As altitude increases, the column of atmosphere gets shorter, and so less weight is pressing down at a given altitude, so atmospheric pressure is reduced.