Q.Select the period for Mendel's hybridization experiments

Mendel's laws were independently rediscovered in 1900 by Hugo de Vries, Carl Correns, and Erich von Tschermak.

Working

Gregor Mendel presented his laws of inheritance, based on his hybridisation experiments on garden pea, in 1865 and published them in 1866, but his work went largely unnoticed by the wider scientific community for about 34 years. In the year 1900, three botanists working independently in different countries -- conducting their own hybridisation experiments on various plants and arriving at conclusions that closely paralleled Mendel's -- each rediscovered essentially the same principles of inheritance:

1. Hugo de Vries (in the Netherlands), who had worked on evening primrose and other plants.
2. Carl Correns (in Germany), who had worked on maize and peas, and who later also discovered cytoplasmic/extranuclear inheritance in Mirabilis jalapa.
3. Erich von Tschermak (in Austria), who had worked on pea hybridisation. …

Mendel's principles of inheritance were independently rediscovered in 1900 by Hugo de Vries, Carl Correns, and Erich von Tschermak.

Gregor Johann Mendel published his landmark findings on inheritance in garden pea (Pisum sativum) in 1866, but his work went largely unnoticed by the scientific community of his time and remained obscure for about 34 years.

In the year 1900, three botanists working independently in different European countries, each conducting their own hybridisation experiments on different plant species, arrived at conclusions strikingly similar to Mendel's -- and each, upon reviewing prior literature, discovered that Mendel had already described these same principles decades earlier:

1. Hugo de Vries (the Netherlands) -- working on evening primrose (Oenothera) and other species.
2. Carl Correns (Germany) -- working on maize and peas. …

Mendel founded genetics by using a quantitative, statistical approach to plant-breeding experiments, from which he derived the basic laws that govern how traits pass from parents to offspring.

Gregor Johann Mendel (1822–1884), an Austrian monk, worked with the garden pea plant for about seven years (1856–1863) in the monastery garden at Brno.

Why his work was pioneering:

1. Choice of material — Pisum sativum has several advantages: it is self-pollinating (but can be cross-pollinated by hand), has a short life cycle, is easy to grow, and shows several easily distinguishable, contrasting (either/or) traits, e.g. tall/dwarf stem, round/wrinkled seed, yellow/green cotyledon.
2. Quantitative approach — Unlike earlier naturalists who only described what they observed, Mendel counted the numbers of offspring showing each trait over several generations and analysed the ratios mathematically (e.g., the 3:1 and 9:3:3:1 ratios). This statistical rigour was new to biology.
3. Hybridisation and generations — He crossed true-breeding (pure) plants differing in one or more traits and followed the traits through the F1, F2 and further generations, rather than just observing a single cross.
4. The laws he formulated:
   • Law of Dominance — in a heterozygote, one allele (the dominant one) masks the expression of the other (recessive) allele.
   • Law of Segregation — the two alleles of a gene separate (segregate) from each other during gamete formation, and each gamete receives only one allele.
   • Law of Independent Assortment — alleles of different genes (located on different chromosome pairs) assort independently of one another during gamete formation. …