Answer:
A
Explanation:
The term "phenotype" refers to the observable physical properties of an organism; these include the organism's appearance, development, and behavior. An organism's phenotype is determined by its genotype, which is the set of genes the organism carries, as well as by environmental influences upon these genes.
The backpack's main force that it it is exerting on the body's back and hips is coming from gravity, and can pull the spine downwards. This is why it's important to ear both straps.
The first line of defense of the immune system includes mechanical barriers that prevent organisms from the body. The second line of defense includes processes that help remove or neutralize organisms that have penetrated mechanical barriers. The third line of defense is a complex defense that recognizes and reacts to specific organisms.
I believe this is true. However, too much strain on the muscle will cause it to become damaged, so always put strain on your muscles in moderation.
