I think it’s organism since it already stated skeletal and respiratory then it means it cannot be tissue or organ because skeletal is included so i say go for organism
A good topic idea that could be used can be about ecosystems. Such as how geographic area, plants, animals, weather and landscape make up the types of organisms in that specific ecosystem.
The history of the domesticated sheep goes back to between 11000 and 9000 BC, and the domestication of the wild mouflon in ancient Mesopotamia. Sheep are among the first animals to have been domesticated by humans, and there is evidence of sheep farming in Iranian statuary dating to that time period.
Charles Wilson Peale I believe.