The organelle you're looking for should be cholorplasts.
Chloroplasts are double membrane bound organelles, which is important for the process so photosynthesis. The outer membrane is smooth and gives the shape of the chloroplast, while the inner membrane forms sac that contains chlorophyll inside.
Chloroplasts exists in green plants that photosynthesize for energy, and they appear the most in mesohpyll cells, a type of cells in leaf.
Annelids have neither an external or an internal shell. Examples of annelids are
earthworms and leeches.
To have the largest sample size also gives you more data, thus increasing the likelihood of accuracy
Yes all organisms display cellular respiration.
