2017 - WAEC Biology Past Questions and Answers - page 1

Porifera are 'pore bearing' organisms, commonly known as sponges, are the only multicellular organisms without a nervous system. Their response to stimuli is by a contraction in their bodies.

The plasmodium is a single-celled parasite that multiplies in red blood cells of humans as well as in the mosquito intestine. Hence, it doesn't live freely.

The production of ATP happens in the mitochondrion, which likewise exists in both animals and plants.

Osmosis is responsible for the ability of plant roots to draw water from the soil. Plants concentrate solutes in their root cells by active transport, and water enters the roots by osmosis.

Euglena use their chloroplasts to produce nutrients through photosynthesis. It is a dual organism as it can act both as an autotroph, making its own food, and heterotroph, feeding on other substances.

The diagram shows the lower arm which can be seen between the elbow and the wrist.

The part II is attached to the humerus. It forms a hinge joint to make up the hand.

The triceps is a large muscle on the back of the upper limb of many vertebrates. The part III is a part of the bone that forms the triceps.

The diagram shows the transverse section of a dicotyledonous stem showing its tissue distribution.