Differentiate between a diploblastic and a triploblastic animal.
Diploblastic |
Triploblastic |
Animals in which the cells are arranged in two embryonic layers, external ectoderm and internal endoderm. |
Animals in which the developing embryo has a third germinal layer, i.e. mesoderm, between the ectoderm and the endoderm. |
Example: Porifera. |
Example: Platyhelminthes. |
Which of the following is not correct?
(a) Robert Brown discovered the cell.
(b) Schleiden and Schwann formulated the cell theory.
(c) Virchow explained that cells are formed from pre-existing cells.
(d) A unicellular organism carries out its life activities within a single cell.
Define a taxon. Give some examples of taxa at different hierarchical levels.