Amoeba feeds on microscopic organisms such as single-celled algae and bacteria.
Answer:
Everything at some point belonged to a common ancestor, but these four species are considered to be like this because of similar ancestral traits that have been passed on to generations such a homologous pairs, vestigial structures, they are all mammals, similar amino acid sequences, vertebraes, etc.
The first generation of offspring in Mendel's experiment is called "F1".