Class Chondrichthyes

Q. Chondrichthyes is characterized by tooth-shaped –

1. Ctenoid scale with ventral mouth
2. Ctenoid scale with dorsal mouth
3. Placoid scale with dorsal mouth
4. Placoid scale with ventral mouth

Q.

Identify the following chondrichthyes fishes.

1. 1.- Trygon , 2.- Scoliodon, 3- Pristis, 4- Carcharodon.

2. 1.- Pristis, 2.- Carcharodon, 3- Trygon , 4- Scoliodon.

3. 1.- Scoliodon, 2.- Pristis, 3- Carcharodon, 4- Trygon .

4. 1.- Carcharodon, 2.- Trygon , 3- Scoliodon, 4- Pristis.

Q.

Cartilaginous fishes do not have

1. Operculum

2. Scales

3. Gill slits

4. Pelvic fins

Q.

Ventral mouth is seen in

1. Salamandra

2. Scoliodon

3. Labeo

4. Catla

Q.

The skeleton of chondrichthyes fishes is made up of ___.

Q.

Teeth of cartilagenous fishes are modified

1. Ganoid scales

2. Cycloid scales

3. Placoid scales

4. Cosmoid scales

Q. Which of the following represents the correct combination without any exception?

1. 
   
   Characteristics - Mammary gland; hair on body; pinnae; two pairs of limbs
   Class - Mammalia
2. 
   
   Characteristics - Body covered with feathers; skin moist and glandular; fore - limbs form wings; lungs with air sacs
   Class - Aves
   
3. Characteristics - Mouth ventral; gills without operculum; skin with placoid scales; notochord replaced by the vertebral column in adults.
   Class - Chondrichthyes
4. Characteristics - Sucking and circular mouth; jaws absent, integument without scales; paired appendages
   Class - Cyclostomata

Q. What will you look for to identify the sex of the following?

1. Male shark - Claspers borne on pelvic fins
2. Female Ascaris - Sharply curved posterior end
3. Male frog - A copulatory pad on the first digit of the hind limb
4. Female cockroach - Anal cerci

Q. A marine cartilaginous fish that can produce electric current is:

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

Q. Which of the following characteristic features always holds true for the corresponding group of animals?

1. Cartilaginous - Chondrichthyes
2. Possess a mouth with an upper and a lower jaw - Chordata
3. One incompletely divided ventricle - Reptilia
4. Viviparous - Mammalia