Unit 4 Cell Communication Cell Cycle

An open channel in the cell wall of plants through which strands of cytosol connect from adjacent cells

cells that process protein antigens and present them on their surface in a form that can be recognized by lymphocytes (white blood cells)

A functional subclass of T cells, which can help to generate cytotoxic T cells, cooperate with B cells in the production of antibody responses.

Cells that directly kill other cells, intracellular pathogens, or abnormal cells by releasing enzymes

ductless organ that makes hormones

substance/marker that triggers an immune response. It identifies the cell. They are highly specifc

General term for lymphocytes that are responsible for immunological memory and protective immunity.

proteins secreted by T cells to aid in antigen destruction and activate other T and B cells

produce antibodies

Protein that is produced by B cells and that attaches to a specific antigen.

the regulation of gene expression in response to fluctuations in cell-population density

conversion of the information encoded in a gene first into messenger RNA and then to a protein

a specialized cell transmitting nerve impulses; a nerve cell.

the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands