JAMB Biology Past Questions & Answers - Page 89

Modern cnidarians are generally classified into four main classes: sessile Anthozoa (sea anemones, corals, sea pens); swimming Scyphozoa (jellyfish) and Cubozoa (box jellies); and Hydrozoa

Turbellaria are one of the traditional sub-divisions of the phylum Platyhelminthes (flatworms).

On the 21st day of incubation the chick finishes its escape from the shell. The initial break in the shell is made by the egg tooth. This is referred to as external pipping.

Osmoregulation: Paramecium and amoeba live in fresh water. Their cytoplasm contains a greater concentration of solutes than their surroundings and so they absorb water by osmosis. The excess water is collected into a contractile vacuole which swells and finally expels water through an opening in the cell membrane.

Excretion of water in Paramecium is carried out by the Contractile vacuoles.

A pith is composed of soft, spongy parenchyma cells, which store and transport nutrients throughout the plant. 

Blood plasma is a yellowish liquid component of blood that normally holds the blood cells in suspension; this makes plasma the extracellular matrix of blood cells. It makes up about 55% of the body's total blood volume.

Blood plasma is a light yellow liquid, similar to the color of straw. Along with water, plasma carries salts and enzymes. The primary purpose of plasma is to transport nutrients, hormones, and proteins to the parts of the body that need it.