HIV directly attacks CD4 helper lymphocytes directly. (D)
Answer:
Here are the correct order of events that show evolution of the universe:
- Inflation
- Separation of last two fundamental forces
- Formation of subatomic particles
- Nucleosynthesis
- Formation of first stars
Explanation:
According to big bang theory, there were series of events carried on that lead to the formation of stars in the universe.
- Inflation was the time when universe began to expand at extremely fast pace.The dimensions of that old universe during the fraction of a second expanded by a factor of at-least 10^26 to 10 cm. Elementary particles like quark began to expand into the thin layer of universe.
- A strong nuclear force separated from its other two forces and the interactions between already created particles lead to the formation of more particles like Higgs bosons, W and Z etc.
- When the universe began to cool down below 10 quadrillion degrees, neutrinos, electrons and quarks began to form. Antiquarks and quarks annihilated with each other in a process called baryogenesis, this lead to the formation of matter.
- When the universe began to cool down below a billion degrees, the atomic nuclei begin to form when neutrons and protons combined by fusion reactions. The initially created nuclei were of simplest elements like helium, hydrogen and lithium.
- The period between the formation of first stars and atoms is called as dark age because there were no stars at that time. The formation of stars and galaxies was made 300 - 500 million years later. When the universe was kept expanding, gas pockets and gases became more and more dense. The small gas particles were collapsed under own gravity and became so hot that fusion reactions were triggered in them. Fusion between hydrogen atoms was the reaction which lead to the formation of most primitive stars.
Solar thermal energy and solar electric energy because people like to conserve energy and help the earth so they use solar thermal energy. But people who are not enough nice to the earth they would use solar electric energy
Answer:
In the given case, the flowers A and B are temporally reproductively isolated from each other.
Explanation:
Reproductive isolation takes place when populations cannot mate efficiently with each other. As a consequence, slight genetic differences originate within the populations. With time, the genetic differences gathered in the isolated populations results in the formation of various kinds of different species. In the given case, even though both the flowers A and B are the similar species, the two different flowers bloom at distinct times, resulting in a time-imposed or temporal barrier to reproduction.
<span>After
digestion, an amino acid not absorbed by the body and not used to build
proteins will first be subjected to removal from its amino group. If they are
not used for protein synthesis, amino acids becomes part of the metabolism
process. The body has the capability to create a subset of amino acids, also
known as non-essential amino acids because we don’t have requirement for them
in our diet. </span>
