The stronger survived and the weaker passed on... Those with a weaker immune system had trouble with sickness and usually ended up passing on but those with strong immune systems were stronger and healthier and lived.
<u>Answer</u>: Ionic bond
<u>Explanation</u>:
- An ionic bond is a type of a chemical bond formed by the complete transfer of electrons from one atom to another atom i.e one of the atoms loses its electrons and the other gains it. This results in the formation of 2 oppositely charged ions.
- In sodium chloride, sodium loses one electron from its outermost shell (valence shell) whereas chloride gains it. Due to this sodium gains, a net positive charge and chloride gain a net negative charge.
- So, due to the complete transfer of electrons that takes place from sodium to chloride, the compound generated (Sodium chloride) has an ionic bond.
Answer:
<em>The correct option is C) OH</em>
Explanation:
In the field of chemistry, radicals can be described as atoms, molecules or ions which have at least one unpaired electron.
The formation of a radical occurs when a single covalent bond breaks so that each of the atoms that had been involved in the formation of the covalent bond can have an unpaired electron. Examples of radicals include OH, NH4+ etc.
Other option, like option B, is not true because a molecule of water does not have any unpaired electrons in its valence shell.
Answer:
The correct answer is D. proliferation and differentiation.
Explanation:
Primary immune response occurs due to the first exposure of an antigen to the immune system. The primary immune response is generally delayed by many days because it takes time for B and T cells to become cloned and to proliferate and differentiate.
Then after several days of proliferation and differentiation of activated T and B cells, T cells become effector T cells and B cell becomes plasma cells which then eliminates the antigen. Memory B and T cells are also produced during this process which helps in generating a quick immune response during the second and subsequent exposure of that antigen.
So the correct answer is D. proliferation and differentiation.
No!!
Size of a cell doesn't depend on size of an
organisms, Their number maybe different 'cause of size but their cell
would remain same.
Hope this helps!
