Semester 2 Final Exam Study Guide: Honors Biology of the Living Earth

Comprehensive vocabulary flashcards covering Evolutionary Principles, Cellular Energetics, Inheritance of Traits, DNA Structure/Replication, Protein Synthesis, Biotechnology, Biochemistry, Cell structure, and Ecosystem Interactions.

Natural Selection

The process by which organisms with variations most suited to their local environment survive and leave more offspring.

Artificial Selection

The process where nature provides the variations, and humans select those they find useful.

Adaptation

Any heritable characteristic that increases an organism's ability to survive and reproduce in its environment.

Acquired Traits

Traits gained by an organism during its lifetime through use or disuse, which are not passed on to offspring.

Heritable Traits

Characteristics passed from parents to their offspring through genes.

Genetic Variation

The differences in DNA among individuals or the differences between populations, produced by mutation and genetic recombination.

Directional Selection

A type of natural selection in which individuals at one end of the curve have higher fitness than individuals in the middle or at the other end.

Stabilizing Selection

A type of natural selection in which individuals near the center of the curve have higher fitness than individuals at either end.

Disruptive Selection

A type of natural selection in which individuals at the upper and lower ends of the curve have higher fitness than individuals near the middle.

Genetic Drift

A random change in allele frequency that occur in small populations.

Speciation

The formation of a new species.

Isolating Mechanisms

Barriers such as reproductive, behavioral, geographic, or temporal isolation that prevent two populations from interbreeding and lead to speciation.

Adaptive Radiation

The process by which a single species or a small group of species evolves into several different forms that live in different ways.

Coevolution

The process by which two species evolve in response to changes in each other over time.

Convergent Evolution

The process by which unrelated organisms independently evolve similarities when adapting to similar environments.

Phylogeny

The evolutionary history of lineages.

Ecomorph

A term used to describe species with similar body types and habitats, such as those found among anole lizards in the Caribbean.

Taxonomy

A system of naming and classifying organisms based on shared characteristics and universal rules.

Hardy-Weinberg Principle

The principle stating that allele frequencies in a population should remain constant unless one or more factors cause those frequencies to change.

Cladogram

A diagram that links groups of organisms by showing how evolutionary lines, or lineages, branched off from common ancestors.

Derived Characters

A trait that arose in the most recent common ancestor of a particular lineage and was passed along to its descendants.

Outgroup

An organism used in a cladogram that is distantly related to the other organisms and lacks the derived characters being studied.

ATP

Adenosine triphosphate; the compound used by cells to store and release energy.

Metabolism

The combination of chemical reactions through which an organism builds up or breaks down materials.

Overall Equation for Photosynthesis

$$6CO_2 + 6H_2O + \text{light} \rightarrow C_6H_{12}O_6 + 6O_2$$

Overall Equation for Respiration

$$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{ATP}$$

Aerobic Cellular Respiration Steps

The process including Glycolysis, the Krebs cycle, and the Electron Transport Chain.

Mendelian Genetics

The study of inheritance based on the principle of dominance, independent assortment, and probability.

Trait

A specific characteristic, such as seed color or plant height, of an individual.

Gene

A sequence of DNA that codes for a protein and thus determines a trait.

Allele

One of a number of different forms of a gene.

Homozygous

Having two identical alleles for a particular gene.

Heterozygous

Having two different alleles for a particular gene.

Genotype

The genetic makeup of an organism (e.g., $TT$ or $Tt$).

Phenotype

The physical characteristics of an organism (e.g., tall or short).

Monohybrid Cross

A genetic cross involving a single trait.

Dihybrid Cross

A genetic cross involving two different traits.

Codominance

A situation in which the phenotypes produced by both alleles are clearly expressed.

Incomplete Dominance

A situation in which one allele is not completely dominant over another, resulting in a phenotype that is a blend.

Polygenic Traits

Traits controlled by two or more genes.

Meiosis

A process in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell.

Homologous

Term used to refer to chromosomes in which one set comes from the male parent and one set comes from the female parent.

Diploid

A cell that contains both sets of homologous chromosomes ($2n$).

Haploid

A cell that contains only a single set of genes ($n$).

Tetrad

The structure formed during meiosis when each replicated chromosome pairs with its corresponding homologous chromosome.

Crossing-over

The process in which homologous chromosomes exchange portions of their chromatids during meiosis I.

Gamete

A specialized cell involved in sexual reproduction (sex cells).

Nucleotide Structure

A building block of DNA or RNA consisting of a 5-carbon sugar, a phosphate group, and a nitrogenous base.

Purines

Double-ring nitrogenous bases, such as adenine ($A$) and guanine ($G$).

Pyrimidines

Single-ring nitrogenous bases, such as cytosine ($C$), thymine ($T$), and uracil ($U$).

Transcription

The process of copying a base sequence from DNA to RNA.

Translation

The process of decoding an mRNA message into a protein.

Biotechnology

The application of a technological process, invention, or method to living organisms.

Gel Electrophoresis

A procedure used to separate and analyze DNA fragments by placing a mixture of DNA fragments at one end of a porous gel and applying an electrical voltage.

Bacterial Transformation

The process by which one strain of bacteria is changed by a gene or genes from another strain of bacteria.

Subatomic Particles

Protons, neutrons, and electrons that make up an atom.

Enzymes

Protein catalysts that speed up the rate of specific biological reactions by lowering activation energy.

Eukaryotic Cells

Cells that enclose their DNA in nuclei.

Prokaryotic Cells

Cells that do not enclose DNA in nuclei.

Phospholipid Bilayer

A double-layered sheet that forms the core of nearly all cell membranes.

Passive Transport

The movement of materials across the cell membrane without using cellular energy.

Active Transport

The movement of materials against a concentration difference, requiring energy.

Diffusion

The process by which particles move from an area of high concentration to an area of lower concentration.

Osmosis

The diffusion of water through a selectively permeable membrane.

Cell Cycle Stages

The series of events that cells go through as they grow and divide, typically including G1, S, G2, and M phases.

Cell Division

The process by which a cell divides into two new daughter cells.

Abiotic Factors

Nonliving parts of an ecosystem, such as sunlight, heat, precipitation, and soil type.

Biotic Factors

Living parts of an ecosystem with which an organism might interact.

Niche

The range of physical and biological conditions in which a species lives and the way the species obtains what it needs to survive and reproduce.

Carrying Capacity

The maximum number of individuals of a particular species that a particular environment can support.

Immigration

The movement of individuals into an area.

Emigration

The movement of individuals out of an area.

Binomial Nomenclature

The two-word naming system for organisms, consisting of the genus and the species name.