Honors Biology Final Exam Review 2025 Summary

Gametes and somatic cells

Cells involved in sexual reproduction (sperm and egg) and body cells

Haploid vs. diploid cells

Having one set of chromosomes (n) vs. having two sets of chromosomes (2n)

Independent assortment and segregation

Mendel's laws: alleles of different genes assort independently during gamete formation; allele pairs separate during gamete formation and randomly unite at fertilization

Synapsis and crossing over

Pairing of homologous chromosomes during prophase I of meiosis, allowing for crossing over

Homologous chromosomes and sister chromatids

Pairs of chromosomes with the same genes, one from each parent; identical copies of a single chromosome formed after DNA replication

Karyotype

Organized profile of an organism's chromosomes

Stages of meiosis

Prophase I, Metaphase I, Anaphase I, Telophase I, Prophase II, Metaphase II, Anaphase II, Telophase II

Mitosis vs. meiosis

Cell division resulting in two identical daughter cells vs. cell division resulting in four genetically different daughter cells with half the number of chromosomes

DNA nucleotide structure

Monomer of DNA consisting of a sugar, phosphate group, and nitrogenous base

Antiparallel DNA strands

DNA strands run in opposite directions (3'-5' and 5'-3')

DNA Polymerase, DNA Helicase, DNA Ligase

Enzyme that adds complementary nucleotides to the template strand; enzyme that unwinds DNA; enzyme that joins DNA fragments

Leading and lagging strands, Okazaki fragments

Strand synthesized continuously vs. strand synthesized in fragments (Okazaki fragments)

Semi-conservative replication

Each new DNA molecule consists of one original strand and one new strand

Gene expression

Process by which the information encoded in DNA is used to synthesize functional gene products

RNA vs. DNA

Single-stranded, ribose sugar, uracil base vs. double-stranded, deoxyribose sugar, thymine base

mRNA, tRNA, rRNA

Types of RNA: messenger, transfer, ribosomal

Transcription and translation

DNA to RNA vs. RNA to protein

RNA editing: Spliceosome, introns, exons

Removal of introns and joining of exons; complex that splices RNA; noncoding regions; coding regions

Codons and anticodons

Three-nucleotide sequence on mRNA that codes for an amino acid; three-nucleotide sequence on tRNA that is complementary to the codon

Central dogma of biology

DNA -> RNA -> Protein

Chromosomal mutations: Deletion, inversion, translocation, duplication

Changes in chromosome structure: deletion, inversion, translocation, duplication

Gene mutations: Point, substitution, insertion, deletion, frameshift

Changes in a single gene: point, substitution, insertion, deletion, frameshift

Operons and lac operons

Set of genes that are transcribed together; operon that codes for lactose-digesting enzymes

Recombinant DNA

DNA molecules that are artificially created

DNA fingerprinting

Identifying individuals based on their DNA

Restriction enzymes

Enzymes that cut DNA at specific sequences

PCR and CRISPR

Techniques used to amplify DNA; genome editing tool

DNA sequence to mRNA and amino acid sequences

Process of converting a DNA sequence into an mRNA sequence and then into an amino acid sequence

Heredity and genetics

Study of inheritance

Alleles: dominant and recessive

Different versions of a gene: dominant (expressed) and recessive (masked)

Genotype and phenotype

Genetic makeup vs. physical characteristics

Homozygous and heterozygous

Having two identical alleles vs. having two different alleles

Incomplete dominance and codominance

Neither allele is fully dominant (blending) vs. both alleles are fully expressed

Sex-linked traits and autosomal traits

Traits located on sex chromosomes vs. traits located on autosomes (non-sex chromosomes)

Haploid and diploid

Having one set of chromosomes (n) vs. having two sets of chromosomes (2n)

Nondisjunction

Failure of chromosomes to separate properly during meiosis

Genetic disorders: Hemophilia, Down syndrome, Sickle-cell anemia, Colorblindness, Huntington’s disease, polydactyly

Examples of genetic disorders: Hemophilia, Down syndrome, Sickle-cell anemia, Colorblindness, Huntington’s disease, polydactyly

Blood type genotypes, antigens, and antibodies

Genotypes for blood types A, B, AB, and O; molecules on the surface of red blood cells; proteins that recognize and bind to foreign antigens

Monohybrid crosses

Cross involving one trait

Punnett squares for blood types

Diagrams used to predict the genotypes and phenotypes of offspring

Pedigree analysis

Diagram used to trace the inheritance of a trait through a family

Natural selection, fitness, adaptation, and competition

Process by which organisms better adapted to their environment tend to survive and reproduce; ability to survive and reproduce; trait that helps an organism survive and reproduce; struggle between organisms for limited resources

