Why do animal cells have mitochondria but no chloroplast?

Because they do NOT Photosyntetize, chloroplast capture luminous energy from the sun, on the other hand the animal cells get ATP (Energy) from various process like Krebs Cycle Glucolisis And Electron Transference

Both plant cells and animal cells have mitochondria. But animal cells don't need chloroplasts because they don't go through photosynthesis. The chloroplasts turns sun's energy into a plant cell's food. Animal cells don't go through photosythesis because animals eat other living beings and the animal cells simply break down the food.