Several studies of adolescents<span>, including one </span>with more<span> than 3,000 high school students, found that inadequate </span>sleep<span> is associated </span>with<span> higher levels of depressed mood, anxiety, behavior </span>problems,<span>alcohol use, and attempted suicide. </span>
Answer:
The correct option is : b. centrosome
Explanation:
Centrosome is a cell organelle, which acts as the microbule organizing center and also regulates the cell cycle progression in an eukaryotic cell.
During the prophase stage of the cell cycle, the centrosomes are associated with the membrane of the nucleus. The nuclear membrane ruptures during the mitosis and the interaction of the centrosome nucleated microtubules with the chromosomes leads to the formation of the mitotic spindle.
<u>Therefore, mitotic spindles arise from the centrosome.</u>
<span>This averages about 75 percent. This type of cocaine is a free base cocaine and is smoked. The high that it gives to the smokers is short but intense. It is also known as the most addictive form of cocaine.</span>
Answer:
Prokaryotes are smaller and less developed compared to eukaryotes. Some of them inhabit very primitive environments that resemble earth’s early stages. Endosymbiotic theory states that eukaryotes arose by the endosymbiosis of prokaryotes.
Explanation
By endosymbiont theory, eukaryotic cells arise from prokaryotic cells. Here, the theory shows that eukaryotic ancestors lived in close association with prokaryotes, wherein in some cases, prokaryotes have been engulfed and might have lived inside eukaryotes.
Upon being engulfed by a host cell as undigested prey, these prokaryotes could have been internal parasites of the eukaryotes. But, later on, their relationship becomes mutualistic and these prokaryotes become incorporated as organelles, such as in the case of chloroplasts and mitochondria, which were previously separate prokaryotes
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