Biology Final Exam Study Guide: DNA, Heredity, and Evolution

A comprehensive vocabulary review covering DNA structure, transcription, translation, mutations, inheritance patterns, cell division (mitosis/meiosis), and evolutionary mechanisms based on the study guide transcript.

DNA Nucleotide

The monomer (building block) of DNA consisting of three parts: a sugar, a phosphate group, and a nitrogenous base.

Gene

A segment of DNA that codes for a specific protein and determines a trait.

Allele

A variation or different form of a specific gene.

Chargaff’s rules

The rules of base pair matching in DNA where specific nitrogen bases bond together (e.g., Adenine with Thymine, Cytosine with Guanine).

Transcription

The process that takes place in the nucleus where a template strand of DNA is used to create mRNA.

Translation

The process where mRNA is used by a ribosome and tRNA to assemble amino acids into a protein.

mRNA

The molecule that brings the genetic message from the DNA in the nucleus to the ribosome in the cytoplasm.

tRNA

The molecule involved in translation that carries specific amino acids to the ribosome.

Substitution

A type of mutation where one nucleotide is replaced by another.

Frameshift Mutation

A mutation caused by an insertion or deletion that changes the reading frame of the genetic sequence, affecting all subsequent amino acids.

Silent Mutation

A mutation that does not result in a change to the amino acid sequence of the protein.

Missense Mutation

A mutation that results in the substitution of one amino acid for another in the protein.

Nonsense Mutation

A mutation that changes an amino acid codon into a premature stop codon, usually resulting in a nonfunctional protein.

Chromosome

A structure organized from DNA and proteins that carries genetic information.

Gamete

A reproductive cell (sperm/egg) that is haploid and used in sexual reproduction, differing from normal body cells.

Meiosis

A type of cell division that produces four unique haploid cells, increasing genetic variation in offspring.

Mitosis

A type of cell division that produces two identical diploid cells for growth and repair.

Asexual Reproduction

Reproduction involving a single parent that results in offspring that are genetically identical to the parent.

Haploid

A cell containing a single set of chromosomes, denoted as $n$.

Diploid

A cell containing two complete sets of chromosomes, one from each parent, denoted as $2n$.

Codominance

A pattern of inheritance where both alleles are expressed equally in the phenotype, such as speckled chickens.

Incomplete Dominance

A pattern of inheritance where the heterozygous phenotype is a blend of the two homozygous phenotypes.

Sex-linked traits

Traits located on the sex chromosomes, such as color blindness which is located on the $X$ chromosome.

Variation

The differences that exist between individuals of the same species in a population.

Adaptation

A trait that helps an organism survive and reproduce in its environment.

Natural Selection

The process where the selective force is the environment, allowing organisms with advantageous traits to survive and reproduce.

Artificial Selection

The process where humans act as the selecting force to breed organisms for specific desired traits.

Sexual Selection

A form of selection where the selecting force is the mate's preference for certain traits.

Genetic Drift

A change in the frequency of a trait in a population due to random chance events.

Bottleneck Effect

A sharp reduction in population size that leads to a loss of genetic variation.

Lamarckian language

Evolutionary descriptions involving the inheritance of acquired characteristics or the idea that individuals evolve based on need or use/disuse.