Genetics Grade 11 Vocabulary Flashcards
sites on a tetrad where chromatids separate and reunite
chiasmata (singular: chiasma)
period of genetic information duplication before mitosis
S (synthesis) phase
possession of more than two sets of chromosomes
polyploidy
substance or agent that causes a mutation
mutagen
technique that uses sound waves to produce an image of the fetus in the uterus
ultrasound
specialized reproductive cell (e.g. egg or sperm) that unites with another of a different sex to produce a zygote through sexual reproduction
gamete
cells that produce sperm in the testes
spermatogonia (singular: spermatogonium)
mating of two individuals both heterozygous for a particular trait
monohybrid (cross)
removal and analysis of cells from a membrane that surrounds the fetus in the uterus
chorionic villus sampling (CVS)
structure in the nucleus of a eukaryotic cell that carries genes, formed when chromatin condenses
chromosome
extraction of amniotic fluid from the uterus to diagnose genetic defects in the fetus
amniocentesis
thread-like structure made up of DNA and proteins in the nucleus of a eukaryotic cell
chromatin
environmental agent that causes a congenital defect
teratogen
reversed order of attachment of a chromosome fragment to a homologous chromosome during crossing over
inversion
describes an organism bred to express a particular form of a trait
purebred
one of two genetically identical cells produced when a cell divides by mitosis
daughter cell
describes the independent segregation of genes for different traits when a gamete forms
law of independent assortment
describes an organism with two identical alleles of a certain gene
homozygous
the third phase of mitosis; paired chromatids separate
anaphase
interrupted range of expression of a trait controlled by only one gene pair
discontinuous distribution
blood test used in pregnant women to identify abnormal hormone levels seen in pregnancies with an increased chance of certain genetic defects
Maternal Serum Screening
representation of the transmission patterns of a heritable trait across generations of parents and offspring
pedigree
attachment of a chromosome fragment to a homolog that is already complete during crossing over
duplication
complete expression of two different alleles of a gene in a heterozygote
co-dominance
physical characteristics of an organism
phenotype
the fusion of male and female gametes to form a zygote
fertilization
describes the separation of the members of an allele pair when a gamete forms
law of segregation
nucleic acid, encoded with instructions to produce proteins, that stores and transmits genetic information from one generation to the next
deoxyribonucleic acid (DNA)
use of a gene product or manipulation of abnormal DNA to treat a genetic condition
gene (or genetic) therapy
human selection of certain individual organisms with desirable traits to breed and produce offspring with those traits
selective breeding
describes the production of two identical DNA molecules through replication, each molecule containing one of the two strands of the original molecule
semiconservative
genetically identical copy of an organism
clone
failure of chromosomes to separate or move apart during meiosis
nondisjunction
offspring of two F1 generation individuals in a study of inhertiance
F2 (second filial) generation
DNA molecule formed when a biologist splices and combines portions of DNA from two different sources
recombinant DNA
parent individuals that produce offspring in a study of inheritance
P generation
chromosome produced by the exchange of chromosome segments between homologous chromosomes during crossing-over
recombinant
membrane that forms in a dividing plant cell and develops into a cell wall that separates the daughter cells
cell plate
specific location of a gene on a chromosome
locus (plural: loci)
paired set of homologous chromosomes, each chromosome with two chromatids
tetrad
attachment of a chromosome fragment to a nonhomologous chromosome during crossing over
translocation
insertion of one piece of genetic material into another
gene splicing
modification of a structure or function in an individual that allows the organism to adjust to a new environment or condition
adaptation
one of a pair of chromosomes (one from the mother, one from the father) that each carry genes for the same trait at the same location on the chromosome
homologous chromosome (homolog)
international scientific research project with the goal of determining the sequence of nucleotide base pairs that make up human DNA, and of identifying and mapping all of the genes of the human genome from both a physical and a functional standpoint
Human Genome Project
possession of an extra copy of a particular chromosome
polysomy
genes on the same chromosome that fail to sort independently of one another and are inherited together
