Option D – amphibians may use their skin for gas exchange is the characteristic feature of amphibians that differs from reptiles.
Explanation:
The amphibian skin is moist, thin and marbled and supplied by blood vessels running on its surface. The moisture present in the skin dissolves the oxygen present in its surrounding which is absorbed by the blood vessels. Special glands help the amphibians to keep the skin moist.
The very thick and tough scales present on the reptiles prevent them to absorb oxygen through their skin. Hence, they breathe and respire through their lungs.
Amphibians have three-chambered heart. They do not develop amniotic eggs. Adult amphibians although spend much time on land, they breed only in water due to the absence of amniotic sac
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Answer: different organisms have different chromosome numbers
Explanation: eukaryote cells have more than one chromosome
chromosomes are present in most cells all the time (not in erythrocytes), but cannot be visualised except during telophase of mitosis or meisosis
bacterial cells don’t have a nucleus
Three types of axonometric projection<span> are </span>isometric projection, trimetric projection. and dimetric projection.
