Fill in the blanks. David is a research scientist who is giving a lecture to a class of students on how life began on Earth. Help him complete the sentences.
Scientists have found (shells, stromatolites, rocks) containing fossilized cyanobacteria (blue-green algae). They show that life has been present on the Earth from early ages. Oparin and Haldane were two scientists who hypothesized that life needed reducing environments initially to appear. The ocean in the early ages was (anoxic, toxic, pyrexic) and acidic.

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? question 8 options: the cold balloon expands and rises. the warm balloon shrinks and sinks. the balloons rise at the same rate. both balloons are the same size. the ballons both rise. the cold ballon is larger than the warm balloon. the warm balloon expands and rises. the cold balloon shrinks and sinks.

Amap's orientation is typically determined by an

What do we call the process when two dominant alleles are expressed and do not blend? a. incomplete dominance b. codominance c. multiple alleles