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
monosomy
the absence of one member of a pair of chromosomes
mutagen
a chemical or physical agent capable of inducing changes in DNA called mutations
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 young creation of living organisms, produced either by sexual or asexual reproduction
parent cell
A cell that is the source of other cells, as a cell that divides to produce two or more daughter cells, or a stem cell that is a progenitor of other cells or is the first in a line of developing cells
replication
the process by which the genome’s DNA is copied in cells
point mutation
A genetic alteration caused by the substitution of a single nucleotide for another nucleotide
sexual reproduction
the production of new organisms by the combination of genetic information of two individuals of different sexes
somatic cell
the cells in the body other than sperm and egg 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
