A jawless fish, which lays eggs in freshwater and whose ammocoetes larvae after metamorphosis return to the ocean is?
1. Eptratretus
2. Myxine
3. Neomyxine
4. Petromyzon
Which of the following represents the correct combination without any exception?
Characteristic | Class |
(a) Mammary gland; hair on body; pinnae; two pairs of limbs | Mammalia |
(b) Mouth ventral; gills without operculum; skin with placoid scales; persistent notochord | Chondrichthyes |
(c) Sucking and circular mouth; jaws absent; integument without scales; paired appendages | Cyclostomata |
(d) Body covered with feathers; skin moist and glandular; lungs with air sacs; forelimbs from wings | Aves |
1. | a | 2. | b |
3. | c | 4. | d |
A marine cartilaginous fish that can produce electric current is:
1. Pristis
2. Torpedo
3. Trygon
4. Scoliodon
1. | Gill slits are ventrally placed |
2. | Head and trunk are widened considerably |
3. | Distinct demarcation between body and tail |
4. | Their pectorals fins are distinctly marked off from cylindrical bodies |
Which one of the following pairs of animals is similar to each other pertaining to the feature stated against them?
1. | Garden lizard and Crocodile - Three-chambered heart |
2. | Ascaris and Ancylostoma - Metameric segmentation |
3. | Sea horse and Flying fish - Cold-blooded (poikilothermal) |
4. | Pteropus and Ornithorhyncus - Viviparity |
1. | Male frog – a copulatory pad on the first digit of the hind limb |
2. | Female cockroach – anal cerci |
3. | Male shark – claspers borne on pelvic fins |
4. | Female Ascaris – sharply curved posterior end |
1. | Chordata – possess a mouth provided with an upper and a lower jaw |
2. | Chondrichthyes – possess cartilaginous endoskeleton |
3. | Mammalia – give birth to young ones |
4. | Reptilia – possesses 3-incomplete heart with one incompletely divided ventricle. |