Immunology and DNA Biology Lecture Review

Comprehensive vocabulary flashcards covering pathogens, immunology, DNA replication, DNA profiling techniques, and cell division processes.

Pathogen

Disease causing organisms such as bacteria, viruses, or fungi that cause disease in a host.

Keratin

A fibrous protein that provides strength and waterproofing to the top layer of the epidermis (stratum corneum).

Thrombin

An enzyme in the blood clotting cascade that cleaves soluble fibrinogen to form insoluble fibrin threads.

Insoluble fibrin mesh

The final structure that traps platelets and red blood cells to stabilize a clot and seal a wound.

Innate immune system

The part of the immune system present from birth, including skin, phagocytes, and inflammation, that does not require prior pathogen exposure.

Phagocytes

Specialized white blood cells, such as macrophages and neutrophils, that engulf and digest pathogens through phagocytosis.

Adaptive immune system

A pathogen-specific response involving antibodies and T-cell receptors that develops memory for faster future responses.

Thymus

The organ where T-lymphocytes migrate from the bone marrow to reach maturity and become functional.

Antigen

Molecules, often found on pathogens, that are recognized by the immune system and trigger the production of specific antibodies.

Blood group O

Known as the universal donor because these red blood cells lack A and B antigens, preventing transfusion reactions in any ABO blood group.

Memory B-cells

Long lived cells that can survive for decades to provide rapid immunity upon re-exposure to the same pathogen.

Helper T-cells

CD4+ T-cells required to recognize antigens and provide co-stimulatory signals to activate a naive B-cell.

AIDS

Acquired immunodeficiency syndrome; a condition of severely weakened immunity resulting from HIV destroying CD4+ T-cells.

Zoonotic disease

A disease that is transmitted from animals to humans, such as rabies, Ebola, or COVID-19.

Vaccines

Preparations containing harmless forms of antigens that mimic a pathogen to trigger a protective immune response without causing disease.

Herd immunity

Occurs when a significant portion of a population is vaccinated, making the majority immune and halting the spread of a pathogen.

Cilia

Small hair-like structures in the respiratory system that beat in waves to move mucus and trapped pathogens toward the throat.

Semi-conservative replication model

A model where each new DNA molecule consists of one original strand and one newly synthesized strand.

Helicase

An enzyme that unwinds the DNA double helix by breaking the internal base hydrogen bonds between complementary strands.

DNA polymerase

An enzyme that builds new strands of DNA by adding nucleotides to a growing strand using a template for complementarity.

PCR (Polymerase Chain Reaction)

A technique used for amplifying small DNA fragments into millions of copies of a specific DNA sequence.

Taq polymerase

A heat stable enzyme version derived from thermophilic bacteria that remains active at high temperatures ( $\approx 95 \, ^\circ \text{C}$ ) used in PCR.

Gel Electrophoresis

A technique where DNA fragments are separated by size and electrical charge as they move toward a positive pole.

Denaturation phase

The phase in PCR occurring at $98 \, ^\circ \text{C}$ where high heat breaks hydrogen bonds to separate DNA strands.

Annealing phase

The PCR phase where short DNA primer sequences bond to complementary template strands at temperatures between $50\text{--}65 \, ^\circ \text{C}$.

Restriction endonuclease

Special enzymes that recognize and cut DNA into shorter specific segments at or near specific sites.

Ethidium bromide

A fluorescent dye used to intercalate into DNA and visualize bands under UV light.

Wells

Small depressions molded into a gel where DNA samples are placed before electrophoresis.

Binary fission

The asexual process by which bacteria divide, involving cell growth, DNA duplication, and splitting into two identical cells.

Meiosis

A process that produces four genetically unique haploid sex cells (gametes) from diploid germ cells.

Cleavage furrow

A contractile ring that forms in animal cells to split the cytoplasm during division.

Cell plate

A visible structure that forms from Golgi vesicles in plant cells to develop into a new cell wall during cytoplasm division.

Oogenesis

The process of formation and maturation of female gametes (eggs) in the ovaries.

Synapsis

The process during prophase I of meiosis where homologous chromosomes pair up to form tetrads.