Photosynthesis is an endergonic reaction. why? .

Photosynthesis is an endergonic reaction because it absorbs energy from its surrounding namely, carbohydrates from the water, minerals from the soil, carbon dioxide from the air and sunlight, then releases oxygen as an exergonic reaction once the process is complete.

Photosynthesis is an endergonic reaction because the plants are absorbing light energy. It's not heat energy but it's light energy. So they're absorbing that energy to make new stuff. Photosynthesis cannot happen without adding energy.

organ system-an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.

that is wrong, its not thymus.