Changes in the trilobite exoskeleton can be attributed to

Proteins are made from amino acids. an amino acid has three parts that are joined to a central carbon atom. identify the three parts that create an amino acid.

The allele for curly hair is incompletely dominant. if a mother is homozygous for curly hair and the father is homozygous for straight hair, what percentage of the offspring will exhibit characteristics of both parents? 25 percent 50 percent 75 percent 100 percent

Which is an advantage of having memory cells when a pathogen is encountered for a second time. a) the memory cells are what proliferate into clones of cells in response to the binding of an antigen. b) memory cells are vital to the primary immune response in that they immediately recognize pathogens even at the first encounter. c) memory cells are essentially effector cells that are short lived and attack antigens even without having a receptor specific to that antigen. d) it ensures that more lymphocytes with a receptor specific to a particular antigen will be present than in a host that had never encountered that pathogen.