Question

Which one of the following groups of animals is correctly matched with its one characteristic feature without even a single exception?

• A. Mammalia: Give birth to young ones
• B. Reptilia: Possess 3-chambered heart with one incompletely divided ventricle
• C. Chordata: Possess a mouth provided with an upper and a lower jaw
• D. Chondrichthyes: Possess cartilaginous endoskeleton

Answer 1

The correct option is D

Chondrichthyes: Possess cartilaginous endoskeleton

The correct option is D.
Explanation for the correct option:
Option D:

1. The class of cartilaginous fishes known as Chondrichthyes includes these fishes, which have skeletons predominantly made of cartilage.
2. They can be compared to Osteichthyes, also known as bony fishes, whose skeletons are primarily made of bone tissue.
3. The term "endoskeleton" refers to the body's cartilaginous and bony skeleton, excluding the dermal-derived portion of the skeleton.
4. Fish belonging to the phylum Chondrichthyes include skates, sharks, and rays.

Explanations for the incorrect options:
Option A:

1. Mammary glands, which in females generate milk for feeding their young, a neocortex, fur or hair, and three middle ear bones are characteristics of the class of vertebrate creatures known as mammals.
2. There are only five species of monotremes in the world, including the platypus and the echidna.
3. These mammals don't give birth to live young; instead, they lay eggs.

Option B:

1. The animals in the class Reptilia are what are popularly referred to as reptiles.
2. They are members of the animal kingdom's phylum Chordata and are cold-blooded creatures.
3. A three-chambered heart with two atria and one ventricle is found in reptiles.
4. The right atrium receives deoxygenated blood from different areas of the body, while the left atrium receives oxygenated blood from the lungs and/or gills.
5. The crocodile is an anomaly, having a heart with four chambers.

Option C:

1. An animal belonging to the phylum Chordata is a chordate.
2. The huge animal phylum known as Chordata contains all vertebrates as well as sea squirts and lancelets.
3. They can be identified by having a notochord at some point in their development.
4. Jaws are not developed in early chordates like Agnatha (cyclostomes).
5. The agnathans lack paired fins and jaws.
6. They lack jaws, instead using a cyclotomic (round) toothed mouth to drill into a fish's side and drain the blood of their prey.

Final answer: Chondrichthyes groups of animals are correctly matched with its one characteristic feature without even a single exception.