Astudent is studying mitosis, in which a cell divides to form two cells. which of these shows the correct mathematical model for the process if nold shows the number of chromosomes in the parent cell and nnew shows the number of chromosomes the individual daughter cells?
a) nnew = nold
b) nnew = nold/2
c) nnew = 2 × nold
d) nnew = 4 × nold

Need the diagram below, which is not drawn to scale, shows the position of the earth, moon, and sun. what type of eclipse occurs when the earth, moon, and sun are lined up in the order shown? a. planetary eclipse b. solar eclipse c. martian eclipse d. lunar eclipse

Female luna moths (actias luna) attract males by emitting chemical signals that spread through the air. a male hundreds of meters away can detect these molecules and fly toward their source. the sensory organs responsible for this behavior are the comblike antennae visible in the photograph shown here. each filament of an antenna is equipped with thousands of receptor cells that detect the sex attractant. based on what you learned in this chapter, propose a hypothesis to account for the ability of the male moth to detect a specific molecule in the presence of many other molecules in the air. what predictions does your hypothesis make? design an experiment to test one of these predictions.

This is an active transport mechanism by which cells pump sodium and potassium ions against the concentration gradient