The correct answer is random fertilization.
Together with crossing over and independent assortment, random fertilization represents the way by which sexually reproduction contributes to genetic variation. <span>Random fertilization refers to the random event of fertilization when there is no way in knowing which sperm will fertilise which egg (64 trillion possible combinations of genes that can occur during fertilization). Any sperm cell from the male can fuse with any egg cell from the female.</span>
<span>The study of the interactions of genes with the environment is called Epigenetic, is how genes are expressed in relation to environmental factors and how diseases and other conditions develop. It is the study of the impact of environment and lifestyle on the behavior of genes and the way it responds to external factors.</span>
We can do brain scans and things that help us diagnose sickness
<em>The function of skeletal muscles is to control the movement of internal organs. The skeletal muscle pulls the tendons attached to the bones.</em>
Meiosis has two rounds of genetic separation and cellular division while mitosis only has one of each. In meiosis homologous chromosomes separate leading to daughter cells that are not genetically identical. In mitosis the daughter cells are identical to the parent as well as to each other.