JAMB 2014 Biology · Question 25

Which of the following organisms is multicellular?

Options

A.Chlamydomonas
B.Spirogyra
C.Amoeba
D.Euglena

Answer: B. Spirogyra

Explanation written with AI and checked against the answer key

Step 1: Analyze the question We need to find the organism that is made of many cells (multicellular). The others are unicellular (single-celled).

Step 2: Review each option

A. Chlamydomonas: a unicellular green alga with two flagella. It is a single cell.
B. Spirogyra: a filamentous green alga. Its body is a long thread made of many cylindrical cells joined end to end. It has spiral chloroplasts, which give it the name. It is multicellular.
C. Amoeba: a unicellular protozoan that moves with pseudopodia.
D. Euglena: a unicellular organism with a flagellum and chloroplasts. It has features of both plants and animals.

Step 3: Identify the answer Only Spirogyra has a body made of many cells arranged in a filament.

Correct answer: B. Spirogyra

Exam tip: Remember "Spiro = Strings." Spirogyra looks like green slimy strings on ponds. The other three (Chlamydomonas, Amoeba, Euglena) are all single-celled. Note that Chlamydomonas can form colonies in some relatives such as Volvox, but Chlamydomonas itself is unicellular.

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