Answer:
I) Sexual reproduction
II) Mutation
Explanation:
Variations refer to the difference observed within organisms of the same species. Variation are introduced into a population by:
- new genetic combinations that occur during sexual reproduction (i.e during meiosis)
- mutations, spontaneous changes that occur in genes and chromosomes.
Answer:
a. Endocytosis involves the opsonization of a receptor and its ligand in clathrin-coated vesicles, along with the inward budding of the plasma membrane. In exocytosis, waste material is enveloped in a membrane that fuses with the interior of the plasma membrane via attachment proteins.
Explanation:
Endocytosis: entails the external binding of a ligand to its receptor which is located on the external side of the plasma membrane. The membrane buds inwardly for internalization to occur.
Exocytosis: material that has been processed inside the cell is transported by vesicles which fuse to the internal side of the plasma membrane and ultimately transported to the outside of the cell.
Well they can begin as cosmic rays colliding with water molecules to create clouds. Hope this helps :)