If halley's comet has an orbital period of 75 years what is the length of its semi major axis

This is one form of rna that transports a specific amino acid to a ribosome during protein synthesis.

Asample of digestive juice was removed from the stomach of a pig. the juice was placed in a test tube along with some grains of wheat. a second test tube was set up containing an equal number of wheat grains, with distilled water rather than digestive juice. the test tubes were kept for 8 hours at 40 degrees c. after 8 hours, the grains inside the digestive juice had broken into tiny particles. the grains of wheat, in the water, were wet but otherwise unchanged. what is the control group?

Discuss the similarities and differences between whale flippers and tail flukes(*back fins, not the fish) and fish fins, using the scientific terms "homologous structures" and "analogous structures" in the discussion (5-7 sentences)