IndietroMendelian Genetics and Inheritance Patterns
01:58
Termini in questo insieme (20)
Each gamete carries only one allele for a trait because alleles segregate during meiosis I when homologous chromosomes separate.
Alleles of different genes located on different chromosomes assort independently into gametes during meiosis.
A test cross of a dihybrid heterozygote with a homozygous recessive produces four phenotypes in a 1:1:1:1 ratio, showing independent assortment.
Genes located close together on the same chromosome tend to be inherited together, reducing independent assortment.
Crossing over during meiosis can separate linked genes, allowing some recombination of alleles.
Traits caused by genes on sex chromosomes, often X-linked, show different inheritance patterns in males and females.
Males are more likely to express recessive X-linked traits because they have only one X chromosome.
A gene can have more than two alleles in a population, creating more genotype and phenotype variation.
The same genotype can produce different phenotypes depending on environmental conditions.
One allele completely masks the effect of another in heterozygotes, producing only the dominant phenotype.
Heterozygotes show an intermediate phenotype between the two homozygotes.
Both alleles in a heterozygote are fully expressed, such as in human ABO blood types.
One gene affects multiple phenotypic traits.
Multiple genes influence a single trait, often modifying phenotypic expression.
Many genes contribute additively or multiplicatively to a continuous trait, like height or skin color.
F1 offspring show only the dominant phenotype; F2 offspring show a 3:1 dominant to recessive phenotype ratio.
Genotype is the genetic makeup; phenotype is the observable trait resulting from genotype and environment.
Homozygous: two identical alleles; heterozygous: two different alleles for a gene.
A tool to predict offspring genotypes and phenotypes from parental genotypes in genetic crosses.
Males produce gametes with X or Y chromosomes; females produce gametes with only X chromosomes, determining offspring sex.