Answer:
By action potential nerve contract the muscle
Explanation:
The muscle contract when the nervous system sends action potential to the muscle. So the nervous system delivers signal to muscle, the first signal reaches the neuromuscular junction. The signals are passed by a chemical messenger called neurotransmitter release by motor neurons, the chemicals bring reaction and shorten the muscle fibre. When neurotransmitter are absent or reduce in concentration the process reverse and muscle relax again.
Answer:
Lateral Hypothalamus
Explanation:
According to the hunger researchers' initial assumption lateral hypothalamus is that part of the brain which regulates intake of food and metabolical activities like metabolical regulation of peptides like the orexins melanin-concentrating hormone. It is that part of the brain that plays a key role in the ingestive behavior regulation.
The lateral hypothalamus system initiates physical and cognitive processes like it promotes arousal and feeding behavior, metabolism, regulates body temperature, BP, etc. and when stimulated it results in the feeding behaviour in animals as they begin to eat.
Proteins are a type of Macromedia and is made up of sub units that are called amino acids.
Answer:
Explanation:
A food chain only follows one path of what food animals eat. A food web consists of many food chains that show how plants and animals are connected. In conclusions, a food chain focuses on a certain animal or their path and they are linear. Food webs are more complex which show how the ecosystem works together to create a balance.
Answer:
The appearance of free oxygen in the Earth's atmosphere led to the Great Oxidation Event. This was triggered by cyanobacteria producing oxygen which developed into multicellular forms as early as 2.3 billion years ago
Explanation:
To clarify what I said here are some questions to help!
How did oxygen first appear?
Whiffs in the air is how oxygen first appeared billions of years ago.
For the most part, scientists agree that oxygen, though lacking in the atmosphere, was likely brewing in the oceans as a byproduct of cyanobacterial photosynthesis as early as 3 billion years ago
When was oxygen found?
2.33 billion years ago
Since its first appearance 2.33 billion years ago, oxygen accumulated in high enough concentrations to have a weathering effect on rocks just 10 million years later.
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