How are traits passed from parent to their offspring?

DNA is the molecule that makes up our chromosomes, which in turn contain thousands of genes. Genes direct the production of proteins according to the genetic code and these proteins are needed for life processes to occur, building the body's structure, are components of cell membranes, muscles, hormones and enzymes. 

Organisms inherit traits via the process of fertilization. At that moment, a haploid sperm nucleus and an egg nucleus also haploid, fuse together creating...

DNA is the molecule that makes up our chromosomes, which in turn contain thousands of genes. Genes direct the production of proteins according to the genetic code and these proteins are needed for life processes to occur, building the body's structure, are components of cell membranes, muscles, hormones and enzymes. 

Organisms inherit traits via the process of fertilization. At that moment, a haploid sperm nucleus and an egg nucleus also haploid, fuse together creating a diploid fertilized egg or zygote. It is from this cell that the genetic blueprint for all the cells to follow within the organism has been determined. 

Our genes are found in pairs because each parent has supplied a set to the offspring. Specific laws based on the work of Gregor Mendel can be applied to the gene pairs to determine the traits seen in the phenotype of an offspring. Different versions of a gene are called alleles. If for example, an offspring inherits a dominant allele and a recessive allele, although both are present in the organism, the dominant one will be expressed in the phenotype.

Sometimes, incomplete dominance is seen in a specific trait where two different genes blend together. For example, in Japanese four o clock flowers, if a plant inherits a red allele and a white, they blend to form a pink offspring.

Sometimes, traits can be co --dominant where they are both fully expressed in the offspring. Hence, a person with the gene for type A and the gene for type B blood will have type AB where the blood cells contain both the A and B antigens.

Traits may be linked to the X chromosome. Males have one X and are hemizygous for genes on that chromosome. Females have two X chromosomes. Many times, males inherit X linked traits from their mothers who are carriers. 

By using the information and rules discovered by Mendel and others in the field of genetics, we can apply that information to make predictions of what type of offspring a pair will produce, provided that their genetic makeup is known.