WAEC Biology 2017 Papers

Concept:Both unicellular organisms share a similar body shape, with a blunt anterior region and a pointed posterior region.Explanation:$\textit{Paramecium}$ and $\textit{Euglena}$ are both single-celled organisms.Their body outlines show a clear similarity: the anterior (front) end is blunt or rounded, while the posterior (rear) end is pointed.However, their locomotory structures differ completely.$\textit{Paramecium}$ moves with many tiny hair-like cilia, whereas $\textit{Euglena}$ moves using a single whip-like flagellum.So, the shape of the locomotory organs is not the same, eliminating option A.$\textit{Paramecium}$ possesses both a macronucleus and a micronucleus, but $\textit{Euglena}$ contains only a single nucleus.Therefore, option C is incorrect.In $\textit{Paramecium}$, contractile vacuoles are present at both the anterior and posterior ends, but this is not a feature shared with $\textit{Euglena}$.Thus, option D is also incorrect.The only structural similarity listed is the overall body form: blunt anterior end and pointed posterior end.Answer:Option B — blunt anterior and pointed posterior.