The 5' end has free phosphate group while the 3' end has free OH group.
Explanation:
Each DNA strand has two ends that differ from each other with respect to the functional group. The nucleotide present at the 5' end of a DNA strand has a free phosphate group. This phosphate group of other nucleotides of the DNA strand is bonded in phosphodiester bonds. Likewise, the 3' end of a DNA has a free OH group. This makes the two ends of a DNA strand quite different from each other. A DNA new nucleotide can be added to the 3' end due to the presence of a free OH group.
Embryonic development involves process of formation and development of an embryo. In humans, during the early stages, 10 weeks of embryonic development, all the major body organs are formed.