Question

Select the correct statements with reference to chordates.
A. Presence of a mid-dorsal, solid and double nerve cord.
B. Presence of closed circulatory system.
C. Presence of paired pharyngeal gill slits.
D. Presence of dorsal heart
E. Triploblastic pseudocoelomate animals.
Choose the correct answer from the options given below:

• A. B and C only
• B. B, D and E only
• C. C, D and E only
• D. A, C and D only

Answer 1

The Correct Option is A

Explanation of the correct statements:

B. Presence of a closed circulatory system - Many chordates, including vertebrates, have a closed circulatory system, where blood is enclosed within vessels, allowing for efficient distribution of oxygen, nutrients, and waste products.
C. Presence of paired pharyngeal gill slits - One of the defining characteristics of chordates is the presence of pharyngeal gill slits in their embryonic stages. In some chordates, these gill slits are also present in the adult stage and may be used for respiration or other functions.

The other statements are incorrect: 

A. Presence of a mid-dorsal, solid, and double nerve cord - Chordates do have a nerve cord, but it is not always mid-dorsal, solid, or double in all chordate groups. In vertebrates, the nerve cord is typically dorsal, but the characteristics mentioned in the statement do not apply universally.
D. Presence of a dorsal heart - Chordates, particularly vertebrates, typically have a ventral (located on the underside) heart, not a dorsal heart.
E. Triploblastic pseudocoelomate animals - Chordates are not pseudocoelomate. Chordates belong to the deuterostome group, and the most well-known and advanced members, the vertebrates, are not pseudocoelomate; they have a true coelom.

So, the correct option is (A): B and C only