Which statement best describes the relationship between photosynthesis and cellular respiration? Photosynthesis removes carbon from the atmosphere, and cellular respiration releases carbon back into the atmosphere.
Photosynthesis is part of the carbon cycle, and cellular respiration is not.
Only plants perform photosynthesis, and only animals perform cellular respiration.
Photosynthesis releases carbon into the atmosphere, and cellular respiration removes carbon from the atmosphere.

Mass is the amount of matter in an object.  weight is the measurement of the pull of gravity on an object.  say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165)  now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon.  however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant.  in conclusion it is possible for your weight to change as your mass remains constant. 

Dsolubility let me know if you have any other questions for chemistry