Answer:

point mutation, change within a gene in which one base pair in the DNA sequence is altered. Point mutations are frequently the result of mistakes made during DNA replication, although modification of DNA, such as through exposure to X-rays or to ultraviolet radiation, also can induce point mutations
I think the best medium is agar. It is a jelly-like substance that is obtained from algae, and is used to culture small organisms such as microorganisms and bacteria.
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Answer:
With microscope.
Explanation:
Every cell has a selective permeable membrane in which smaller molecules can pass whereas bigger molecules stays outside the cell which can be seen in the cell with the use of microscope because it only occurs inside the cell. The movement of ions or molecules in the cell through a semi permeable membrane is called Osmosis. The movement of ions or molecules sometime needs energy we called it active transport and sometimes it moves without the use of energy is known as passive transport.
Answer:
Vitamins A and D are added to margarine during production so it will have a similar vitamin level to butter. Nutrients may also be added to foods to fortify or enrich them even if the vitamins and minerals added are not normally contained in that food.Margarine makes an important nutritional contribution to the diet by being a source of one or more essential fat-soluble vitamins such as vitamins A and/or D and by being low in saturated fat.