Phylum Chordata

Choose the correct statement.

1.	All mammals are viviparous
2.	All cyclostomes do not possess jaws and paired fins
3.	All reptiles have a three-chambered heart
4.	All Pisces have gills covered by an operculum

All vertebrates are chordates but all chordates are not vertebrates, why?

1.	Notochord is replaced by a vertebral column in the adults of some chordates.
2.	The ventral hollow nerve cord remains throughout life in some chordates.
3.	All chordates possess a vertebral column.
4.	All chordates possess notochords throughout their lives.

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R)

Assertion (A):	All vertebrates are chordates but all chordates are not vertebrates.
Reason (R):	Notochord is replaced by vertebral column in the adult vertebrates.

In the light of the above statements, choose the most appropriate answer from the options given below:

1.	(A) is False but (R) is True.
2.	Both (A) and (R) are True and (R) correctly explains (A).
3.	Both (A) and (R) are True and (R) does not correctly explain (A).
4.	(A) is True but (R) is False.

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:

1.	C, D and E only	2.	A, C and D only
3.	B and C only	4.	B, D and E only

Match List-I with List-II:

	List-I		List-II
A.	Pterophyllum	I.	Hag fish
B.	Myxine	II.	Saw fish
C.	Pristis	III.	Angel fish
D.	Exocoetus	IV.	Flying fish

Choose the correct answer from the options given below:

1.	A-III, B-I, C-II, D-IV
2.	A-IV, B-I, C-II, D-III
3.	A-III, B-II, C-I, D-IV
4.	A-II, B-I, C-III, D-IV

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:

1.	A, B & D only
2.	B, D & E only
3.	B, C & D only
4.	A & C only

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A):	All vertebrates are chordates but all chordates are not vertebrate.
Reason (R):	The members of subphylum vertebrata possess notochord during the embryonic period, the notochord is replaced by a cartilaginous or bony vertebral column in adults.

In the light of the above statements, choose the correct answer from the options given below :

1.	(A) is True but (R) is False.
2.	(A) is False but (R) is True.
3.	Both (A) and (R) are True and (R) is the correct explanation of (A).
4.	Both (A) and (R) are True but (R) is not the correct explanation of (A)