Lecture 6- Inbreeding And Heterosis.ppt _best_ «AUTHENTIC»

| Hypothesis | Explanation | |------------|-------------| | | Recessive deleterious alleles masked in F1; dominant beneficial alleles from both parents combine. | | Overdominance hypothesis | Heterozygote at a locus is superior to either homozygote (e.g., sickle-cell trait in malaria regions). |

| Trait Affected | Effect of Inbreeding | | :--- | :--- | | | Sperm abnormalities, lower litter size, higher embryonic mortality | | Growth Rate | Reduced weaning weight, slower daily gain | | Survival | Higher juvenile mortality, reduced immune competence | | Yield (Crops) | Smaller seeds, lower grain production | | Physiological | Higher incidence of genetic defects (e.g., hip dysplasia in dogs, cleft palate in cattle) | Lecture 6- Inbreeding and Heterosis.ppt

Inbreeding does not create bad genes—it exposes them. By forcing homozygosity, it removes the masking effect of a dominant healthy allele. By forcing homozygosity, it removes the masking effect

"Heterosis fixes good traits permanently." By forcing homozygosity

Genetic Consequences of Mating Between Relatives & The Power of Hybrid Vigor

by increasing the probability that two alleles at a locus are Identical by Descent (IBD) Inbreeding Coefficient (