From the earliest moments of life, the interaction of heredity and the environment works to shape who children are and who they will become.
The complex interaction of nature and nurture does not just occur at certain moments or at certain periods of time; it is persistent and lifelong.
The reason why we were unable to read the lab manual through the tubes containing isotonic and hypertonic solution is because the cells in those solutions remained intact, causing the solutions to be opaque, in the tonicity of red blood cells activity. The reason why we can't read the lab manual is because the cells in the solutions remained intact.