HIV is a retrovirus. Which sequence does it use as part of its reproductive cycle?
A. RNA DNA → RNA protein
B. protein
- DNA - RNA → DNA
C. DNA - RNA DNA protein
D. RNA - protein - RNA - DNA

25) a student takes four samples of a white crystalline solid and places each in a well plate. on top of each sample, she carefully places 20 drops of clear mystery liquids a, b, c and d. her results for each well are: liquid a: the solid dissolves quickly. liquid b: the solid appears unchanged. liquid c: a brownish colored liquid is produced. liquid d: fizzing occurs and the well becomes warmer. in which well does a physical change occur?

Which set of characteristics best describes sedimentary rock? a) largest type of rock, made of organic matter, hardest type of rock b) often contains layers, forms near sources of water, contains fossils c) least abundant type of rock, made of other rocks, made mostly of minerals d) most abundant type in earth's crust, made of magma/lava, contains no fossils

Which chemical bond most likely stores the most energy? o a. double carbon-carbon bond o b. single carbon-carbon bond o c. hydrogen-oxygen bond o d. sodium-chlorine bond