Which of the following helps explain why fungi are now classified in a separate kingdom from plants?

A. The cells of fungi are not surrounded by cell walls
B. Fungi are heterotrophs that cannot make food by photosynthesis
C. The cells of fungi do not contain a nucleus
D. All fungi are unicellular, but plants are multicellular

I put A as my response

That's a good attempt, but the correct answer is actually B. Fungi are classified in a separate kingdom from plants because they are heterotrophs, which means they cannot make their own food through photosynthesis like plants do. Instead, fungi obtain nutrients by absorbing them from their environment or by breaking down organic matter. This is a fundamental difference that distinguishes them from plants, which are autotrophs capable of producing their own food through photosynthesis.

To arrive at this answer, it is important to understand the key characteristics that differentiate fungi from plants. By considering the options provided, you can eliminate options C and D, as they are incorrect statements. Option C suggests that the cells of fungi do not contain a nucleus, which is not true. Fungi, like all other eukaryotic organisms, have cells that contain a nucleus. Option D suggests that all fungi are unicellular, but plants are multicellular. This is also inaccurate, as both fungi and plants can exist in either a unicellular or multicellular form.

Option A, which states that the cells of fungi are not surrounded by cell walls, is a characteristic that does differentiate fungi from plants. However, it is not the primary reason for their separate classification. The presence of cell walls is a shared characteristic between fungi and plants, as both groups have cells that possess cell walls. Therefore, option A does not provide the most accurate explanation for why fungi are classified in a separate kingdom from plants.