Keith is observing a slide of an amoeba under a compound microscope. He places a stained fine particle of yeast near the amoeba.
He observes that the amoeba is engulfing this particle by extending its pseudopodia. Which process is the amoeba exhibiting? pinocytosis
exocytosis
phagocytosis
receptor mediated endocytosis
Today, the atmosphere holds about 21 per cent oxygen. ... When the first simple organisms appeared in the oceans more than 3.5 billion years ago, the atmosphere was mostly nitrogen, hydrogen, water vapor, and carbon dioxide
