Unit 3 List 2 DNA & Heredity Flashcards
Allele
One of two or more versions of a genetic sequence at a particular region on a chromosome.
Centromere
The region of the chromosome to which the spindle fiber is attached during cell division.
Chromatid
One of the two identical halves of a chromosome that has been replicated in preparation for cell division.
Chromosome
A structure found inside the nucleus of a cell.
Codon (chart)
Shows all of the possible three letter combinations of mRNA nucleotides, and for which amino acid each combination codes for.
Crossing over
The exchange of DNA between paired homologous chromosomes that occurs during the development of egg and sperm cells.
Daughter cell
Cells that are the result of a single dividing parent cell.
Deletion
A type of genetic change that involves the absence of a segment of DNA.
Diploid
A cell that contain two copies of each chromosome.
DNA
The molecule that carries genetic information for the development and functioning of an organism.
Fertilization
The union of two gametes.
Frameshift
A genetic mutation caused by a deletion or insertion in a DNA sequence that shifts the way the sequence is read.
Gamete
A reproductive cell of an animal or plant.
Gene
The basic unit of heredity passed from parent to child.
Gene mutation
A change in one or more genes.
Genetic code
The instructions contained in a gene that tell a cell how to make a specific protein.
Genetic variation
The difference in DNA sequences between individuals within a population.
Haploid
A cell that contains a single set of chromosomes.
Homologous chromosome
Matched pairs containing the same genes in identical locations along their lengths.
Independent assortment
The alleles of two (or more) different genes get sorted into gametes independently of one another.
Insertion
A type of mutation that involves the addition of one or more nucleotides into a segment of DNA.
Meiosis
A type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells.
Meiosis I
The first meiotic division.
Meiosis II
The second division in meiosis in which chromatids of each chromosome are segregated equally into daughter cells.
Monosomy
The condition in which only one chromosome from a pair is present in cells rather than the two copies usually found in diploid cells.
Mutagen
Any physical or chemical substance that can change the genetic material of an organism, thereby causing a mutation.
Mutation
Any change in the DNA sequence of a cell.
Nondisjunction
The failure of the chromosomes to separate, which produces daughter cells with abnormal numbers of chromosomes.
Offspring
The product of the reproductive processes of a person, animal, or plant.
Parent cell
The cell that divides to give rise to two daughter cells.
Point mutation
A genetic alteration caused by the substitution of a single nucleotide for another nucleotide.
Replication
The process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules.
Sexual reproduction
The production of new organisms by the combination of genetic information of two individuals of different sexes.
Somatic cell
Any cell of a living organism other than the reproductive cells.
Substitution
A type of mutation in which one nucleotide is replaced by a different nucleotide.
Trisomy
The presence of an extra chromosome in some or all of the body’s cells.
Trait
A specific characteristic of an individual.
