CBSE Questions for Class 11 Medical Biology Structural Organisation In Animals Quiz 10 - MCQExams.com

In the given diagram, it represents the earthworm’s dorsal vessel. The earthworm has a closed vascular system with blood vessels. The dorsal vessel in the first thirteen segments acts as a distributing vessel and extends up to the cerebral ganglion. It gives off branches that supply blood to the anterior regions of the body.

So, the correct answer is ‘dorsal vessel’. The correct option is B.

[a] In rats, the right kidney is slightly higher than the left one due to the presence of liver on the right side and so, statement A is incorrect.

[b] Cockroaches possess ten pairs of spiracles, two thoracics, and eight abdominal. So, option b is correct.

[c] The alimentary canal of the earthworm is a straight tube throughout the length of the body consisting of (in the sequence), mouth and buccal chamber, pharynx, oesophagus, gizzard, stomach, intestine, and anus. So, option C is incorrect.

[d] The body of a frog is divisible into head and trunk and so, statement D is incorrect.

Therefore, the correct answer is option B.

Order and path of blood flow from the ventral to dorsal blood vessels is

1.     Ventrointestinal blood vessel

2.     External intestinal plexus

3.     Internal intestinal plexus

4.    Dorsointestinal blood vessels

In the above figure of the circulatory system of Pheretima or Earthworm,

A - Lateral hearts

B - Commissural vessel

C - Sub- neural vessel

D - Lateral oesophageal vessel

Thus the correct answer is C.

[A] The first segment of the earthworm, the peristomium, contains the mouth. There is a small tongue-like lobe which is just above the mouth termed as prostomium. It is the right statement regarding earthworm.

[B] Earthworms use the prostomium to see their environment, as earthworms have no eyes, ears, nose or hands It is the wrong statement regarding earthworm.

[C] Clitellum is the ring-shaped, non- segmented glandular tissue or region in the body of annelids such as earthworm and leeches. It is the right statement regarding earthworm. It is the right statement regarding earthworm

[D] The Prostomium is actually a sensory device. It is the right statement regarding earthworm

[E] The body consists of S-shaped setae, which help in locomotion in the earthworm. It is the right statement regarding earthworm.

Thus, the correct answer is option B.

Correct Option: B

Explanation:

•  Cockroaches have malpighian tubules which extract the wastes in the form of solubles like potassium and sodium urate, carbon dioxide, and water from the haemolymph.
• The bicarbonates of sodium and potassium, water, and uric acid are formed in the Malpighian tubules. 
• This uric acid is then carried to the alimentary canal of insects.
• It is finally passed out through the anus.

Hence, The body cells in Cockroach discharge their nitrogenous waste in haemolymph mainly in the form of potassium urate.

• In Earthworm, the oesophagus is followed by the gizzard. The gizzard is a prominent oval, hard, thick-walled and highly muscular organ lying in the 8th or 8th and 9th segments. It has a thick wall of circular muscles lined by columnar cells which are further linked by the cuticle. The gizzard grinds the food into a fine state.