Question

Which of the following traits is not characteristic of amphibians?
A.Usually requires water for reproduction
B.Amniote egg
C.Skin used as supplementary respiratory organ
D.Thin, scaleless skin

Answer 1

Hint: Amphibians require water for effective reproduction. Amphibian larvae are often aquatic and they go through a complex metamorphosis process as they grow to adults

Complete step by step answer:
- The life cycle of an amphibian reflects its evolutionary history of bridging land and water. Most amphibians lay their eggs in freshwater, a few species tolerate brackish (saline) water and some species lay their eggs on land. These eggs aren’t amniotic in nature
-Amniotic eggs are those that contain albumin. It provides the embryo with water and protein; the egg yolk supplies the embryo with energy and also provides a medium of excretion. The chorion, amnion, and allantois are key membranes that are found only in amniotic eggs. The chorion facilitates gas exchange between the embryo and the external environment of the egg
-Amphibians have moist skin. They do not have scales, feathers, or hair. The moist skin provides a mode of respiration (diffusion) in amphibians

Hence option B is correct.

Note:
-Several amphibians utilize cutaneous respiration. These amphibians have extensive folds on their skin to increase the rate of respiration. For example, the hellbender salamander and the Lake Titicaca water frog. Cutaneous respiration in hellbenders accounts for more than 90 percent of oxygen uptake and carbon dioxide excretion compared to other modes of respiration.
-The eggs that are laid near or in water bodies float for a few days till tadpoles emerge from it. The amount of sperms released by the males is very high compared to the number of eggs required to fertilize. This is done to compensate for the loss of sperms as fertilization occurs in water bodies.