Unit 3, List 2 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
one of the two identical halves of a chromosome that has been replicated in preparation for cell division
chromosome
threadlike structures made of protein and a single molecule of DNA that serve to carry the genomic information from cell to cell
codon
A codon is a trinucleotide sequence of DNA or RNA that corresponds to a specific amino acid.
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
the removal or obliteration of written or printed matter, especially by drawing a line through it.
diploid
(of a cell or nucleus) containing two complete sets of chromosomes, one from each parent.
DNA
the molecule that carries genetic information for the development and functioning of an organism
fertilization
a complex multi-step process that is complete in 24 hours.
frameshift
a genetic mutation caused by a deletion or insertion in a DNA sequence that shifts the way the sequence is read
gamete
a mature haploid male or female germ cell which is able to unite with another of the opposite sex in sexual reproduction to form a zygote.
gene
(in informal use) a unit of heredity which is transferred from a parent to offspring and is held to determine some characteristic of the offspring.
gene mutation
a change in one or more genes
genetic code
Genetic code refers to the instructions contained in a gene that tell a cell how to make a specific protein.
genetic variation
Without genetic variation, some key mechanisms of evolutionary change like natural selection and genetic drift cannot operate.
haploid
Haploid refers to the presence of a single set of chromosomes in an organism’s cells
homologous chromosome
made up of chromosome pairs of approximately the same length, centromere position, and staining pattern, for genes with the same corresponding loci
independent assortment
describes how different genes independently separate from one another when reproductive cells develop
insertion
the action of inserting something.
meiosis
a type of cell division in sexually reproducing organisms that reduces the number of chromosomes in gametes
meiosis I
the number of cells is doubled but the number of chromosomes is not
meiosis II
the second division in meiosis in which chromatids of each chromosome are segregated equally into daughter cells
monosomy
the condition in which only one chromosome from a pair is present in cells rather than the two copies usually found in diploid cells
mutagen
Anything that causes a mutation (a change in the DNA of a cell)
mutation
Any change in the DNA sequence of a cell.
nondisjunction
a pair of homologous chromosomes has failed to separate or segregate at anaphase so that both chromosomes of the pair pass to the same daughter cell
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
point mutation
occurs in a genome when a single base pair is added, deleted or changed
replication
the action of copying or reproducing something.
sexual reproduction
the production of new organisms by the combination of genetic information of two individuals of different sexes
somatic cell
cells in the body other than sperm and egg cells
substitution
the action of replacing someone or something with another person or thing.
trisomy
a chromosomal condition characterised by an additional chromosome
trait
a distinguishing quality or characteristic, typically one belonging to a person.
