The feature of reproduction common to Amoeba, Spirogyra, and Yeast is that they a) reproduce asexually.
Explanation:
Amoeba, Spirogyra, and Yeast all reproduce asexually. Asexual reproduction means they create offspring without the involvement of gametes or fertilization. This is in contrast to sexual reproduction, which requires the fusion of gametes.
Why other options are incorrect:
b) they are all unicellular: While Amoeba is unicellular, Spirogyra is multicellular. Yeast can exist as both unicellular and multicellular depending on the environment. Therefore, “they are all unicellular” is not a correct answer.
c) they reproduce only sexually: This is incorrect. All three organisms reproduce asexually.
d) they are all multicellular: This is incorrect. Spirogyra is multicellular, while Amoeba and Yeast are typically unicellular.