<u>Answer:</u>
Mitochondria, the organelles involved in cellular respiration, can also generate chemicals called reactive oxygen species (ROSs). ROSs can damage mitochondria. Damaged mitochondria generate more ROSs than healthy mitochondria. This is an example of a positive feedback mechanism
The reactive oxygen species that are given out by the mitochondria during cellular respiration are the major cause of aging. Though this has a lot of negative effects but this also has a small amount of positive effects such as the start of angiogenesis or cell proliferation.
There cannot be more carnivores than herbivores because the carnivores eat the herbivores. If there wasn't enough herbivores to eat, then the carnivores would eventually become extinct.
<span>(According to Reference)
Whereas an onion epidermal cell has a cell wall, a human cheek cell does not. Instead, a semi-permeable membrane surrounds the cytoplasm of the cheek cell. While there are chloroplasts present in onion cells, they are absent in cheek cells. </span>