Just the Facts
Date of this Version
Plant and Soil Sciences eLibrary (PASSeL) Lesson
Description of the fundamental concepts of trait inheritance in sexually reproducing species.
You have probably noticed that parents share many or most of their traits with their offspring. This observation came to the attention of humans long before scientific investigation developed. Human curiosity about the basis of trait inheritance is long standing, but most of what we know about genetics has emerged through research from the past 100 years. The fundamental concepts of trait inheritance in sexually reproducing species will be described in this lesson. The classical experimental approach that revealed these principles will be described in the following two lessons. For now, we will focus just on the facts of how variation is inherited.
- Lesson home
- Concept 1: Sexually reproducing organisms make sex cells or gametes.
- Concept 2: Genes are stable, passed on in sex cells and control traits
- Concept 3: Genes are a part of the chromosome and are found in pairs in somatic cells.
- Concept 4: Genes can change on occasion and the alternative version or allele may control the trait
- Concept 5: Individuals can be homozygous or heterozygous.
- Concept 6: Gene pairs associate and then separate during gamete formation
- Concept 7: Gametes combine at random to form the individuals in the next generation.
- Concept 8: One allele can be dominant over another or show a lack of dominance.
- Concept 9: The segregation of genes allows geneticists to make predictions.
- Concept 10: Segregation can be predicted based on independent assortment.