Unit 3 List 2 DNA & Heredity KYS Flashcards
allele
One of two or more versions of a genetic sequence at a particular region on a chromosome
centromere
structure in a chromosome that holds together the two chromatids
chromatid
one of the two identical halves of a chromosome that has been replicated in preparation for cell division
chromosome
A structure found inside the nucleus of a cell; made up of proteins and DNA
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 mutation that involves the loss of one or more nucleotides from 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
a molecule that carries genetic information for 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
An insertion or deletion involving a number of base pairs that is not a multiple of three, which consequently disrupts the triplet reading frame of 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 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
a measure of the genetic differences that exist within a population
haploid
the presence of a single set of chromosomes in an organism’s cells
homologous chromosome
pairs of chromosomes in a diploid organism that have similar genes, although not necessarily identical
insertion
A type of genetic change that involves the addition of a segment of DNA
independent assortment
the alleles of two (or more) different genes get sorted into gametes independently of one another
meiosis
a process where a single cell divides twice to produce four cells containing half the original amount of genetic information
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
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
point mutation
change within a gene in which one base pair in the DNA sequence is altered
replication
the process by which the genome’s DNA is copied in cells
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
