What of the following describes how an organism responds to external stimuli

a. the human body reduces sweating when it's water levels are low

b. a dog eats food when it is hungry

c. a person yawns when oxygen is low in the lungs

d. blinking occurs when dust hits the human eye

Cells are adapted to preform specific functions. which of the following terms refers to this capability?

Hemoglobin is a proton that carries oxygen around the body what is hemoglobin made from

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