Answer:
The macromolecule is nucleic acids (more importantly the nucleotides)
Explanation:
Nucleotides belong to the DNA/ nucleic acid part of macromolecules.
I think the correct answer would be A. The yolk sac becomes the placenta. It is membranous sac that is attached to the embryo. It provides all the nutrition and the blood cells needed by the embryo. It is also called the umbilical vesicle.
Answer:
The transfer of energy through empty space is called convection.
Explanation:
One of the fundamental laws of the universe is the conservation of energy. Energy can't be created and it can't be destroyed. Convection can be the process by which heat is transferred . Temperature is known as the basic principle of heat transfer. The amount that how much of thermal energy can be available is determined by the temperature, and the heat flow represents movement of thermal energy.