D) Fossils could not be found in that layer of rock.
The answer is pronuclei. A pronuclei is the state of the
nucleus of either the sperm or the ovum after the sperm has entered the ovum
but the two nuclei have not yet fused. When the sperm enters the ovum, the membrane
of the sperm pronuclei dissolves hence leaving no barrier for the two genetic
materials to combine.
Both plant and animal development is seeded in the perspective that a cell divides itself to form a tissue and tissues grouped will become an organ and the organism itself. The cell hierarchial model is followed in the development in both of these diverse however seemingly similar organisms.
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.
