Molecular Biology
This field of study deals with everything related to macromolecules, thus, what you will need for molecular biology would be something you could get proteins and nucleic acids from. Among the choices, the DNA of a pig and a calf would be the most helpful.
Comparative Anatomy
Comparative anatomy is a field of study that focuses on any similarities or differences between the anatomy or structure of different animals or species in general. Among the options, having the limb structure of a pig and a calf would allow you to practice the field since you have a structure to compare.
Developmental Biology
In this field, your concern would be how species grow and develop. For you to properly observe the growth and development, you must have the embryo of a pig and a calf. Therefore, among the options, this is the correct piece of evidence for this field.
IN SUMMARY:
Molecular Biology - Both DNA of a pig and a calf
Comparative Anatomy - Both limb structure of a pig and a calf
Developmental Biology - Embryo of a pig and a calf
Explanation:
It sends message directly to muscles and glands
When cells reach their size limitations one of two things will happen: they will either stop growing and split into two separate cells. Cell division can be both good and bad.
All of these components are reservoirs of carbon. The cycle is usually discussed as four main reservoirs of carbon interconnected by pathways of exchange. The reservoirs are the atmosphere, terrestrial biosphere (usually includes freshwater systems), oceans, and sediments (includes fossil fuels).