Answer:
transcription
Explanation:
transcription is the process of transferring genetic Instructions from the DNA to mRNA if the necleus
The first step in the formation of the human embrayo and it is called fertilization.
<h3>What is fertilization?</h3>
The first step in the formation of a human embrayo is called fertilization. The term fertilization has to do with fusion of the male and female gametes to form a zygote.
Hence, the diagram as shown is the first step in the formation of the human embrayo and it is called fertilization.
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These alveoli are the smallest types of lung tissue, and one of the most important. In addition to being the primary means by which oxygen enters and carbon dioxide escapes the bloodstream, these small pouches of air are also the reason why the lungs do not totally collapse when a person breathes out. This is because they contain a cell that secretes a special chemical to lower the surface temperature to prevent lung collapse. The alveoli also contain other cells that secrete chemicals to attack and remove any foreign objects in the lungs, such as dust, dirt and other debris.
In addition to making up alveolar sacs, alveoli also form alveolar ducts. It is estimated that there are more than 300 million alveoli in the human lungs, all of which are located in either alveolar ducts or sacs that are found at the end of the smaller passageways, or bronchioles, in the lungs.
SHORT ANSWER:
Alveolar sacs contain tiny pouches called alveoli, whose primary function is gas diffusion. These clusters of alveoli have thin walls that allow oxygen to pass easily from the lungs into the bloodstream and carbon dioxide to flow from the blood to the lungs so it can exit the body.