If an isotope's half life is 2 months, and it starts with 240 grams. How many half life's does it take to only have 15 grams left? A. 2
B. 4
C. 6

Will mark you as ! keiko’s teacher was discussing the theory of endosymbiosis. she asked keiko to mark the organelles in the diagram that most closely resembled prokaryotes. which organelles should keiko mark? * the first image is the question and the second image is some information to you answer the !

Is there any solid scientific evidence that humans have been cloned?

What's wrong with this ecological pyramid? (multiple choice)1. secondary consumers should be at the bottom of the pyramid2. the sun has an arrow leading to decomposers 3. primary consumers should come after the sun4. energy retained should increase from the bottom to the top5. the sun should be at the bottom of the pyramid