Answer:
B) All DNA molecules will migrate up the gel toward the positive electrode.
Explanation:
Because the DNA has a negative charge - regardless the size-, all DNA molecules will migrate towards the positive electrode, at the top of the gel. This is due to the Coulomb's physic law "force of the interaction between the charges is attractive if the charges have opposite signs".
Instead of migrate down the gel , the DNA will do migrate up the gel (opposite direction).
Crossing-over is the exchange of genetic material between homologous chromosomes. It results in new combinations of genes on each chromosome. When cells divide during meiosis, homologous chromosomes are randomly distributed to daughter cells, and different chromosomes segregate independently of each other.
What following ? actually the cell will gain more water by diffusion and will let more sodium chloride ions in because they will move from high concentration to low concentration
homologous chromosomes ... sister chromatids
