In the cold, thermoreceptors in your skin detect the temperature and inform your brain, which tells the skeletal muscles to contract, causing shivering. What is the effector?

A. anaphase – sister chromatids are pulled to separate ends of the cell: During anaphase, sister chromatids separate and move to opposite poles.
B. metaphase – chromosomes line up at the center of the cell: In metaphase, chromosomes align at the metaphase plate.
C. telophase – nuclear envelope is breaking down; chromosomes are condensing: In telophase, the nuclear envelope is reforming, and chromosomes are de-condensing into chromatin. The description given fits prophase, not telophase.
D. interphase – cell is going about its daily business, at the end DNA is duplicated and starts condensing: During interphase, the cell grows and replicates DNA in preparation for mitosis.

A. isotonic; nothing: Isotonic means equal solute concentration. 0.9% NaCl is isotonic; 9.0% is much higher, so not isotonic.
B. hypotonic; crenation: A hypotonic solution has less solute than the cell. Crenation (shriveling) occurs in a hypertonic solution.
C. hypertonic; crenation: A 9.0% NaCl solution is hypertonic (more solutes than inside the cell). Water moves out of red blood cells, causing them to shrink or crenate.
D. hypertonic; lysis: Lysis (bursting) occurs in hypotonic solutions, where water enters the cell.