In the diagram below, which step represents the excretory function of the lungs?

a. blood in
b. co2 out
c. o2 in
d. blood out

B. CO2 out

Explanation:

The excretion is the process of removal of the waste product from the body. The carbon dioxide is the byproduct of the aerobic respiration, which is carries from the tissues and the lungs by blood. In the lungs at alveoli, the carbon dioxide is transferred from the blood to the lungs and released out through the nostrils. Hence, the out of the carbon dioxide represent excretion through lungs.

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.