Evidence for evolution

Fossil record, comparative anatomy, biogeography, molecular biology

Homologous, analogous, and vestigial structures

Structures with similar structure but different function; structures with different structure but similar function; remnants of structures that had a function in an ancestor

Stabilizing, directional, and disruptive selection

Selection that favors intermediate phenotypes; selection that favors one extreme phenotype; selection that favors both extreme phenotypes

Genetic drift and speciation

Random changes in allele frequencies; process by which new species arise

Reproductive isolation: behavioral, temporal, geographic

Barriers that prevent different species from interbreeding: behavioral, temporal, geographic

Pre- vs. post-zygotic reproductive barriers

Barriers that occur before the formation of a zygote vs. barriers that occur after the formation of a zygote

Hardy-Weinberg equilibrium and equations

Principle stating that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences and equations to calculate allele and genotype frequencies

Taxonomy and taxa

Science of classifying organisms; group of organisms

Order of taxa from broadest to most specific

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Three domains and six kingdoms

Bacteria, Archaea, Eukarya; Archaebacteria, Eubacteria, Protista, Fungi, Plantae, Animalia

Cladogram analysis

Diagram used to show evolutionary relationships among organisms

Viruses: lytic and lysogenic infections; viral diseases

Lytic: virus infects cell, replicates, and lyses the cell; Lysogenic: virus infects cell and integrates its DNA into the host cell's DNA; Viral diseases

Archaebacteria and bacteria; bacterial diseases

Prokaryotes without peptidoglycan in cell walls; prokaryotes with peptidoglycan in cell walls; bacterial diseases

Peptidoglycan, Gram-positive, Gram-negative bacteria

Layer in bacteria cell walls: Gram-positive (thick layer) and Gram-negative (thin layer)

Coccus, bacillus, spirillum bacteria

Spherical, rod-shaped, and spiral-shaped bacteria

Strepto- and staphylo- arrangements

Strepto-: chains of bacteria; Staphylo-: clusters of bacteria

Endospores

Dormant, tough, and non-reproductive structure produced by some bacteria

Conjugation

Transfer of genetic material between bacteria through direct contact

Vaccines and types of vaccines; vaccine boosters

Weakened or inactive form of a pathogen that stimulates an immune response; types: attenuated, inactivated, subunit, toxoid; dose that increases effectiveness of vaccine

Antibiotics

Drugs that kill or inhibit the growth of bacteria

How bacteria cause disease

Invasion, toxins, and immune response

Protists: pseudopodia, flagellate, ciliate, nonmotile; protist diseases

Protozoans: pseudopodia (false feet), flagellate (flagella), ciliate (cilia), nonmotile (nonmotile); protist diseases

Fungi: hyphae, chitin, fruiting body, decomposers; fungal diseases

Threadlike filaments, cell walls made of chitin, reproductive structure, break down dead organisms; fungal diseases

Plants: autotrophs, nonvascular, seedless vascular, gymnosperms, angiosperms

Organisms that make their own food, nonvascular (no vascular tissue), seedless vascular (vascular tissue, no seeds), gymnosperms (naked seeds), angiosperms (seeds in fruits)

Xylem and phloem

Vascular tissue that transports water and minerals; vascular tissue that transports sugars

Seeds and fruits

Embryo and nutrients enclosed in a protective coating; mature ovaries

Cell wall contrasts: fungi, plants, bacteria

Fungi (chitin), plants (cellulose), bacteria (peptidoglycan)

Fertilization, zygote, morula, blastula, gastrulation, blastopore

Fertilization (sperm + egg), zygote (fertilized egg), morula (solid ball of cells), blastula (hollow ball of cells), gastrulation (formation of germ layers), blastopore (opening that forms during gastrulation)

Protostomes and deuterostomes

Blastopore becomes mouth vs. blastopore becomes anus

Endoderm, mesoderm, ectoderm

Inner layer, middle layer, outer layer

Invertebrates and chordates (vertebrates)

Animals without a backbone vs. animals with a backbone

Endotherms and ectotherms

Animals that generate their own body heat vs. animals that rely on external sources of heat

Invertebrate phyla characteristics and examples: Porifera, Cnidaria, Platyhelminthes, Annelida, Arthropoda, Mollusca, Echinodermata

Examples: Porifera (sponges), Cnidaria (jellyfish), Platyhelminthes (flatworms), Annelida (segmented worms), Arthropoda (insects), Mollusca (snails), Echinodermata (starfish)

Vertebrate phyla examples: Agnatha, Chondrichthyes, Osteichthyes, Amphibia, Reptilia, Aves, Mammalia (marsupial, monotreme, placental)

Examples: Agnatha (jawless fish), Chondrichthyes (cartilaginous fish), Osteichthyes (bony fish), Amphibia (amphibians), Reptilia (reptiles), Aves (birds), Mammalia (mammals)