Not all features of father or mother shall be inherited by the offspring (equally). We try to select our preferred characteristics: yield, growth rate, taste..
Like at people a dark skin is dominant and bright, brown eyes are dominant over blue eyes, etc. so are in plants almost always green leaves dominant over variegated leaves, and the flower head color almost always dominant.

A chromosome is made up of strands of DNA (deoxyribonucleic acid), found in each cell and copied at each cell division.
The DNA contains by the sequence of nucleotides the codes in which all our inherited properties are defined.
A gene is a specific piece of DNA with a fixed position on a chromosome, which contains the information for the formation of a protein, which receives specific tasks and functions (e.g. blood,..).
Different variants of the same gene can occur, called alleles (e.g. for brown or blue eyes).

An organism is homozygous for a certain trait as it has two identical copies of a gene in a chromosome pair, so if both parents pass the same allele for a gene to their offspring. The offspring is therefore also homozygous.

A heterozygous organism has two different forms (alleles) of a gene (e.g. blue and brown eyes).

Crosses between homozygous and heterozygous
 Parents: AA x Aa
 Sex Cells: A /A x A /a
 Progeny: 50% AA and 50% Aa

Crosses between heterozygotes
 Parents: Aa x Aa
 Sex Cells: A /a x A /a
 Offspring: 25% AA, 50% Aa, 25% aa

The ability to retain properties through intersection (and to strengthen them) is also used in the breeding of cattle. You can also use it when growing little people.

When I let grow once carrot and parsley close together and form seed, a year later I had a lot of spontaneous seedlings. Probably edible. But not tasty. Neither the carrot nor the foliage.

A molecular trace of the trauma is visible in the sperm of previously abused men.
At twelve different locations on the DNA there were more methyl groups (epigenetics) in the previously abused participants than in the volunteers without trauma. Children whose parents have been abused as children are more likely to develop abnormalities in neurological development or physical health. A trauma can therefore have consequences over generations.

The main engine of evolution at micro level is a real highway with an effective way to exchange genetic material between bacteria. For this, bacteria use the services of bacteriophages (or simply 'phages'). These are viruses that parasitize on bacteria. Phages penetrate the bacterial cells and propagate with the help of the bacterial DNA. When they look for other bacteria, they take pieces (copies) of the DNA. Through this horizontal DNA exchange, new mutations (and resistance) can spread rapidly over a population.

"My vision on evolution is that Darwin was an adopted child." (Steven Wright)
Heredity: in what one believes when one has an intelligent child. (Alfred C. Kinsey)
The woman's intuition is the result of millions of years not thinking. (Rupert Hughes)
Hereditary: I want to be smart like my dad. Who wants to be smart to.