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 codon table can be used to translate a genetic code into a sequence of amino acids
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 process by which two gametes (reproductive cells having a single, haploid set of chromosomes) fuse to become a zygote, which develops into a new organism
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
the instructions contained in a gene that tell a cell how to make a specific protein
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
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
homologous chromosomes pair and then separate
meiosis II
a mitotic division of each of the haploid cells produced in meiosis I