WAEC - Biology (2000 - No. 2)
Which of the following best describes a colony of volvox?
Asexually reproduced cells held together in a mass, but independent of each other
Sexually reproduced cells held together in a mass, and dependent on each other
Single free-living acellular units irrespective of their parental origin
Several units of cells, held together by cytoplasmic strands and dependent on each other
Giải thích
Living cells exist in a variety of forms, including Singly or free-living, filamentous and Colonial.
A Volvox colony is made up of thousands of small biflagellate somatic cells arranged in a peripheral layer and embedded in a transparent extracellular matrix (ECM). Volvox can reproduce asexually by forming daughter colonies that are identical to the parent colony. These daughter colonies form inside the parent colony and eventually burst out, killing the parent colony. Consequently, asexually reproduced cells held together in a mass, but independent of each other, explains a colony of Volvox.