Topic 8- Key Terms Flashcards
Define A Gene?
A section of DNA located at a particular (fixed site) called the locus.
Define Intron
The non-coding, intervening sequence of DNA within a gene
Define Exon
Regions coding for proteins and interrupted by the unused sequences called introns
Define Degenerate
The genetic code is degenerate because there are many instances in which different codons code for the same amino acids.
Define Chromosomes
Threadlike structure made of proteins and DNA by which hereditary information is physically passed from one generation to the next.
Define Centromere
It is the point of attachment of the kinetochore, a structure to which the microtubules of the mitotic spindle become anchored
Define Homologous Chromosomes
They are pairs of chromosomes, one maternal set, and one paternal set. They contain the same genes in the same loci but are not necessarily identical
Define Meiosis
Type of nuclear division in which the number of chromosomes is halved.
Define Codon
A sequence of three adjacent nucleotides in mRNA that codes or one amino acid
Define Genome
An organisms complete set of DNA
Define Proteome
Refers to the complete set of proteins expressed by a genome in an organism
Define mRNA
It is made by copying a strand of DNA called the template strand.
A sequence of three nucleotides that correspond with a specific amino acid or start/stop signal during translation
Define tRNA
Small RNA molecules that carry amino acids to the ribosomes for polymerization into polypeptides
Define Transcription
The process by which complimentary mRNA copy is made of the specific regions of the DNA molecule which codes for a polypeptide
Define Translation
The process by which ribosomes in the cytoplasm or endoplasmic reticulum synthesize proteins after transcription
Define Splicing
The process by which introns are removed from pre-mRNA to produce mature mRNA that only contains exons
Define Pre-mRNA
An mRNA molecule that still contains both introns and exons
Define Polypeptide
Formation of a polypeptide involves the formation of a peptide bond between amino acids
Define Allele
Different forms of a gene
Define Anti-Codon
A sequence of three adjacent nucleotides on a molecule of tRNA that is complimentary to a particular codon on mRNA.
Define Template Strand
It refers to the strand used by DNA polymerase or RNA polymerase during DNA replicated
Define Peptide Bond
A chemical bond formed between two amino acids during condensation
Define Histone Proteins
Highly alkaline proteins found in eukaryotic cell nuclei that package and order nucleosomes. DNA coils around them.
Define Chromatid
One of the two strands of a chromosome that are joined together by a single centromere prior to cell division
Define Diploid
A term applied to cells in which the nucleus contains two sets of chromosomes.
Define Haploid
The number of chromosomes in a single set is called the haploid number
Define Locus
In genetics, it is a fixed position on a chromosome
