The atomic number of an isotope is the number of protons it contains, whereas the mass number is the total mass of the nucleus, which is the combined number of protons and neutrons in the nucleus. To find the number of neutrons, you must therefore subtract the atomic number of the isotope from the mass number of the isotope.
<span>In the above example, the atomic number is 8 and the mass number is 18. This isotope is known as O18. The number of neutrons in the isotope is: Mass number - Atomic number = Number of neutrons
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Answer:
True.
Explanation:
Antigen may be defined as the chemical that has the ability to evoke the and immune response and can harm the living organisms. The specific antibody are produced against the immune response.
The antigens has evolved different mechanisms to prevent themselves from them the immune system of the host. The antigenic shift is the most common change that might occur in viruses that helps the antigen to protect itself by changing its genetic material. No anti viral drugs are available for the viruses.
Thus, the answer is true.

Cellular homeostasis involves maintaining a balance of several factors that make a cell healthy. The cell membrane is a lipid bilayer that prevents that passage of water and ions. This allows cells to maintain a higher concentration of sodium ions out the outside of the cell.
The likely results of using compulsive exercise to deal with stress are <span>fatigue and diminished performance. Since the exercise was compulsive and not based on one's own decision, the exercises done would be a burden rather than something that will relieve stress. Moreover, the compulsive exercises will only lead to the person's exhaustion and reduced productivity. </span>
The initial stages of human embryogenesis.
8-cell embryo, at 3 days.
Blastocyst with an inner cell mass and trophoblast.
Trophoblast differentiation.
Histogenesis of the three germ layers.
Artificially colored - gestational sac, yolk sac and embryo (measuring 3 mm at 5 weeks)
Embryo attached to placenta in amniotic cavity.
