Answer:
Chloroplasts are not visible in the onion bulb, only in its leaves and stem.
Explanation:
Chloroplast is an organelle found in the cells of green plants, and in photosynthetic algae, where photosynthesis takes place.
Note that onion bulb do lack chloroplasts because the bulb is usually situated under the ground where light cannot penetrate; so it does not need chloroplasts.
However, the green leaves and stem of an onion plant (the shoot system situated above the ground) are normally exposed to daylight and so have chloroplasts for the production of sugars stored in the bulb, but the onion bulb does not.
In spite of all that has been mentioned, onion contains plant cells not animal cells.