Final answer:
Vertical transmission occurs when a pathogen or genetic trait is transmitted from parent to offspring, in contrast to horizontal transmission, which occurs between individuals of the same generation.
Step-by-step explanation:
Transmission that occurs from a parent to its offspring is classified as vertical transmission.
Vertical transmission is commonly seen with diseases that can affect both a pregnant woman and her child, such as HIV infection and rubella. It is also observed in the inheritance of plant viruses from parent plants, as well as certain genetic disorders that follow a pedigree pattern in autosomal dominant diseases.
This type of transmission stands in contrast to horizontal transmission, where a pathogen is transmitted between individuals of the same generation. Horizontal transmission includes various modes like fecal-oral spread, sexual activity, or through vectors such as ticks and mosquitoes. An example would include sexually transmitted infections like chlamydia and gonorrhea, or diseases such as cholera which are spread via contaminated food or water. Understanding these modes of transmission is crucial for the prevention and control of infectious diseases.