Honors Biology Final Exam Study Guide

Comprehensive vocabulary flashcards covering key concepts from Honors Biology including chemistry, cell biology, physiology, genetics, ecology, and evolution.

Polar Molecule

A molecule characterized by an unequal distribution of electrical charge, such as water ($H_2O$), having distinct partial positive ($+$) and partial negative ($-$) charges.

Hydrophilic

A characteristic of "water-loving" substances, such as salts, that are attracted to partial charges and dissolve easily in water.

Nonpolar Molecule

A molecule that does not have regions of positive or negative charges and is hydrophobic (insoluble in water), such as lipids.

Nucleic Acids

Organic molecules composed of nucleotides, including DNA and RNA, that store and transmit hereditary information.

Proteins

Organic molecules made of sequences of amino acids that speed up reactions (enzymes), transport oxygen, and form cell membrane surface markers.

Lipids

Non-polar, hydrophobic organic molecules used for long-term energy storage and making up cell membranes; includes fats and phospholipids.

Carbohydrates

Organic molecules built from sugars that provide the primary source of chemical energy to living organisms.

Monomer

A single building block that can join with others to form more complex molecules.

Polymer

A complex molecule consisting of many monomers bonded together.

Organic Molecule

A molecule that specifically contains carbon and hydrogen atoms.

CHNOPS

The most important elements in living things: Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur.

Catalyst

A substance, such as an enzyme, that increases the rate of a chemical reaction without being consumed in the process.

Substrate

The specific reactant molecule that an enzyme binds to due to their matching physical 3D shapes.

Denaturation

A process where a protein's structure is altered by heat or pH, causing it to lose its biological biological structure and function.

Cell Theory

A fundamental set of tenets: 1. All living things are made of cells; 2. Cells are the smallest units of life; 3. All cells come from preexisting cells.

Eukaryotic Cells

Complex cells that possess a membrane-bound nucleus and membrane-bound organelles with DNA organized into chromosomes.

Prokaryotic Cells

Simpler cells that lack a nucleus and membrane-bound organelles; their DNA consists of a chromosome located in the cytoplasm.

Simple Diffusion

A form of passive transport where molecules move randomly from an area of high concentration to an area of low concentration.

Osmosis

The movement of water across a membrane; in plant cells, the rigid cell wall prevents rupture from osmotic pressure in hypotonic environments.

Active Transport

The movement of molecules against the concentration gradient (low to high) requiring ATP; includes phagocytosis and protein pumps.

Negative Feedback Loop

A process where the product of a reaction reduces the initial stimulus to maintain stability, such as insulin lowering blood glucose.

Homeostasis

The maintenance of a stable internal environment despite external changes.

Reflex Arc

An involuntary sequence involving a Sensory Receptor, Sensory Neuron, Spinal Cord, and Motor Neuron to produce a near-instantaneous movement.

Endocrine System

The body system that communicates via hormones traveling through the blood for slower but longer-lasting effects.

Nephron

The functional unit of the kidney responsible for filtering blood and forming urine.

ATP (Adenosine triphosphate)

The universal energy currency molecule that provides energy for nearly all cellular activities.

Cellular Respiration

An aerobic process occurring in the mitochondria that converts stored chemical energy (glucose) into ATP.

Mitochondria

The "powerhouse" organelle where cellular respiration and ATP production occur.

pH Scale

A measure of how acidic or basic a solution is, ranging from 0 (acidic) to 14 (basic).

Base Pairing

The specific hydrogen bonding between nitrogenous bases in DNA: Adenine (A) with Thymine (T) and Guanine (G) with Cytosine (C).

Mitosis

Cell division resulting in 2 genetically identical diploid ($2n$) body (somatic) cells for growth and repair.

Meiosis

Cell division resulting in 4 genetically different haploid ($n$) sex cells (gametes) for sexual reproduction.

Haploid

A cell containing only one set of chromosomes ($n$).

Diploid

A cell containing two sets of chromosomes, one from each parent ($2n$).

Codominance

An inheritance pattern where neither allele is dominant, and both are expressed equally, such as black and white speckled chickens.

Incomplete Dominance

Also called intermediate inheritance, where neither allele is dominant, resulting in a blend (e.g., gray chickens from white and black parents).

Genotype

The actual genetic makeup or alleles present in an organism (e.g., Gg).

Phenotype

The observable trait or physical characteristics of an organism.

Transcription

The process occurring in the nucleus where a segment of DNA is copied into mRNA.

Translation

The process at the ribosome where the information in mRNA is used to synthesize a specific protein.

Greenhouse Effect

The trapping of the sun's warmth in the lower atmosphere due to heat-absorbing gases like $CO_2$.

Carrying Capacity

The maximum population size an environment can support based on available resources.

10% Rule

The principle that only about 10% of the energy at one trophic level is transferred to the next; 90% is lost as heat or waste.

Mutualism

A symbiotic relationship ($+/+$) where both organisms benefit.

Parasitism

A symbiotic relationship ($+/-$) where one organism benefits and the other is harmed.

Commensalism

A relationship ($+/0$) where one species benefits and the other is neither helped nor harmed.

Natural Selection

The primary mechanism of evolution where organisms with advantageous traits are more likely to survive and reproduce.

Homologous Structures

Body parts that share a similar underlying structure due to common ancestry, even if they serve different functions.

Vestigial Structures

Remnants of organs, like the human appendix, that were functional in ancestral species but are mostly non-functional today.

Binomial Nomenclature

The two-term naming system for species consisting of the Genus followed by the specific epithet.

Cladogram

A branching diagram illustrating hypothetical evolutionary relationships based on shared, derived characteristics.