D is the answer
It’s cell,tissue,organ, organ system
<span>Basically, the body needs to know what it is defending against. Your body can still (usually) fight off infection, even without an immunization, but it takes longer. Basically, your body creates cells with a receptor for a specific disease. When this cell finds the disease it is programmed for, it will send out signals to the "killer" cells to come and kill it. If your body doesn't have the "seeker" cells, it can't fight off the infection until it does. The opposite end are autoimmune diseases, where your immune system starts attacking itself.
brainlest answer</span>
Answer:
Translation is the process of translating the sequence of a messenger RNA (mRNA) molecule to a sequence of amino acids during protein synthesis. The genetic code describes the relationship between the sequence of base pairs in a gene and the corresponding amino acid sequence that it encodes.
The most recent and arguably best-known, the Cretaceous–Paleogene extinction event, which occurred approximately 66 Ma (million years ago), was a large-scale mass extinction of animal and plant species in a geologically short period of time.
Answer: Examples of beneficial mutations are HIV resistance, lactose tolerance, and trichromatic vision.