Genomes definitions Flashcards
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Terms in this set (54)
Genomes
The complete set of an organism's DNA, including all of its genes and non-coding sequences, which varies in size and complexity between prokaryotes and eukaryotes.
Prokaryotic Genome
A compact, mostly uninterrupted sequence of DNA that codes for proteins, with minimal non-coding regions and regulatory sequences, showing a linear relationship between gene number and genome size.
Coding Sequences
Sequences of DNA that directly code for proteins, typically uninterrupted in prokaryotes, leading to a linear relationship between gene number and genome size.
DNA
A molecule that carries genetic instructions for the development, functioning, growth, and reproduction of all known organisms and many viruses.
Proteins
Molecules composed of amino acids that perform a vast array of functions within organisms, including catalyzing metabolic reactions, DNA replication, responding to stimuli, and transporting molecules.
Regulatory Sequences
DNA sequences that control gene expression by interacting with proteins to enhance or suppress transcription, crucial for proper gene function and regulation in both prokaryotic and eukaryotic genomes.
Eukaryotic Genome
The genetic material in eukaryotes, characterized by a large size, numerous genes, extensive non-coding DNA, repeated sequences, and complex regulatory elements.
Non Coding DNA
DNA sequences that do not code for proteins but play roles in regulation, structural integrity, and genome evolution, including introns, regulatory elements, and repetitive sequences.
ncDNA
Noncoding DNA (ncDNA) refers to sequences in the genome that do not code for proteins but can have regulatory, structural, or unknown functions, and make up a significant portion of eukaryotic genomes.
Repeated Sequences
Sequences of DNA that are repeated multiple times in the genome, often non-coding, and can vary in length and number between individuals, contributing to genetic diversity and evolution.
Protein Coding Genes
Segments of DNA that are transcribed into mRNA and translated into proteins, essential for cellular structure and function.
Genome Size
The total amount of DNA contained within one copy of a single genome, varying significantly between organisms and not directly proportional to the number of genes.
Linear Relationship
A relationship where an increase in one variable results in a proportional increase in another, forming a straight line when graphed.
Lateral Gene Transfer
The transfer of genes between organisms in a manner other than traditional reproduction, often seen in bacteria, allowing for rapid genetic variation and adaptation.
Horizontal Gene Transfer
The transfer of genetic material between organisms in a manner other than traditional reproduction, often seen in bacteria, allowing for rapid genetic diversity and evolution.
Transformation
The process by which bacteria uptake and integrate foreign DNA from their environment into their own genome, leading to genetic variation.
Tree Of Life
A diagram representing the evolutionary relationships among various species, showing how they diverged from common ancestors through genetic changes over time.
Phylogenetic Tree
A branching diagram showing evolutionary relationships among species based on similarities and differences in genetic or physical traits.
Synteny
Conserved arrangement of genes on chromosomes of different species, indicating shared ancestry and aiding in the study of evolutionary relationships.
Chromosome Duplication
The process where an entire chromosome or a segment of it is copied, resulting in an organism having extra genetic material, which can lead to evolutionary changes or genetic disorders.
Speciation
The evolutionary process where populations evolve to become distinct species, often through genetic divergence and reproductive isolation mechanisms.
Exon Shuffling
Rearrangement of exons within or between genes, leading to new proteins or functions, contributing to genetic diversity and evolution.
Novel Proteins
Proteins formed through exon shuffling or gene deletions, resulting in new structures or functions not previously present in the organism.
Deletions
The removal of DNA segments from a genome, potentially altering gene function and leading to new protein variants or functions.
Single Copy Genes
A unique gene present as a single copy in the genome, not part of a gene family or cluster, encoding a specific protein.
Tandem Clusters
Clusters of identical gene copies transcribed simultaneously to meet high demand, formed through gene duplication and unequal crossover.
Transcription
The process of copying a segment of DNA into RNA, particularly mRNA, which carries genetic information from the DNA to the ribosome for protein synthesis.
Receptors
Proteins on cell surfaces or within cells that bind to specific molecules, triggering a biological response.
Structural Proteins
Proteins that provide support and shape to cells and tissues, such as collagen in connective tissues and keratin in hair and nails.
Cell Junction Proteins
Proteins that form connections between cells, facilitating communication, adhesion, and maintaining tissue integrity. They include tight junctions, gap junctions, and desmosomes.
Chaperones
Proteins that assist in the proper folding and assembly of other proteins, preventing misfolding and aggregation, especially under stress conditions.
Gene Duplication
The process where an extra copy of a gene is added to the genome, often due to unequal crossover during meiosis, leading to genetic diversity and potential new functions.
Unequal Crossover
A misalignment of homologous chromosomes during meiosis that results in unequal exchange of genetic material, leading to duplications or deletions of gene segments.
Multi Gene Families
A set of similar genes formed through duplication, often encoding proteins with related functions, and can be located near each other or dispersed across the genome.
Gene Clusters
Clusters of similar genes located near each other on a chromosome, often arising from gene duplication, and typically involved in related functions or processes.
Hox Genes
Highly conserved gene family that determines the body plan of an embryo, defining different parts of the body and used by many organisms.
Constitutive Heterochromatin
Structural DNA that remains permanently condensed, typically found around centromeres and telomeres, and does not contain genes or participate in transcription.
Centromere
The region of a chromosome where sister chromatids are held together and where spindle fibers attach during cell division.
Telomeres
Protective DNA sequences at chromosome ends, preventing degradation and fusion, crucial for maintaining genomic stability during cell division.
Segmental Duplications
Duplicated DNA segments in a genome that are nearly identical and can lead to genetic variation and evolution through unequal crossing over.
Short Tandem Repeats
Short, repeated DNA sequences found in non-coding regions of the genome, varying in number between individuals, and often used in genetic profiling due to their high variability.
Microsatellites
Short, repeated DNA sequences that vary in number between individuals and are prone to unequal crossing over, leading to genetic diversity.
Single Nucleotide Polymorphism
A variation in a single DNA building block (nucleotide) at a specific position in the genome, which can affect gene function and contribute to individual differences in traits and disease susceptibility.
Transposable Element
A DNA sequence that can change its position within the genome, potentially creating mutations and altering the cell's genetic identity. They include transposons (DNA-based) and retrotransposons (RNA-based).
Transposons
Mobile genetic elements that move within a genome via a DNA intermediate, causing mutations and altering the cell's genetic identity.
Retrotransposons
Transposable elements that use an RNA intermediate to copy and insert themselves into new locations within the genome, often involving reverse transcriptase.
Long Interspersed Nuclear Element
A transposable element that uses an RNA intermediate and reverse transcriptase to insert itself back into the genome, contributing to genomic variation and evolution.
Line A
An transposable element that uses an RNA intermediate and reverse transcriptase to insert its sequence back into the genome.
Reverse Transcriptase
An enzyme that synthesizes DNA from an RNA template, crucial for retroviruses to integrate their genetic material into the host genome.
Pseudogenes
Inactive DNA sequences that were once functional genes but have lost their ability to code for proteins due to mutations.
MicroRNA
Small non-coding RNA molecules that regulate gene expression by binding to complementary mRNA sequences, leading to their degradation or inhibition of translation.
RNA Interference
A biological process where small RNA molecules inhibit gene expression by causing the degradation of specific mRNA molecules or hindering their translation into proteins.
Gene Expression
The process by which information from a gene is used to synthesize functional gene products, such as proteins, often involving transcription and translation.
Introns
Non-coding DNA segments within genes that are transcribed into RNA but removed during RNA splicing, not contributing to the final mRNA and thus not coding for proteins.