Helper T cells <span>are required for almost all </span>adaptive immune responses<span>. They not only help activate B </span>cells to<span> secrete antibodies and macrophages </span>to<span> destroy ingested microbes, but they also help activate cytotoxic </span>T cells to<span> kill infected target </span>cells<span>.</span>
Answer:
invertebrates. animal's without backbone.
verterbrates- animals with backbone
The central communication conduit
between the brain and the rest of the body is the spinal cord. The spinal cord
is a long thin structure that comes from medulla oblongata in the brain stem to
the bottom of the spine. The spinal cord is made up of nerves that transmit messages
between the brain and the rest of the body.
Each of the term is identified whether they arise from the ectoderm, mesoderm or the endoderm.
The thyroid arises from the endoderm.
The thymus arises from the ectoderm.
The anterior pituitary arises from the ectoderm.