Final answer:
Genetic inheritance was comprehended before the specific composition of genes was known. This understanding hin_ged on the foundational work of Gregor Mendel in the 19th century and the later identification of DNA bases by scientists like Albrecht Kossel.
Step-by-step explanation:
Genetic inheritance was understood before it was known what genes were made up of. By the late 19th century, it was established that the nucleus of eukaryotic cells contained genetic information, consisting primarily of proteins and DNA. The award of the Nobel Prize to Albrecht Kossel in 1910 for identifying the four DNA bases and uracil in RNA highlighted the advancing understanding of nucleic acids. However, the role of DNA in heredity wasn't fully recognized until later. Gregor Mendel's laws of heredity were formulated based on his experiments with pea plants during the 1850s and 1860s, but it was only decades after that DNA's role in heredity was accepted, thanks to the integration of Mendelian genetics with the study of chromosomes.
During Mendel's time, inheritance was inferred from the appearance of traits in offspring, but today, geneticists can visualize an individual's chromosomes using a karyogram. This allows for confirmation or prediction of genetic abnormalities even before birth. This advancement, along with the historical contributions from scientists like Mendel and Kossel, has led to the robust field of genetics that we understand today.