What two systems are responsible for controlling body activities? what structures allow them to do so

Astudent observes a star from two positions of earth in its orbit, in summer and winter, and measures the change in the position of the star. which of these can be best calculated by this method?

10. in which phase will crossing-over occur? a. mitosis b. metaphase ii c. prophase i d. meiosis ii

When a cell is in a solution that has the same concentration of water and solutes as its cytoplasm, the cell is said to be in a(n) solution. a. isotonic b. hypotonic c. hypertonic b. facilitated