Artificial selection simply means crossing two species that posses desired traits . These desired traits are brought into the offspring through artificial selection.
In artificial selection there is no use of test tube babies or robots as nothing like genetic engineering processes are involved here.
Only the species of plants and animals that possesses desired characteristics are segregated and kept together thereby restricting natural selection. Rest all activities/processes is to be done by the selected species themselves . In order to produce a desired species of plant or animals the selected species have to mate and this they have to do by themselves.
Thus, Artificial selection does not involve the use of robots and "test tube babies."
Spongy bone has trabecular which serve as reinforcing plates against a force. The loss of spongy bones causes weakening of the internal support that the compact bone requires and the entire bone breaks.
