Many qualities do not inherit according to Mendelian genetic rules.

• When the observed ratios of phenotypes in kids do not match the ratios predicted by the Punnett squares and Mendelian laws, it might be due to linked genes, multiple genes coding for the trait, nonnuclear inheritance, or even environmental impacts on the phenotype.

• The term "linked" refers to genes that are near together on the same chromosome.

• Because linked genes exist on the same chromosome (a lengthy stretch of DNA), they are more likely to be inherited together than unlinked genes (which are on separate chromosomes).

• Genetic recombination between connected genes may occur during prophase I of meiosis.

The majority of genes are found on autosomes, which are chromosomes that are not directly involved in sex determination.

• Males and females are equally likely to inherit autosomal genes.

• Sex chromosomes play a role in determining sex, and genes on sex chromosomes inherit differently than those on autosomes.

• Sex-linked genes are a subset of linked genes.

• Sex-linked genes are genes found on sex chromosomes.

As a result, because men have only one X chromosome, features coded for by sex-linked recessive genes are more likely to be expressed.

• Females might exhibit a sex-linked recessive trait as well, but since they have two X chromosomes, a female would need to receive the trait's gene from both parents in order to display it.

• When looking at a pedigree, if there are more males than females with the characteristic, it is likely that the trait is coded for by a gene on a sex chromosome.

Hemophilia and color blindness are two examples of sex-linked recessive traits in humans.

• Humans have sex-linked dominant features, although they are extremely rare.

• Because all females inherit an X chromosome from their father, if a male possesses a sex-linked dominant characteristic, all of his daughters will inherit the trait.

• If a mother possesses a sex-linked dominant characteristic, both her sons and daughters have a 50% chance of acquiring the trait.

• Some qualities are formed by many genes cooperating to produce the phenotype.

• Because more than one gene is involved in the production of the characteristic, the ratios anticipated by Mendelian rules would not apply.

• Height and eye color are two features that are created by numerous genes.

• For example, suppose three genes (A, B, and C) affect plant height, and each dominant allele present in the three genes has an additive effect on the plant's height.

• The more dominant alleles a plant acquires, the taller it will grow.

• A plant with the genotype AABBCC would grow to be very tall, whereas a plant with the genotype aabbcc would grow to be quite short.

A plant with the genotype AaBbCc would be in the center of the range in height.

• It should be noted that several alternative genotypes (for example, AAbbCc or AaBBcc or aaBbCC) might result in a plant with a height in the middle of the range.

• Mitochondria and chloroplasts each have their own DNA that is distinct from nuclear DNA.

• Genes on mitochondrial or chloroplast DNA do not exhibit the same inheritance patterns as genes on nuclear DNA.

• During gamete production, the eggs produced by animals and the ovules produced by plants are significantly bigger than the sperm (in animals) or pollen (in plants) produced.

• Because eggs and ovules are bigger than sperm or pollen, they contribute considerably more mitochondria and mitochondrial DNA (mtDNA).

• In plants, ovules contribute more chloroplast DNA (cpDNA) than pollen.

As a result, features on nonnuclear DNA in mitochondria or chloroplasts show maternal inheritance.

• Characters can be handed down from mother to son.