EVERYDAY SCIENCE

Detailed explanation-1: -Cockroaches have an open circulatory system. They lack blood vessels and capillaries. The blood is present in spaces called hemocoel. The visceral organs bath in the hemocoel.

Detailed explanation-2: -Cockroaches have an open blood vascular system, unlike the circulatory system in earthworms and frogs. It has an elongated tube that serves the function of the heart. It regulates the blood, which we know as haemolymph containing haemocytes and a colourless plasma.

Detailed explanation-3: -Open circulatory system: It is primarily found in invertebrates. Here, the blood flows freely through cavities since there are no vessels to conduct the blood. Closed circulatory system: It is found in vertebrates and a few invertebrates, like earthworms. This system has vessels that conduct blood throughout the body.

Detailed explanation-4: -Note: earthworm is a member of phylum Annelida and has a closed circulatory system while snail is of Mollusca and cockroach falls under Arthropoda. Open circulatory system is a characteristic feature of Arthropoda and Mollusca, not of Annelida.

Detailed explanation-5: -The circulatory system of cockroaches is an open circulatory system because the circulatory fluid does not flow through blood vessels but reaches the tissues directly. The circulatory fluid inside cockroaches is colorless, as it does not contain hemoglobin.