<span>the intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment.
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Natural selection is the process in which the more favorable traits due to mutation that are in a select few in a population produce more offspring then others. An example of this is bacteria resistant to antibiotics due to the faster reproduction of the resistant bacteria over the non resistant ones
I think the third one is the answer
1. Carbohydrates
(There are 3 sources of calories (or energy), which are also known as macronutrients: carbohydrates, protein, and fat.
Of these three, carbohydrates are the body’s preferred source of energy. Carbohydrates break down into glucose, which is an immediate source of energy.)
2.
A. Bone is not a type of human body tissue.
(The human body does has 4 types of tissue: Epithelial, muscle, connective and nervous tissue).
Answer:
Bacteria
Explanation:
Bacteria have no true nucleus because it's a prokaryote. It couldn't have been a virus because all naturally occurring viruses are pathogenic unless treated by radiation.
We have two types of bacteria,
- Pathogenic
- Commensals
Pathogenic bacteria will definitely cause disease. Commensals, however, have don't harm us and have the ability to help us.
Eg: Flora (bacteria) in our intestines produce vitamin K and most of the vitamin B complex. They also compete with the pathogenic bacteria that you might've ingested and don't allow them to increase to the number that can cause disease.