Basics of heredity – core principles
How it works
Heredity describes how genetic information is passed from parents to offspring. Important foundations were described by Gregor Mendel in pea plants. Genes are sections of DNA and are located on chromosomes. Many traits are influenced by the interaction of genes and the environment. In simple Mendelian examples, there are different alleles of a gene; some act dominantly, others recessively. Homozygous means that both alleles are the same, heterozygous that they are different. The environment can influence the phenotype. In addition, some environmental factors can cause mutations; such changes are inheritable only if germ cells are affected.
In simple Mendelian examples, traits are inherited according to certain rules. A dominant allele can mask the recessive one in the phenotype in a heterozygous genotype. Mendel's laws help describe typical crosses with clear allele pairs, but they do not fully explain all traits.
An example
What does it mean if an individual is homozygous for a specific gene?
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50 Exercises
To the learning unit →Own explanation and own practice exercises by AmyMath. Subject reference framework: Biology. The topic assignment may vary by federal state.