1. Laboratory work 1 Theme: Features of the structure of the cephalothorax on the example of the lancelet The purpose of the lesson: To determine the systematic position and study the appearance and internal organs of the lancelet.

2. SYSTEMATIC POSITION OF THE OBJECT Phylum Chordata Subphylum Acrania Class Cephalochordata Order Amphioxiformes Family Branchiostomidae Representative Lancelet, Branchiostoma lanceolatum Pallas, 1774

3. MATERIAL AND EQUIPMENT For one or two students are needed: 1. Preparation of a whole lancelet lying on its side on a glass slide, coated and colored with carmine. 2. Preparation of a transverse incision of the lancelet in the pharynx area. 3. Preparation of cross section of lancelet in the intestinal region. 4. Tripod magnifier. 5. Microscope.

4. THE TASK Consider the appearance of a fixed lancelet, and then under a magnifying glass and microscope - the structure of the systems of its organs. Each student in his album must make the following pictures: 1. Whole lancelet (side view) with organ systems (loupe). 2. A transverse incision of the lancelet in the pharyngeal region (microscope). 3. A transverse incision of the lancelet in the intestine area (microscope).