Influenza Set

Influenza Virus

A virus that infects epithelial cells in the respiratory system, causing influenza. Types include Influenza A, B, C, and D.

Virus

A microscopic infectious agent that requires a host cell to replicate. Composed of genetic material (DNA or RNA) enclosed in a capsid.

Genetic Material

The DNA or RNA that carries a virus's genetic instructions for replication.

Capsid

The protein shell surrounding the genetic material of a virus. Contains proteins that aid in attachment to host cells.

Envelope

A lipid layer derived from the host cell membrane, surrounding some viruses like Influenza. Helps the virus enter new cells.

Spikes

Glycoproteins on the surface of influenza viruses (H and N spikes) that assist with cell attachment and entry.

Giant Viruses

Viruses much larger than typical viruses, almost the size of small bacteria.

Lytic Cycle

The viral replication process where the virus immediately uses host cell machinery to produce new viruses, eventually lysing (bursting) the host cell.

Lysogenic Cycle

The viral replication process where viral DNA integrates into the host genome and remains dormant until triggered.

Epithelial Cells

Cells lining the respiratory system targeted by influenza viruses.

Flu Vaccine

A vaccine designed to protect against multiple influenza strains, made from inactivated viruses or recombinant proteins.

Recombinant Process

A method of producing vaccines using only a specific viral protein, often using insect cells.

Evolution

The process of change in populations over time through genetic variation and natural selection.

Natural Selection

The mechanism where individuals with advantageous traits are more likely to survive and reproduce, spreading those traits.

Stabilizing Selection

Selection that favors average traits, reducing extremes.

Directional Selection

Selection that favors one extreme trait, shifting population characteristics.

Disruptive Selection

Selection that favors both extreme traits over average traits, possibly splitting populations into two groups.

Information Flow

The central dogma of molecular biology: DNA → RNA → Protein.

Fossil Record

Mineralized remains of organisms providing evidence for evolution.

Analogous Structures

Structures that perform similar functions but evolved independently (e.g., bird wings vs insect wings).

Homologous Structures

Structures inherited from a common ancestor (e.g., vertebrate limb bones).

Antigenic Drift

Small mutations in influenza spikes over time, reducing vaccine effectiveness.

Antigenic Shift

Major genetic changes when two viruses infect the same cell, creating a new hybrid virus.

Lymphatic System

A network of tissues and organs that returns fluid to the blood and helps the immune system fight infection.

Immune System

The body’s defense system against pathogens, involving innate and adaptive responses.

Major-Histocompatibility Complexes (MHC)

Self-identification glycoproteins on cells.

Antigen

A molecule, usually a protein, that triggers an immune response.

Macrophages

Immune cells that engulf pathogens and present antigens to T cells.

Dendritic Cells

Immune cells that present antigens to activate T cells.

Innate Defenses

General, non-specific immune defenses like barriers, inflammation, and phagocytosis.

Cytokines

Chemical signals that coordinate immune responses.

Inflammatory Response

A process where tissue damage triggers histamine release, increasing blood flow and white blood cell recruitment.

Neutrophils

White blood cells that engulf pathogens and debris.

Adaptive Immunity

Specific immunity that targets particular pathogens and retains memory of past infections.

Cell-mediated Immunity

Immune response targeting infected cells using T cells.

Targeting Infected Cells

Cytotoxic T cells recognize infected cells displaying antigens and destroy them.

Core Proteins

Internal viral proteins that mutate less and could be used for universal vaccines.