4. A student observing a sample of cheek cells noticed that all of the cells 20 points were identical. Which statement below explains why these cells are
identical? *
They all come from the same location in the body.
All cells come from other cells through division.
They do not have a cell wall.
They have a chloroplast.
Explain the three main components of cell theory.*
20 points
Your answer

)benzene and toluene form nearly ideal solutions. consider an equimolar solution of benzene and toluene. at 20 °c the vapour pressures of pure benzene and toluene are 9.9 kpa and 2.9 kpa, respectively. the solution is boiled by reducing the external pressure below the vapour pressure. calculate (i) the pressure when boiling begins, (ii) the composition of each component in the vapour, and (iii) the vapour pressure when only a few drops of liquid remain. assume that the rate of vaporization is low enough for the temperature to remain constant at 20 °c.

Consider a culture medium on which only gram-positive organisms such as staphylococcus aureus colonies can grow due to an elevated nacl level. a yellow halo surrounds the growth, indicating the bacterium fermented a sugar in the medium, decreasing the ph as a result and changing the color of a ph indicator chemical. this type of medium would be referred to as a differential and enrichment culture.

Amethod of separation that employs a system with two phases of matter, a mobile phase and a stationary phase, is called