Answer:
In biology, evolution is the change in the characteristics of a species over several generations and relies on the process of natural selection. The theory of evolution is based on the idea that all species? are related and gradually change over time.
From what i know, the feet of an animal should always be on the table. This is due to the fact that aside from health reason's, the animal usually feels more comfortable not on it's back.
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:
because they have thicker walls
Explanation:
blood is punped our of the heart very fast which means it would need a blood vessel witch thick walls to withstand the pressure. thin walls would cause the blood vessle damage and may evwn break as it wouldn't be able to withstans the pressure.