Crossing over is termed as a process by which genetic materials are exchanged by non-sister chromatids during meiosis.
Crossing over results in the new combination of information in genetic for, the cell for a specific trait.
It ensures that organisms are identical from one generation to another. Genetic recombination allows variations in genetic materials which are passed through generations.
The answer is; A
Nebulae are clouds of dust and gas in space. When local areas in nebulae start to collapse under their own weight and fusion begins, a star is born. This, therefore, means that a star is denser than nebulae because it requires that atoms fuse for it to form. Fusion creates heavier atoms from light atoms.
Answer:
Birds and bats have homologous limbs because they are both ultimately derived from terrestrial tetrapods, but their flight mechanisms are only analogous, so their wings are examples of functional convergence.