Topic 4: Mendelian Genetics Flashcards

Terms Definitions
Life Cycle
The generation-to-generation sequence of stages in the reproductive history of an organism.
Somatic Cell
Any cell in a multi-cellular organism except a sperm or egg.
Clone
A lineage of genetically identical cells
Karyotype
A display of the chromosome pairs of a cell arranged by size and shape.
Homologous Chromosomes
A pair of chromosomes of the came length, centromere position, and staining pattern that possesses genes for the same characters at corresponding loci. One is inherited from the organism's father, the other from the mother.
Sex Chromosomes
Chromosomes responsible for determining the sex of an individual.
Autosomes
Chromosomes that are not directly involved in determining sex.
Diploid Cell
A cell containing two sets of chromosomes.
Haploid Cell
A cell containing only one set of chromosomes.
Fertilization
The union of haploid gametes to produce a diploid zygote.
Zygote
the diploid product of the union of haploid gametes during fertilization.
Alternation of Generations
It is a life cycle in which there is both a multicellular diploid form and multicellular haploid form and it is characteristic of some plants and algae.
Character
A heritable feature that varies among individuals.
Trait
Each variant for a character.
True Breeding
Referring to plants that produce offspring of the same variety when they self-pollinate.
Hybridization
The mating of two true-breeding varieties.
P generation
The parent individuals from which offspring are derived.
F1 generation
The first filial, or hybrid, offspring in a series of genetic crosses.
F2 generation
Offspring resulting from interbreeding of the hybrid F1 generation.
Alleles
Any of the alternative versions of a gene that produce distinguishable phenotypic affects.
Punnett Square
A device for predicting the allele combinations of offspring from a cross between two individuals with known genotypes.
Homozygous
An organism that has a pair of identical alleles.
Heterozygous
An organism that has two different alleles.
Phenotype
An organism's traits; the expression of the alleles.
Genotype
An organism's genetic makeup; its allele combination.
Monohybrid Cross
Breeding a white and purple flowers
Dihybrid Cross
Breeding a plant with yellow wrinkled peas with one that has green round peas.
Law of Independent Assortment
Mendels' second law, stating that each pair of alleles segregates or assorts, independently of each during gamete formation; this applies when genes for two characters are located on different pairs of homologous chromosomes.
Rules of Multiplication
States that in order to determine the probability that two independent events will occur together, one must multiply the probability of one event by the probability of the other event.
Rules of Addition
States that the probability that any one of two or more mutually exclusive events will occur is calculated by adding together their individual probabilities.
Codominance
Both proteins are being expressed.
Incomplete Dominance
A mix of the two proteins are being expressed.
Multiple Alleles
Characters that are controlled by more than two alleles.
Pleiotropy
Most genes have multiple phenotypic effects.
Epistasis
One gene can affect other genes.
Polygenic Inheritance
Characters vary in the population in gradations, indicating polygenic inheritance.
Pedigree
A family tree that traces the inheritance of a particular trait within a family and can tell you whether or not you or your children have inherited or will inherit a disease.
Cystic Fibrosis
Causes a build-up of mucus in the lungs and digestive tract which clogs airways and blocks digestion.
Sickle Cell Disease
Causes blood cells to become sickle-shaped which can clump up and clog blood vessels; also causes physical weakness, anemia, heart failure, etc.
Achondroplasia
Dwarfism caused by autosomal dominant disorder.
Huntington's Disease
A fatal degenerative disease of the nervous system. This gene has little affect until the person is in their 30s or 40s.
Amniocentesis
Extraction by centesis of amniotic fluid from a pregnant woman (after the 15th week of pregnancy) to aid in the diagnosis of fetal abnormalities
Chorionic Villus Sampling
A technique of prenatal diagnosis in which a small sample of the fetal portion of the placenta is removed and analyzed to detect certain genetic and congenital defects in the fetus
Wild Type
An individual with the phenotype most commonly observed in natural populations.
Linked Genes
Genes are located on the same chromosome that tend to be inherited together.
Recombinants
Form during Prophase I when the homologous chromosomes pair up and chromatids cross over.
Linkage Map
Genetic map of a chromosome based on recombination frequencies.
Cytogenetic Map
Indicates the position of genes with respect to chromosomal features an a genetic map is an ordered list of the genetic loci along a particular chromosome.
Methylation
Silences an allele, but it can also activate the expression of an allele.
X inactivation
This occurs in mammalian females when one of the two X chromosomes in each cell is randomly inactivated during embryonic development.
Barr Body
A highly condensed inactivated x chromosome.
Aneuploidy
Results from the fertilization of gametes in which nondisjunction occurred.
Monosomic
Zygote that only has one copy of a particular chromosome.
Polyploidy
A condition in which an organism has more than two complete sets of chromosomes.
Deletion
The removal of a chromosomal segment.
Duplication
A repeat of a chromosomal segment.
Inversion
Reverses a segment within a chromosome.
Translocation
Moves a segment from one chromosome to another.
Down syndrome
An anueploid condition that results from three copies of chromosome 21
Klinefelter Syndrome
The result of an extra chromosome in a male, which produces XXY individuals.
Turner Syndrome
Produces X0 females, who are sterile; it is the only known livable monosomy in humans.
Chromosomal Theory of Inheritance
A basic principle in biology stating that genes are located on chromosomes and that the behavior of chromosomes during meiosis accounts for inheritance patterns.
/ 62
Term:
Definition:
Definition:

Leave a Comment ({[ getComments().length ]})

Comments ({[ getComments().length ]})

{[comment.username]}

{[ comment.comment ]}

View All {[ getComments().length ]} Comments
Ask a homework question - tutors are online