Unit 4: Genetics Flashcards
(42 cards)
Chromosomes
Holds DNA
Humans have 23 homologous pairs (46 total)
Genes
Transferred from parent to offspring
Law of independent assortment
the allele a gamete receives for one gene does not
influence the allele received for another gene
Law of dominance
If there is a dom allele present that is the gene that is expressed
Genotypic ratio
Homo dom : Hetero : Homo rec
Phenotypic ratio
Dom : Rec
DNA
the molecule that carries genetic information
Allele
versions of a genetic sequence
EX: RR, Rr, rr
Law of segregation
During the formation of gamete, each gene separates from each other so that each gamete carries only one allele for each gene
Genotype
Homozygous dominant, heterozygous, homozygous reccesive
Phenotype
The physical characteristic
Karyotype
an individual’s complete set of chromosomes
Punnet Square
The square used to do genetic crosses
Dihybrid
the mating of two organisms that are heterozygous for the same two traits
(identical)
Test cross
A genetic cross in which a test organism showing the dominant trait is crossed with one showing the recessive trait
used to determine whether the test organism is homozygous dominant or heterozygous.
Homozygous
The same
Recessive
expresses rare trait / less common
Haploid
the presence of a single set of chromosomes in an organism’s cells
Gamete
a male or female reproductive cell, such as a sperm or an egg
Fertilization
the union of two gametes
Monohybrid
hybrid of two individuals with homozygous genotypes
Pedigree
Family tree with genotypes to track different traits
Rule of multiplication
When we calculate probabilities involving one event AND another event occurring, we multiply their probabilities
Heterozygous
