Mitochrondria of the eukaryotic cells.
<span>As many researchers hypothesize that the old single-celled organism or the origin of the complex-celled organisms came from the endosymbiosis of the mitochrondrion organism and the prokaryotic cell. It has been said that mitochondria was an independent organism which then to have been evovled itself after planting itself inside a prokaryotic cell which aided cellular respiration and production of ATP (Adenosine Triphosphate). This then aided the prokaryotic cell to be more sophisticated and caused another change from having without a true nucleus to a eukaryotic cell with a nucleus and embedded DNA. <span>
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Answer: Maintaining a good level of physical fitness is something that we should all aspire to do. But it can be difficult to determine what fitness entails. According to the United States Department of Health and Human Services, physical fitness is defined as “a set of attributes that people have or achieve that relates to the ability to perform physical activity.”This description goes beyond being able to run fast or lift heavy weights. Despite being important, these attributes only address single areas of fitness. This article provides details of the five main components of physical fitness.
Explanation: hope this help
Answer:
B) Nitrogen-fixing bacteria and lightning
Explanation:
Nitrogen cycle is the natural process in which atmospheric nitrogen is converted into nitrite and nitrate with the help of bacteria.
Nitrogen cycle is directly dependent on nitrogen-fixing bacteria and lightning.
As bacteria are responsible for most of the chemical conversion in the nitrogen cycle such as nitrogen fixation (first step) is done by soil bacteria (Cyanobacteria) that form ammonia, which is toxic to plants; nitrification in which ammonia is converted into nitrites and nitrates with the help of Nitrobacter and denitrification bacteria involve Pseudomonas, and Achromobacter which convert nitrite and nitrate into nitrogen.
The lightning breaks nitrogen molecules and allow it to combine with oxygen in atmosphere which further dissolve in rain and form nitrates.
Hence, the nitrogen cycle is most directly dependent upon nitrogen-fixing bacteria and lightning and the correct option is B.
Answer:
Homeostatic control mechanisms have at least three interdependent components: a receptor, integrating center, and effector. ... The integrating center, generally a region of the brain called the hypothalamus, signals an effector (e.g. muscles or an organ ) to respond to the stimuli.
Explanation: