Why do some plants perform C4 photosynthetic pathways instead of the more common C3 pathway?

Which plains area lies in both the united states and canada? altiplano central canadian shield coastal plains great plains

Does mitochondria still meet the definition of a eukaryote why or why not?

(select all the correct choose each statement that is scientific. - the opinions of randomly selected participants in a survey prove the idea that global temperatures are not increasing on earth. - the universe's average temperature and rate of expansion support the idea that it began as one super-dense and hot mass 13.8 billion years ago. - ocean tides are caused by the uneven gravitational pulls of the moon and sun on different parts of earth. - human life is more valuable than other forms of life on earth because humans are more intelligent than other organisms.