Bio 006 - 10A: Immune System III + Blood + Meiosis

Innate Immunity

General defense that does not remember pathogens.

Adaptive Immunity

Specific response that learns and remembers pathogens.

Humoral Immunity

Involves antibodies in body fluids.

Cell Mediated Immunity

Involves immune cells interacting with infected cells.

T Cells

Lymphocytes that recognize antigens on MHC molecules.

Cytotoxic T Cells

Kill infected cells by binding to MHC I → Clone self & kill host cell

Helper T Cells

Activate other immune cells by binding to MHC II.

Natural Killer Cells

Innate cells that kill infected or cancerous cells.

Antibodies

Proteins that bind to antigens to neutralize pathogens.

B Cells

Produce antibodies in response to antigens.

PAMPs

Pathogen-associated molecular patterns recognized by innate immunity.

MHC I

Presents antigens to Cytotoxic T Cells.

MHC II

Presents antigens to Helper T Cells.

Macrophages

Phagocytes that engulf and digest pathogens.

Neutrophils

Phagocytes (Leukocyte) that form DNA nets to trap pathogens.

Basophils

Leukocyte that release histamine during allergic reactions.

Monocytes

Differentiate into macrophages and dendritic cells.

Eosinophils

Leukocyte that combat multicellular parasites and allergic reactions.

Platelets

Cell fragments involved in blood clotting during injury

Stem Cells

Undifferentiated cells that can become various blood cells.

Lymphoid Stem Cells

Differentiate into lymphocytes (B & T Cells).

Myeloid Stem Cells

Differentiate into other blood cells, not lymphocytes.

Chromosome

Structure that packages DNA during cell division.

Allele

Variant forms of a gene on homologous chromosomes.

Example: B → brown eyes

b → blue eyes

Genotype

Combination of alleles for a specific gene.

Example: B allele & b allele → Bb

Character

Heritable feature that varies among individuals.

Examples: eye color, hair texture, height

(Each character has at least 2 possible alleles.)

Trait

Variant of a character

Examples: Blue eyes, curly hair, tall

(Comes from the combo of the 2 alleles; one from each homolog)

Phenotype

Observable expression of a trait.

Meiosis

Cell division producing four non-identical haploid cells.

Mitosis

Cell division producing two identical diploid cells.

Prophase I

Chromosomes condense and homologs pair up.

Crossing Over

Exchange of genetic material between homologous chromosomes.

Independent Assortment

Random distribution of chromosomes during gamete formation.

Erythrocytes

Red blood cells (RBC’s), transport oxygen. NOT a leukocyte

Leukocyte

White blood cells