Unit 3 List 2 DNA & Heredity PL Flashcards
Allele
One of two or more versions of a genetic sequence at a particular region on a chromosome. An individual inherits two alleles for each gene, one from each parent.
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. A chromosome is made up of proteins and DNA organized into genes.
Codon (chart)
A tool that we invented to help us understand codon recognition. By looking at the chart, we can see that each codon specifies one particular amino acid.
Crossing over
The exchange of DNA between paired homologous chromosomes (one from each parent) that occurs during the development of egg and sperm cells (meiosis).
Daughter cell
The cells that are formed after cell division.
Deletion
A type of genetic change that involves the absence of a segment of DNA.
Diploid
The presence of two complete sets of chromosomes in an organism’s cells, with each parent contributing a chromosome to each pair.
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 to a gene’s DNA sequence to produce something different.
Genetic code
A set of rules defining how the four-letter code of DNA is translated into the 20-letter code of amino acids.
Genetic variation
The presence of differences in sequences of genes between individual organisms of a species.
Haploid
A cell that contains a single set of chromosomes.
Homologous chromosome
Pairs of chromosomes in a diploid organism that have similar genes, although not necessarily identical.
Independent assortment
The alleles of two or more different genes get sorted into gametes independently of one another. This means that the allele a cell receives for one gene is not influences by an allele it receives for another gene.
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. (single cell divides twice and produces four daughter cells)
Meiosis I
The first stage of meiosis and produces two daughter cells with half the genetic information of the parent cell (duplicated).
Meiosis II
A mitotic division of each of the haploid cells produced in meiosis I.