Genetic Control of Cell Function & Inheritance

A complete set of vocabulary flashcards covering central molecular biology concepts, chromosome structure, cell division, inheritance patterns, and recombinant DNA technology.

Gene

A segment of DNA that contains instructions for making functional products, especially proteins.

Genome

The complete genetic information of an organism.

Proteome

The complete set of proteins encoded by the genome.

Proteomics

The study of the proteome and the molecular/biochemical events involving proteins.

Nucleotide

The structural unit of DNA consisting of a phosphate group, a deoxyribose sugar, and one nitrogenous base.

Purine

A class of nitrogenous base that includes Adenine (A) and Guanine (G).

Pyrimidine

A class of nitrogenous base that includes Thymine (T) and Cytosine (C) in DNA.

Semiconservative Replication

A mode of DNA replication where every new DNA molecule contains one original strand and one newly synthesized strand.

Chromatin

A complex formed when DNA wraps around histone proteins, compacting DNA so it can fit inside the nucleus.

Chromatin Remodeling

A process that alters how tightly DNA is packaged to help control whether genes can be accessed.

Mutation

A permanent change in DNA sequence that may involve substitution, loss, addition, or rearrangement of bases.

Somatic-Cell Mutation

A mutation in body cells that affects the individual but is not normally inherited by offspring.

Germ-Cell Mutation

A mutation in reproductive cells that can be passed on to offspring.

Polymorphism

A common DNA variation present in a population.

Messenger RNA (mRNA)

A type of RNA that carries the genetic message from DNA, using codons to specify amino acids.

Ribosomal RNA (rRNA)

A type of RNA that forms a major part of ribosomes, the site of protein synthesis.

Transfer RNA (tRNA)

A type of RNA that carries a specific amino acid to the ribosome and matches its anticodon to the mRNA codon.

Codon

A sequence of $3$ bases on mRNA that specifies an amino acid or a start/stop signal.

Anticodon

A complementary $3$-base sequence on tRNA that recognizes a specific mRNA codon.

Transcription

The process occurring in the nucleus where DNA information is copied into RNA.

Promoter

A DNA region where the transcription machinery binds to begin transcription.

Exons

Retained sequences in mature mRNA that contribute to the protein-coding message.

Introns

Intervening sequences in pre-mRNA that are removed during RNA splicing.

Translation

The process occurring in the cytoplasm where mRNA codons are converted into an amino acid or protein sequence.

Molecular Chaperones

Proteins that assist in proper protein folding and help prevent misfolding.

Gene Expression

The degree to which a gene or group of genes is active.

Homologous Chromosomes

Chromosome pairs containing similar genes at corresponding locations, with one homolog inherited from each parent.

Karyotype

An organized photographic display of a person's chromosomes, usually arranged in homologous pairs.

Cytogenetics

The study of chromosome structure and number.

Centromere

The site where two chromatids are joined together in a chromosome.

Telomeres

Specialized DNA structures at chromosome ends that protect chromosome integrity and allow ends to be replicated.

Locus

The specific physical location of a gene on a chromosome.

Mitosis

Cell division in somatic cells involving $1$ division to yield $2$ daughter cells, each with $46$ chromosomes ($23$ pairs).

Meiosis

Cell division in the germ-cell line involving $2$ divisions to produce $4$ gametes, each with $23$ chromosomes.

Crossing-Over

The exchange of DNA segments between homologous autosomes during meiosis I, creating new gene combinations.

Spermatogenesis

The meiotic process in males that generally produces four viable sperm cells.

Oogenesis

The meiotic process in females that produces one mature ovum plus polar bodies.

Genotype

A person's genetic makeup or allele combination.

Phenotype

The observable or measurable expression of a genotype.

Allele

An alternative form of a gene located at a specific locus.

Homozygous

Having two identical alleles at a specific locus, such as $AA$ or $aa$.

Heterozygous

Having two different alleles at a specific locus, such as $Aa$.

Dominant Allele

An allele that is expressed in the phenotype when one or two copies are present.

Recessive Allele

An allele that is usually expressed in the phenotype only when two copies are present.

Carrier

An individual heterozygous for a recessive disease allele who carries the allele without displaying the recessive phenotype.

Polygenic Inheritance

An inheritance pattern involving multiple genes, where each gene contributes to the phenotypic trait.

Multifactorial Inheritance

An inheritance pattern involving multiple genes along with environmental influences.

Epistasis

A genetic phenomenon where one gene masks or modifies the phenotypic effect of another gene.

Genetic Imprinting

A phenomenon where gene expression depends on whether the allele was inherited from the mother or the father.

Uniparental Disomy

A condition where both copies of a chromosome are inherited from a single parent.

Pedigree

A diagram of a family's history of an inherited trait used to trace inheritance patterns across generations.

Single Nucleotide Polymorphism (SNP)

A genetic variation occurring at a single DNA base.

Haplotype

A group of closely linked DNA variants or SNPs on one chromosome that tend to be inherited together.

Recombinant DNA

DNA molecules created by combining DNA sequences that do not normally occur together in nature.

Restriction Enzymes

Enzymes that cut DNA molecules at specific recognition sequences.

DNA Ligase

An enzyme that joins separated DNA fragments together.

RNA Interference (RNAi)

A natural gene-silencing mechanism where small RNA molecules suppress gene expression and prevent protein production.