Blood that flows to the lungs contains more carbon dioxide than oxygen is called what?

Asap i will reward you brainliest for best which sentence about protists is accurate? all protists are unicellular and microscopic in nature. they have organelles, so protists are eukaryotic in nature. all protists make their own energy through photosynthesis.

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

Match the reproductive structures based on their function and the system to which they belong. egg ovary sperm vas deferens vagina fallopian tube testis urethra