The sickle form of the hemoglobin gene is created when an adenine nucleotide is changed to a thymine. ... That single amino acid replacement in the -globin protein alters the shape and the chemistry of the hemoglobin molecule, causing it to polymerize and distort the red blood cell into the sickle shape.
Because an antibody is "made" relative to the antigen, but kept at low levels when you are exposed the first time ("primary immune response"). The second time you're exposed to the same antigen, memory cells recognize it and the body produces a high level of antibodies, and the level of antibodies usually remains higher for a longer time ("secondary immune response"). This is your basic immune response (primary and secondary).
This explains exactly why vaccines are effective to extremely effective.
We must first define these three prominent definitions of species. Biological species concept means that organisms resemble each other because of genes being passed from parent to offspring. Phylogenetic species concept means that organisms resemble each other because they evolved from a common ancestor. Lastly, morphological species concept characterizes species on the structure of their body parts rather than genetic or phylogeny.
In this case, (1) biological species concept is not applicable for extinct species, (2) phylogenetic species concept is based on evolutionary history, (3) morphological species concept relies on similarities in structure, (4) Morphological and phylogenetic species concept accommodates asexual reproduction, and lastly (5) all species concepts are used by scientists in classification.
Answer:
Microtubules play an important role in cell division by contributing to the formation of the mitotic spindle, which plays a part in the migration of duplicated chromosomes during anaphase.
