What feature was not present in the first eukaryotes?

Cell walls. Or even mitochondrion

Explanation:

Eukaryotes at first did not have cell walls. They also didn't have mitochondrion. But the answer is probably cell wall.

a. seed plant structure. 1. the three main plant organs are roots, stems, and leaves. a fourth kind of tissue, meristematic tissue, is responsible for plant growth. meristematic tissue is the only plant tissue that produces new cells by mitosis. plants can lose water out of their leaves as they exchange gases with the air

explanation:

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".