Question 26

certain types of atoms break down at a known rate. scientists can measure the amounts of the broken down products present in a sample to calculate its age. what is this technique called?

natural selection

the fossil record

speciation

radiometric dating
2 points
question 27

during which era did plants first appear on land?

cenozoic

mesozoic

paleozoic

precambrian
2 points
question 28

how were multicellular organisms developed on early earth?

eukaryotes began grouping together to develop multicellular organisms

cyanobacteria released oxygen molecules into the air creating new multicellular organisms

prokaryotes combined to form new multicellular organisms

prokaryotes combined with cyanobacteria to develop multicellular organisms