When two protein chains combine to form an active protein, the structural level is quaternary.
<h3>What is a quaternary structure?</h3>
The quaternary and tertiary structure of a protein is the tridimensional shape of the protein, which involves protein domains.
The quaternary protein structure refers to the different arrangements generated by different protein subunits.
The primary structure of a protein involves its amino acid sequence, whereas the second structure involves protein chains.
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Answer:
The steps that can be seen in this story are observation and the questioning phase, which can also be called elaboration of the problem.
Explanation:
The scientific method is a set of phases that are able to guide researchers to the creation of scientific knowledge, through an experiment. This method is essential for conducting scientific research, allowing an experiment to be managed in a way that promotes answers to scientists' questions. The scientific method presents the phases called observation, questioning (or elaboration of the problem), elaboration of hypotheses, experimentation, analysis of the results and conclusion.
In the story shown in the question above, we can see the phases called observation and questioning. The observation takes place the moment Fleming noticed a fungus capable of growing on colonies of bacteria that cause throat infections, killing them. This observation made him enter the questioning phase, when he wondered if the fungus was able to prevent the growth of these bacteria.
The shuffling of chromosomes that occurs during both fertilization and meiosis can lead to genetic variation. This is because of the independent assortment and crossing over. Hope this answers the question. Have a nice day. Feel free to ask more questions.