Question 1
What structure is required for an organism to be classified as a photoautotroph?

The structure is chloroplast.

Explanation: Photoautotrophs are organisms that can synthesize food using light energy and carbon dioxide via photosynthesis.

Photoautotroph is a combination of two words: photo which means light and autotroph which means an organism that can manufacture its own food.

A photoautotroph manufactures its own food in a process known as photosynthesis. Photosynthesis is a process by which plants manufacture organic foods such as glucose using light energy, carbon dioxide and water. This process takes place in the chloroplast. A chloroplast is an organelle found in plant cells that contains chlorophyll which is the pigment that absorbs the light used in photosynthesis.

the speed increase from w to x due to increased gravity force

the speed decreases from x to y due to decrease in gravity

"d.) carbon dioxide and hydrogen sulfide"