Question

Which of the following are anamniotes?
(a)Chondrichthyes, Osteichthyes and amphibia.
(b)Reptilia, Aves, and Amphibia.
(c)Amphibia, Aves, and Mammals.
(d)Reptilia, Mammals, and Aves.

Answer 1

Hint: The group of animals which lacks the amnion layer and they lay eggs in water. They undergo external fertilization.

Complete answer:
These are the groups of animals that need water to lay eggs. They need it to exchange gases and waste within the water surrounding due to the absence of the amnion layer. The group includes Chondrichthyes, Osteichthyes, and Amphibia.’

Additional Information: The groups included in Anamniotes are:
-Jawless fishes like lampreys, hagfish, etc.
-Cartilaginous fishes like sharks, rays, skates, etc.
-Bony fishes include ray-finned fishes and lobe-finned fishes.
-Amphibians like frogs, salamanders, etc.
- A single inner membrane is observed in the case of fishes and amphibian eggs, the embryonic membrane.
The group of Anamniotes can be characterized by the following:
-Absence of an amnion that encloses the embryo.
-Presence of nucleated red blood cells.
- They have permeable skin which allows for the diffusion of water and gases through their skin.
-These are present at some period of life of gills.

So the correct answer is ’Chondrichthyes, Osteichthyes, and Amphibia.’

Note: They are of two types of vertebrate groups. They are Amniotes and Anamniotes.

Amniotes	Anamniotes
They lay eggs on land and they retain the fertilized egg within their mother.They are higher vertebrates.They include Reptiles, Aves, and Mammals. Example: crocodile, human beings, etc.	They lay their eggs in water.They are lower vertebrates.They include fishes(Chondrichthyes and Osteichthyes) and Amphibians. Examples: frog, salmon, etc.