How can there be strong and weak muscle contractions if a single muscle fiber always contracts to its full extent?

How are viruses and bacteria different?

Describe the response the kidneys have to dehydration and excessive water intake. what happens to the concentration of urine in each case ?

Astudent poured a solution of bromothymol blue indicator into three test tubes. then he placed an aquatic plant in two of the test tubes, as shown below. he placed a stopper on each test tube and placed them all in the dark for 24 hours. bromothymol blue turns from blue to yellow in the presence of co2