It was used till the 1960s. Hope i helped.
Answer:
All animals alike as heterotrophs beacuse animals cannot prepare their own food.
Explanation:
Heterotrophs may be defined as the organisms that will depend upon plants or other animals for their food. They are unable to synthesize their own food.
All animals are heterotrophs as they depends on the other organisms for the production of food. All animals are also referred as consumers.
If a mutation occurs in the gametes it will most likely be transferred to the offspring
The upper atmosphere absorbs nitrogen
