The most important thing to note is that the vector does not get affected by the disease they are carrying. The vector can move from place to place without any hindrance and spread the disease to far away areas. This is the reason that vector borne diseases occur in large areas. Mosquitoes and flies are common vectors that carry germs and spread from people to people.
Answer: a variable is something to be changed or tested
Explanation:
The variable is the thing in an experiment that is changed
<span>From the novel "Lord of the Flies", t</span>he reason Piggy
splashes Ralph with water was that Ralph keep squirting water into Piggy's
face, thereby wetting Piggy's glasses. Piggy's retaliation shows that he
is becoming more protective of his glasses, which symbolizes his feelings
towards maintaining civility on the island. At this point in the novel, Piggy
realizes the importance of remaining civil and defending himself against the
impending barbarism.
<h2>Evolution of Earth</h2>
Explanation:
The events of earth history from oldest to new are as follows:
- Earliest evidence of life on Earth.
- Production of oxygen by photosynthetic organisms.
- Origin of Eukaryotic cell.
- appearance of first tetrapods on land.
Scientists assume that the Earth evolved about 4.6 billions years ago. However, the first evidence of life dates back to 3.7 billion years ago. It is assumed that the conditions of primitive Earth were such that it could not support life. However the inorganic compounds spontaneously reacted and gave rise to biological molecules such as amino acids, proteins lipids etc.In this way the first cells appeared as prokaryotes, photosynthetic prokaryotes began to produce oxygen and gradually new forms of life arose.
An important event in the history of Earth is cambrian explosion during which several forms of life arose and diversified to occupy various strata of Earth.
1-centrosome
2-spindle fibers
9-chromosome
10-nucleus(nuclear membrane)