Unit 3 List 2 DNA & Heredity Flashcards
allele
one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.
centromere
the region of a chromosome to which the microtubules of the spindle attach, via the kinetochore, during cell division.
chromatid
each of the two threadlike strands into which a chromosome divides longitudinally during cell division. Each contains a double helix of DNA.
Chromosome
a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
codon (chart)
a chart of all the codons and the amino acids they stand for
crossing over
a cellular process that happens during meiosis when chromosomes of the same type are lined up
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. During fertilization, sperm and egg fuse to form a diploid zygote to initiate prenatal development
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. It creates a permanent change to that gene’s DNA sequence
genetic code
a set of three-letter combinations of nucleotides called codons, each of which corresponds to a specific amino acid or stop signal
genetic variation
a term used to describe the variation in the DNA sequence in each of our genomes
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
a genetic principle that states that the alleles of two genes will segregate into daughter cells independent 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
a specialized type of cell division that reduces the chromosome number by half, resulting in the production of four genetically distinct haploid cells from an original diploid cell
meiosis II
a mitotic division of each of the haploid cells produced in meiosis I
