BIO EXAM TOPICS

Scientific Method

A systematic process for conducting experiments and making observations.

Independent Variable

The variable that is manipulated in an experiment to test its effects.

Dependent Variable

The variable that is measured or observed in an experiment.

Major Elements of Life

Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, and Sulfur.

Atomic Number

The number of protons in the nucleus of an atom, determining its chemical properties.

Isotopes

Variants of a particular chemical element that have the same number of protons but different numbers of neutrons.

Properties of Water

Cohesion, adhesion, high specific heat, universal solvent, and density.

Chemical Bonds

Forces holding atoms together, including ionic, covalent, and hydrogen bonds.

Biological Molecules

Four major groups include carbohydrates, lipids, proteins, and nucleic acids.

Monomers and Polymers

Monomers are building blocks; polymers are chains of monomers.

Dehydration Synthesis

The process that links monomers by releasing water.

Hydrolysis

The process that breaks down polymers into monomers by adding water.

Prokaryotic Cells

Cells without a nucleus or membrane-bound organelles.

Eukaryotic Cells

Cells containing a nucleus and membrane-bound organelles.

Plasma Membrane

A cell boundary that regulates the entry and exit of substances.

Endomembrane System

Network of membranes involved in synthesis, storage, and transport.

Nucleus

The membrane-bound organelle that contains DNA.

Potential Energy

Energy stored in an object due to its position or arrangement.

Kinetic Energy

Energy of motion.

Thermodynamics Laws

Principles governing energy transfers; includes conservation of energy and entropy.

Enzymes

Biocatalysts that speed up chemical reactions without being consumed.

Passive Transport

Movement of molecules across a membrane without energy input.

Diffusion

Movement of molecules from an area of high concentration to low concentration.

Facilitated Diffusion

a passive transport process that moves molecules or ions across a cell membrane with the help of specialized proteins

Cellular Respiration

The process by which cells convert glucose and oxygen into energy, with the equation: C6H12O6 + O2 → CO2 + H2O + ATP.

Aerobic Respiration

Cellular respiration that uses oxygen.

Anaerobic Respiration

Cellular respiration that occurs without oxygen.

Stages of Cellular Respiration

Include Glycolysis, Krebs Cycle, and Oxidative Phosphorylation.

Photosynthesis Equation

6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2.

Photosystem

Protein and pigment complex involved in the light reactions of photosynthesis.

Light Reactions

The first stage of photosynthesis that converts solar energy into chemical energy.

Calvin Cycle

The second stage of photosynthesis that synthesizes glucose from carbon dioxide.

Chromosomes

thread-like structure located inside the nucleus of a cell, composed of DNA tightly coiled around proteins, which carries genetic information in the form of genes, passed from parents to offspring

Chromatids

Identical halves of a duplicated chromosome.

Stages of Mitosis

Prophase, Metaphase, Anaphase, Telophase; stages in cell division.

Human Chromosome Number

Humans have 46 chromosomes, arranged in 23 pairs.

Stages of Meiosis

Include Prophase I, Metaphase I, Anaphase I, Telophase I, followed by Meiosis II.

Genetic Recombination

Genetic variation that occurs during meiosis, especially in Prophase I.

Nondisjunction

The failure of chromosomes to separate properly during cell division.

Genes

Segments of DNA that encode for proteins and determine traits.

Alleles

Different versions of a gene.

Homozygous

Having two identical alleles for a given gene.

Heterozygous

Having two different alleles for a given gene.

Genotype

The genetic makeup of an organism.

Phenotype

The observable characteristics or traits of an organism.

Mendel's Laws

Principles of inheritance proposed by Gregor Mendel, including the law of segregation and independent assortment.

Genetic Cross

Breeding experiment that measures trait inheritance.

Sex-linked Inheritance

Inheritance patterns associated with genes located on sex chromosomes.

Epigenetics

Study of heritable changes in gene expression without alterations to the DNA sequence.

DNA Structure

Composed of nucleotides, each containing a phosphate group, sugar, and nitrogenous base.

RNA Structure

Single-stranded molecule composed of ribonucleotides.

Complementary Base Pairing

A-T and G-C bonding in DNA/RNA.

Transcription

The process of synthesizing RNA from a DNA template.

Translation

The process of synthesizing proteins from mRNA.

RNA Processing

Modification of RNA before it can be translated into a protein.

Restriction Enzyme

Enzymes that cut DNA at specific sequences.

Gel Electrophoresis

Technique used to separate DNA fragments by size through a gel matrix.

Gene Expression

The process by which information from a gene is used to synthesize a functional gene product.

Eukaryotic Gene Regulation

Mechanisms that control genes' expression in eukaryotic cells.

oncogenes

mutated genes that can cause cancer by causing cells to divide and grow uncontrollably

Taxonomy

The science of classifying organisms.

Linnaean System

Classification system based on hierarchical categories.

Natural Selection

Mechanism by which organisms better adapted to their environment tend to survive and reproduce.

Homology

Similarity in characteristics resulting from shared ancestry.

Homologous Structures

Anatomical features in different species that are similar due to common ancestry.

Vestigial Structures

Body parts that have lost their original function through evolution.

Gene Pool

The total collection of genes in a population at any one time.

Allele Frequency

The relative frequency of an allele at a genetic locus in a population.

Hardy-Weinberg Equation

p² + 2pq + q² = 1; used to calculate allele frequencies.

Microevolution

Small-scale evolutionary changes within a population.

Evolutionary Fitness

The reproductive success of an organism relative to other organisms.

Reproductive Success

The passing of genes to the next generation.

Sexual Selection

Natural selection arising through preference by one sex for certain characteristics in individuals of the other sex.

Sexual Dimorphism

Differences in physical characteristics between males and females of a species.

Stabilizing Selection

Natural selection that favors average individuals in a population.

Common Ancestry

The concept that different species share a common ancestor.

Lamarck's Evolution

Proposed that organism traits evolve based on their use or disuse.

Charles Darwin

He observed variation, competition, and adaptations in species during his voyage.

Evidence Supporting Darwin's Theory

Fossil records, anatomical similarities, and molecular biology.

Fossils

Preserved remains or traces of ancient organisms.

Evolutionary Tree

A diagram showing the evolutionary relationships among various biological species.

Population

A group of individuals of the same species living in the same area.

Mechanisms of Evolution

Natural selection, mutations, gene flow, and genetic drift.

Genetic Variation

Diversity in gene frequencies among a population.

Gene Pool Analysis

Method used to determine genetic diversity and evolution in a population.

Allele Frequencies

Proportion of a specific allele among all alleles for a specific gene.

Microevolution Mechanisms

Mutation, gene flow, genetic drift, and natural selection.

Genetic Drift

Random changes in allele frequencies in a population.

Ways Genetic Drift Occurs

Bottleneck effect and founder effect.

Gene Flow

Transfer of genetic variation from one population to another.

Sexual Selection Evolution

Process of evolution driven by mate choice and competition.

Outcomes of Natural Selection

Directional selection, stabilizing selection, and disruptive selection.

Homology vs. Analogy

Homology indicates a common ancestor; analogy refers to similar traits due to convergent evolution.

Convergent Evolution

Evolution of similar traits in distantly related species due to adaptation to similar environments.

Reproductive Barrier

Any factor that prevents two species from producing viable offspring.

Allopatric Speciation

Speciation occurring due to geographical isolation.

Sympatric Speciation

Speciation that occurs without geographical separation.

Exaptations

Traits that evolved for one purpose but were co-opted for another.

Analogous Structures

Body parts in different species that have similar functions but evolved independently.