Question

The following are the statements about non- chordates:
A. Pharynx is perforated by gill slits.
B. Notochord is absent.
C. Central nervous system is dorsal. 
D. Heart is dorsal if present.
E. Post anal tail is absent.
Choose the most appropriate answer from the options given below:

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

Answer 1

The Correct Option is C

The question requires identifying the non-chordate characteristics from the given statements. Let's analyze each one:

A. Pharynx is perforated by gill slits: This is a feature commonly found in chordates rather than non-chordates.

B. Notochord is absent: This is true for non-chordates since they lack a notochord.

C. Central nervous system is dorsal: This is characteristic of chordates, not non-chordates.

D. Heart is dorsal if present: Non-chordates usually have a ventral heart if they have one, making 'dorsal heart' unlikely for non-chordates.

E. Post anal tail is absent: Most non-chordates do not have a post-anal tail.

Based on the analysis, the correct statements matching non-chordate characteristics are B (Notochord is absent) and E (Post anal tail is absent). Hence, the correct answer is: B. D & E only

Answer 2

Evaluating Statements about Non-Chordates:

• Statement A: Incorrect – Pharyngeal gill slits are found in chordates, not all non-chordates.
• Statement B: Correct – Non-chordates lack a notochord.
• Statement C: Incorrect – In non-chordates, the central nervous system is ventral, not dorsal.
• Statement D: Correct – In many non-chordates, the heart (if present) is dorsal.
• Statement E: Correct – Many non-chordates lack a post-anal tail.

Thus, the correct answer is (3) B, D & E only.