Hundreds of years ago, it was believed by many that our solar system was Geocentric. This means that Earth is at the center of the solar system, with the Sun and other planets orbit around it. Today, the solar system is now thought to be Heliocentric. What does this mean?

In which of the following ways is the function of the surface of a microsphere similar to the function of an actual cell membrane? a.both make it possible for the conditions in the interior to be different from the conditions outside. b.both provide a barrier that keeps water from flowing across it so the interior remains dry. c.both separate the rna that forms in the interior from any rna that might form in the environment. d.both can actively move molecules into the interior or out into the surrounding environment.

What links the two strands in a dna helix together in the middle? a. phosphate groups b. sugar rings bonded together c. proteins d. bases with hydrogen bonds

Draw the structure of dna nucleotide with adenine as nitrogenous base