Class Chondrichthyes

Q.

Name the reptile that has a four-chambered heart.

Q. Which among the following has electric organs?

1. Trygon
2. Torpedo
3. Pristis
4. Betta

Q.

Apply the characters of Deuterostomes and relate the characters with their nature and form a complete paragraph.

Deuterostomes:

1). Cleavage of the zygote is___i___ and intermediate.

2). During embryonic development, the other opening of the digestive system is

formed first into and the mouth is formed later, anterior to the

blastopore and blastopore into___ii___.

3). Coelom is developed as an ___iii___of archenterons.

4). Mesoderm is derived from wall of developing ___iv___.

5). Nerve cord is ___v___ in position

6). Cell fate is determined at a very ___vi___ stage

1. i - gut, ii - anus, iii - dorsal, iv - radial, v - outpouching, vi - last.

2. i - radial, ii - anus, iii - dorsal, iv - gut, v - outpouching, vi - last.

3. i - radial, ii - anus, iii - dorsal, iv - outpouching, v - gut, vi - last.

4. i - gut, ii - anus, iii - dorsal, iv - outpouching, v - radial, vi - last.

Q. The type of scales found in sharks are

1. ctenoid
2. cycloid
3. placoid
4. ganoid

Q. The skeleton of the members of the class Chondrichthyes is made up of

1. bones
2. cartilages
3. muscles
4. calcium spines

Q. Match the animal names listed under column I with the zoological names given under column II and select the correct option from the given codes.

	Column I (Common name)		Column II (Zoological name)
A.	Starfish	(i)	Sepia
B.	Jellyfish	(ii)	Asterias
C.	Devilfish	(iii)	Aurelia
D.	Cuttlefish	(iv)	Octopus
		(v)	Hippocampus

1. A-(ii), B-(iii), C-(iv), D-(i)
2. A-(iii), B-(iv), C-(i), D-(v)
3. A-(ii), B-(i), C-(iv), D-(iii)
4. A-(v), B-(i), C-(iv), D-(ii)

Q. Which one of the following groups of animals is correctly matched with its characteristic feature without any exception?

1. Reptilia : Possess 3-chambered heart with an incompletely divided ventricle
2. Chordata : Possess a mouth with an upper and a lower jaw
3. Condrichthyes : Possess cartilaginous endoskeleton
4. Mammalia : Give birth to young ones

Q. Which among the following is absent in sharks?

1. Gill cover
2. Gill slits
3. Scales
4. Pelvic fins

Q.

Cartilaginous fishes do not have

1. Operculum

2. Scales

3. Gill slits

4. Air bladder