Answer: 4
(IV)
Explanation:
From the question, the researcher is interested in determining whether smiling and warmth impact the number of friends one has.
The variables are; Amount of smiling (a little, a lot) and self-rated warmth (cold, warm).
Manipulating the variables by the researcher or experimenter is called the free variables(IV). It is free to be varied. What is to be measured is called the dependent variable(∆V); it depends in the manipulation of free variables
Decomposition results in smaller and less complex systems that are easier to understand than larger, complicated systems.
<h3>
What is decomposition?</h3>
Decomposition, often known as rot, is the breakdown of dead organic matter into more basic organic or inorganic components such carbon dioxide, water, simple sugars, and mineral salts. The procedure, which is a component of the nutrient cycle, is crucial for recycling the limited amount of matter that takes up physical space in the biosphere.
<h3>What is Catabolism?</h3>
It's time to transform the trash into less complex inorganic compounds after the complex material has been broken down into tiny pieces and the inorganic nutrients have been eliminated. The process of catabolism is used by numerous bacterial and fungal enzymes to do this task.
<h3>What is
Humification?</h3>
It is the process by which humus, an amorphous layer with a dark color, forms on the soil. It is extremely resistant to the actions of bacteria, making it difficult to breakdown. The humus layer is particularly nutrient-rich because it gives the soil a high level of fertility.
Learn more about Catabolism:
brainly.com/question/13021229
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