~Meiosis and genetice~ Flashcards
Meiosis
Division of sex cells to produce four unique, new cells.
Gamete
Sex cells
Haploid cell
Cell that contains only half of the genetic information
Crossing over
When homologous chromosomes trade fragments of genetic information during prophase 1
Independent assortment
The random assortment of chromosomes during metaphase 1.
Allele
Different forms of a gene type
Genotype
Genetic makeup; letters used to represent alleles; examples TT, Tt, tt
Phenotype
Physical appearance based on inherited traits; observable traits.
Dominant trait
Stronger allele; trait that is shown; masks or hides the recessive.
Recessive trait
Weaker allele; trait can be hidden or masked by stronger alleles.
Homozygous
Pure; two of the same alleles for a trait; Example: TT or Tt
Heterozygous
Hybrid; two different alleles for a trait; Example: Tt
Carrier
Individual that shows the dominant trait, but has or “Carries” a recessive allele.
Polygenic inheritance
Trait is controlled by more than one allele. (ex. eye color, hair color…)
Codominace
Both alleles are dominant and expressed together.
Incomplete dominance
Neither allele is dominant. Instead a blend of the two alleles is expressed.
Sex - linked traits
Traits carried by the x chromosome; examples: color blindness and hemophilia
Pedigree
Genetic representation of a family tree
Nondisjuction
When chromosome pairs fail to seperate during meiosis; can be detected with karyotype.
Karyotype
Chart of a paired chromosomes; can identify sex and abnormal numbers of chromosomes.