linkage group
range of expression of a multifactorial trait
continuous distribution
segment of DNA that carries the code for a specific protein
gene
a diagram that is used to predict the genotypes of a particular cross or breeding experiment
Punnett square
mutation present at birth
congenital defect
centriole surrounded by tiny protein fibres during mitosis
aster
representation of the location and order of genes on a chromosome
gene map
division of a cell’s cytoplasm into two distinct cells
cytokinesis
when there are more than two possible alleles for a given gene
multiple allelism
production of a new organism by a single parent without the participation of eggs and sperm
asexual reproduction
incomplete expression of two different alleles of a gene in a heterozygote (results in intermediate expression)
incomplete dominance
first phase of mitosis in which the chromatin condenses and duplicated chromosomes become visible (and the mitotic spindle forms)
prophase
period of the cell cycle between cell divisions
interphase
describes an organism with two different alleles for a certain gene
heterozygous
bacterial enzyme that cuts up foreign DNA; used in genetic engineering to create recombinant DNA
restriction enzyme
human genetic disease caused by the failure of blood to form clots
hemophilia
describes the form of a trait that is only expressed in the homozygous condition
recessive
number of chromosome in a cell that contains a single set of chromosomes (present in gametes)
haploid number (n)
chromosome not involved in determining the sex of an organism
autosomes
period of cell growth before mitosis
G1 (first gap) phase
an individual who is heterozygous for two traits (e.g. AaBb)
dihybrid (cross)
expression of one allele of a gene over the other
dominance
in cell division, division of a nucleus into two genetically identical nuclei; divided into five stages
mitosis
condition that results from the possession of an extra copy of chromosome 21 (also called trisomy 21)
Down syndrome
possession of only one of a homologous pair of chromosomes in an otherwise diploid cell
monosomy
number of chromosomes in a body cell of an organism
diploid number (2n)
union point of two chromatids that join to form a chromosome pair
centromere
transmission of hereditary information from a parent cell to the daughter cells in mitosis or from generation to generation in sexual reproduction
genetic continuity
the production of new living organisms by combining genetic information from two individuals of different types
sexual reproduction
cell dividion process that involves two divisions with only one duplication of chromosomes (results in haploid gametes)
meiosis
all the alleles of a specific trait in a population
gene pool
genetic make up of an organism
genotype
describes a trait whose expression is controlled by genes found at many loci (expression of this trait may also be influenced by other contributing factors)
multifactorial
chromosome that lacks genetic information due to the failure of a chromosome fragment to attach to its homologous chromosome during crossing over
deletion
cells that produce eggs in the ovary
oogonia (singular: oogonium)
fourth phase of mitosis in which the nuclear envelope reforms, the chromosomes uncoil, and the nucleoii reappear
telophase
change in the expression of many genes caused by a defect in one gene
pleiotropy
one form of a gene for a specific trait
allele
transmital of genes on the same chromosome that fail to sort independently of one another and are inherited together
gene linkage
small ring of DNA in a bacterium (often used in genetic recombination)
plasmid
pairing of duplicated homologous chromosomes during meiosis (crossing over may occur at this stage)
synapsis
duplication of DNA before mitosis or meiosis
replication
exchange of chromosome segments between homologous chromosomes during meiosis
genetic recombination or crossing over
the science of heredity
genetics
period of cell preparation for division before mitosis
G2 (second gap) phase
offspring of two P generation individuals in a study of inheritance
F1 (first filial) generation
second phase of mitosis; chromosomes line up across the middle of the cell
metaphase
allele that is expressed in a heterozygous individual
dominant
possession of an abnormal number of chromosomes
aneuploidy
first division of meiosis, resulting in the reduction by half of the number of chromosomes in a cell
reduction division
union of gametes that is the first cell of a new organism
zygote
each of the two identical chromosome strands in a replicated chromosome attached by their shared centromere
chromatid
number and form of chromosomes in a cell
karyotype
describes the production of a DNA molecule without the inclusion of strands from the original molecule
conservative