Question

Thirteen-chambered tubular heart is found in
A) Cockroach
B) Earthworm
C) Frog
D) Rabbit

Answer 1

Hint:- Most multicellular organisms have a functioning circulatory system. The circulatory system circulates the nutrients, oxygen, and other important components throughout the body. The most important organ of the circulatory system is the heart. The heart pumps blood all over the body. Most vertebrates have haemoglobin present in their blood giving the blood its red colour. The circulatory fluid in arthropods is called hemolymph as it is mixed with interstitial fluid and is colourless.

Complete answer:-
The cockroach has a thirteen- chambered tubular heart, three in its thorax region, and ten in the abdomen. Together thorax and abdomen make thirteen segments. Therefore, each segment has a tubular heart. The hemolymph enters the chambers through the Ostia (opening to the heart). The chambers also have auricular and ventricular valves that regulate the blood flow in and out of it.
Earthworms do not have a heart instead they have well-developed blood vessels. They have two main blood vessels that connect the posterior and anterior ends of the organism. They are called the dorsal and ventral blood vessels. Apart from that, they have supra oesophagal vessels and lateral oesophagal vessels. The dorsal blood vessel also has valves to prevent the backflow of blood.
Frog, an amphibian, has a three-chambered heart. It has two auricles and one ventricle. The blood vessels help in the flow of blood throughout the body.
Like all mammals rabbits have a four-chambered heart, with two auricles and two ventricles. The blood vessels conduct the blood throughout the body.

The correct option is (A). The cockroach has a thirteen chambered tubular heart.

Note:- The heart of the cockroach is present in the pericardial sinus which is one of the divisions of the body cavity.
The first chamber is the largest heart chamber in a cockroach. The blood flows from the posterior chambers to the anterior chambers. From the anterior aorta, the blood flows into the head sinus (cavity), the heart is not present in the head.