(a) What is a cell?
(b) Describe the structure and state the function of each of the following:
(i) Nucleus
(ii) Mitochnodrion.
(c)(i) Make a labelled diagram 8 cm to 10 cm long of the Euglena.
(ii) List. three animal-like features and two plant-like features of Euglena.
Explanation
(a) Cell is the basic and smallest unit of life. It is the functional unit of life, from which all living things are built.
(b) Nucleus has a spherical body which is covered by a double membrane which contains hereditary materials, Chromosomes and genes often centrally located in the cell, embedded in cytoplasm. It contains nucleus and nucleoplasm. The nucleus controls the activities of the cell and initiates cell division.
(ii) Mitochnodrion is oval/rod-shaped. It is bounded by a double membrane. The inner membrane is folded and the interior is filled with matrix. The matrix contains ribosomes. It acts as the site for tissue respiration.
(ii) Animal-like features of Euglena are:
(i) Presence of flagellum (for movement)
(ii) Pellicle (covers the body)
(iii) Contractile vacuole (for Osmoregulation)
(iv) Eye spot (sensitive to light)
(v) Presence of gullet.
Gullet Plant-like features of Euglena are
(i) Chloroplast (for photosynthesis or manufacture of own food) Eye spot
(ii) Paramyium granules/pyrenoids (for storage of starch)