Which mammals tolerate exceptionally high levels of carbon dioxide?
Moles are adapted to survive in low-oxygen environments such as underground burrows. They tolerate higher levels of carbon dioxide than other mammals because their blood cells contain a special form of hemoglobin.
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How do baby birds get oxygen inside their eggs?
They have a large oxygen supply from the start
Oxygen is created during protein reduction
Oxygen comes in through pores in the shell
They don't need oxygen at all