Biology Practice Flashcards: Genetics, Water Properties, Soils, Adaptation & Physiology

Comprehensive vocabulary flashcards covering genetic processes, aquatic properties, plant photosynthetic pathways, soil science, evolutionary concepts, and physiological adaptations.

Gene Pool

Alleles from all genes of every individual in a population.

Genetic Drift

Loss of genetic variation due to random variation in mating, mortality, fecundity, or inheritance; more common in small populations.

Bottleneck Effect

Occurs when a population experiences a severe reduction in size, making it more vulnerable to pathogens.

Founder Effect

Phenomenon where a small group leaves a population and carries only a small amount of genetic variation.

Stabilizing Selection

Type of natural selection in which intermediate phenotypes survive more than extreme phenotypes.

Directional Selection

Type of selection in which an extreme phenotype achieves better fitness than normal phenotypes.

Disruptive Selection

Type of selection in which both extreme phenotypes achieve better fitness than intermediate phenotypes.

Allopatric Speciation

Evolution of a new species resulting from geographic isolation.

Sympatric Speciation

Evolution of a new species occurring without geographic isolation.

Polyploid

An organism or cell containing 3 sets of chromosomes due to a failure to separate during meiosis or mitosis.

Specific Heat

The amount of heat required to raise the temperature of water by $1^\circ\text{C}$.

Viscosity

The thickness of a fluid that causes resistance to objects moving through it.

Osmotic Potential

The force of a solution attracting $\text{H}_2\text{O}$, measured in Megapascals ($\text{MPa}$).

Hyperosmotic

Describing tissues that have a higher solute concentration than surrounding water (e.g., freshwater organisms).

Hyposmotic

Describing tissues that have a lower solute concentration than surrounding water (e.g., saltwater whales).

Boundary Layer

An area of unstirred air or water surrounding the surface of an object that slows down diffusion.

Countercurrent Circulation

Arrangement where two fluids move in opposite directions across a barrier to exchange heat or other materials.

Homeotherms

Organisms that maintain a constant body temperature in their cells.

Poikilotherms

Organisms that do not maintain constant body temperatures.

Thermal Optimum

The temperature at which an organism's performance is best, determined by enzymes, lipids, cell and tissue structure, and body form.

Parent Material

The bedrock underlying soil that determines the soil type.

Leaching

Process by which groundwater dissolves and moves compounds deeper into the soil.

Matric Potential

Potential energy generated by attractive electrical forces between water molecules and the matrix of soil particles.

Field Capacity

The maximum amount of water soil can hold against the force of gravity.

Wilting Point

The lowest water potential at which plants can still extract water from the soil.

Cation Exchange Capacity

The ability of soil to retain positively charged ions (cations).

Cohesion-Tension Theory

The theory explaining water movement from roots to leaves driven by water cohesion and transpiration tension.

Photorespiration

Reaction occurring when rubisco binds to $\text{O}_2$ instead of $\text{CO}_2$ due to $\text{O}_2$ accumulation, producing $\text{G3P}$ and 2-phosphoglycolate.

PEP Carboxylase

An enzyme in $\text{C}_4$ photosynthesis that catalyzes the reaction between $\text{CO}_2$ and PEP, possessing a higher affinity for $\text{CO}_2$ than rubisco.

CAM Photosynthesis

Photosynthetic pathway (Crassulacean acid metabolism) used by succulents in water-stressed environments that open stomata at night to minimize transpiration.

Greek Essentialism

Philosophical view stating that variation exists because organisms are imperfect copies of a perfect form.

Uniformitarianism

Principle stating that physical processes occurring in the present are the same as those in the past and produced past landscapes.

Neo-Darwinism

Modern evolutionary theory defining evolution as heritable variation multiplied by selection.

Phenotypic Plasticity

The ability of a single genotype to produce multiple phenotypes.

Phenotypic Trade-off

A condition where a phenotype offers high fitness in one environment but poor fitness in others.

Diapause

Partial or complete physiological body shutdown in insects in response to adverse conditions.

Torpor

A brief period of dormancy used by organisms like birds to survive extreme environmental variation.

Aestivation

The shutting down of metabolic processes during summer, seen in animals such as crocodiles.

Optimal Foraging Theory

Theory describing foraging behavior as a balance between benefits and energy or risk costs.

Handling Time

The amount of time a predator takes to consume a captured prey item.

Negative Feedback

A mechanism where a system acts in response to a deviation from a desired state to restore homeostasis.

Thermal Inertia

Resistance to body temperature change resulting from having a large body volume.

Blood Shunting

Process where blood vessels shut off at precapillary sphincters so less exterior heat loss occurs.