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How are traits passed from parents to offspring?
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heredity
Each offspring is a combination of its two parents, receiving some dominant traits from its mother and others from its father.
Traits are passed from parents to offspring through the transmission of genes, which are the functional units of heredity located on chromosomes. In sexually reproducing organisms, offspring inherit half of their genetic material from each parent.123
The process is governed by the following principles:
- Meiosis and Segregation: During the formation of sex cells (gametes), paired chromosomes separate so that each gamete receives only one member of each chromosome pair. This ensures that when fertilization occurs, the offspring receives a complete set of paired genes—one from each parent.14
- Alleles and Genotype: Genes exist in alternative forms called alleles. An organism's genotype is the specific combination of these alleles. If an individual inherits different alleles, a dominant allele may mask the expression of a recessive one, meaning the recessive trait is only expressed if two copies are inherited.513
- Independent Assortment: Alleles for different traits located on separate chromosomes are inherited independently of one another, contributing to genetic variation among offspring.14
- Crossing Over: During meiosis, chromosomes can exchange segments, creating new combinations of genes and further increasing diversity.4