Unit 3 List 2 DNA & Heredity Flashcards
allele
1of 2 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
1 of the 2 identical halves of a chromosome that has been replicated in preparation for cell division.
chromosome
A combination of DNA and proteins in the cell nucleus that serve to carry the genomic information from cell to cell.
codon (chart)
A chart of all the codons and the amino acids they stand for.
crossing over
The exchange of DNA between paired homologous chromosomes that occurs during 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
Two complete sets of chromosomes in an organism’s cells.
DNA
The molecule that carries genetic information.
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.
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 in a gene that tell a cell how to make a protein.
genetic variation
The variation in the DNA sequence in each of our genomes.
haploid
The presence of a single set of chromosomes in an organism’s cells.
independent assortment
The alleles of 2 genes will segregate into daughter cells independent of one another.
homologous chromosome
Pairs of chromosomes originating from each parent.
insertion
A mutation that involves the addition of 1or more nucleotides to DNA.
meiosis
A type of cell division that reduces the number of chromosomes in the parent cell by half
meiosis I
The number of cells is doubled but the number of chromosomes is not.
meiosis II
The sister chromatids within the 2 daughter cells separate, forming 4 new haploid gametes.
monosomy
The absence of one member of a pair of chromosomes.
mutagen
A chemical or physical agent capable of inducing changes in DNA (mutations)
mutation
A change in the DNA sequence of an organism.
nondisjunction
The failure of the chromosomes to separate during cell division.
offspring
The product of the reproductive processes of an organism.
parent cell
A cell that is the source of other cells.
point mutation
A genetic alteration caused by the substitution of a single nucleotide.
replication
The process by which the genome’s DNA is copied in cells.
sexual reproduction
The production of new organisms by two individuals of different sexes.
somatic cell
Any type cell in the body other than cells involved in reproduction.
substitution
A type of mutation in which 1 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.
