History of Biotechnology, Selective Breeding, and Microorganisms

Comprehensive vocabulary flashcards covering the historical development of biotechnology, plant and animal selective breeding, fermentation, pasteurization, antibiotic discovery, and common microorganisms (bacteria, viruses, and fungi).

Modern Biotechnology (1953 Discovery)

The era of biotechnology catalyzed in 1953 when James Dewey Watson and Francis Harry Compton Crick discovered that DNA functions as genetic material.

Domestication

According to the National Geographic Society Encyclopedia, the process of adapting wild plants and animals for human use (such as food, work, clothing, and medicine), requiring them to be raised and cared for by humans.

Domestication Timeline

The chronological record of early domestication: $10{,}000\text{ BC}$ (dog), $9{,}800\text{ BC}$ (wheat, chick peas, beans, sheep, goats, pig), $8{,}500\text{ BC}$ (barley), $7{,}000\text{ BC}$ (cattle), $6{,}800\text{ BC}$ (rice), and $3{,}000\text{ BC}$ (horse, cat).

Natural Selection

The evolutionary principle established by 19th-century British naturalist Charles Darwin in On the Origin of Species, describing the process by which adaptive traits are handed down over time.

Selective Breeding (Artificial Selection)

The intentional breeding of animals or plants for specific, desirable traits so that the underlying genes are passed down to offspring.

Variation

The biological phenomenon in which all offspring look slightly different from their parents, providing the raw material for selective breeding.

Pure Line Selection

A plant breeding procedure wherein individuals of a given population exhibiting desired traits are selected and isolated for further breeding and cultivation.

Hybridization (Plants)

The breeding method of combining desired traits found in different plant lines to produce individual plants that exhibit both traits simultaneously.

Heterosis

The phenomenon of increased vigor obtained by the hybridization of inbred plant lines.

Polyploidy

The condition of possessing an increased number of chromosome sets, used as a procedure to contribute to crop improvement.

Broccoflower and Tangelo

Examples of plant hybrids produced by artificial selection: broccoflower is a cross between broccoli and cauliflower, and tangelo is a hybrid of a tangerine and a grapefruit.

Breed

In livestock, a population expressing a specific combination of inherited traits that distinguishes it from the rest of the species.

Pure Breeding (True Breeding)

A breeding system where parents are homozygous (carrying two identical alleles for a particular gene) and produce offspring with the same phenotype across generations, such as Aberdeen Angus cattle.

Crossbreeding

The mating of animals from two different breeds to combine complementary traits and enhance offspring economic value, such as crossing high-quality beef Angus with large-sized Charolais cattle.

Inbreeding

The mating of closely related animals to concentrate desirable traits and narrow the genetic base, frequently applied to laboratory mice and rats to produce uniform experimental responses.

Biological Leaver

A substance (such as yeast, baking powder, or baking soda) that causes baked products to expand or rise; derived from the Latin word levare, meaning 'lift up, to make light and rise.'

Fermentation (Anaerobic Respiration)

A cellular process in which living cells obtain energy through the breakdown of glucose and other simple sugars without requiring oxygen.

Glycolysis

The first step of fermentation in which glucose is split into pyruvate by bacterial or yeast enzymes, yielding $2\,\text{ATP}$.

Lactic Acid Fermentation vs. Alcohol Fermentation

The two primary types of fermentation: alcohol fermentation uses yeast to split pyruvate into alcohol and carbon dioxide, while lactic acid fermentation uses bacteria to convert pyruvate into lactic acid.

Pasteurization

A food preservation process developed in 1864 by Louis Pasteur (heating wine to $50\text{--}60\,^{\circ}\text{C}$ or $122\text{--}140\,^{\circ}\text{F}$) to kill spoilage microbes and pathogens and inactivate enzymes without significantly diminishing nutrient levels.

Historical Precursors of Pasteurization

Early thermal food preservation methods used in China ($1117\text{ AD}$ for wine), by Lazzaro Spallanzani ($1768$, boiled broth in sealed containers), Nicolas Appert ($1795$, canning in glass jars), Peter Durand ($1810$, tin canning), and Franz von Soxhlet ($1886$, suggested pasteurization of milk).

Modern Non-Thermal Pasteurization Processes

Advanced commercial pasteurization methods that disinfect food without prolonged heat, including high-pressure processing (HPP or pascalization), microwave volumetric heating (MVH), and pulsed electric field (PEF) pasteurization.

Penicillin Discovery (1928)

The identification of the antibiotic penicillin by Sir Alexander Fleming after mold (Penicillium notatum) contaminated a culture plate and inhibited surrounding Staphylococcus bacteria growth.

Howard Florey and Ernst Chain

The two scientists who developed methods to produce large quantities of penicillin in $1940$, proved its effectiveness in mice, treated the first human patient (Albert Alexander), and shared the $1945$ Nobel Prize for Medicine with Alexander Fleming.

Bacteria

Single-celled prokaryotic organisms existing in rod, sphere, or spiral shapes that feature a peptidoglycan cell wall, a plasma membrane, a circular chromosome, and sometimes flagella, plasmids, capsules, or pili.

Plasmid

A small, circular extra-chromosomal DNA piece found in bacteria that carries a small number of genes independent of the primary chromosome.

Pili

Hairlike protein appendages emerging from the bacterial surface that assist in adhering to surfaces and bridge the transfer of DNA between bacteria.

Streptomyces

A filamentous, soil-dwelling bacterial genus utilized in modern biotechnology for producing antibiotics such as streptomycin and chloramphenicol.

Virus

The smallest type of microbe, consisting of an inner core of nucleic acid (DNA or RNA) enclosed in a protein capsid, considered nonliving because it can reproduce only inside a host cell.

Bacteriophage

A specialized virus that infects bacteria, utilized in biotechnology as an antibacterial agent and as a vehicle for delivering DNA to drive bacterial adaptive evolution.

Hyphae and Mycelium

The structural units of multicellular fungi: hyphae are threadlike filaments developing from spores, and the intertwined network of hyphae forms the fungal body known as the mycelium.

Saccharomyces

A unicellular fungal genus meaning 'sugar fungi' that reproduces by budding and serves as the primary yeast used in bread baking and beer brewing.