Who proposed the Pure Line Theory?

✅Explanation:
Wilhelm Johannsen, a Danish botanist, proposed the Pure Line Theory in 1903. The theory states that a pure line is a population of individuals derived from a single homozygous self-fertilized plant. These individuals are genetically identical and will breed true, meaning their offspring will have the same traits as the parent.

📌Other Options:
(b) Jensen (1952): Jensen is primarily known for his work on "bulk breeding", a technique used in plant breeding to improve self-pollinated crops. He suggested this method for advancing segregating generations.
(c) Nilsson Ehle (1908): Nilsson Ehle is known for his work on quantitative genetics and the multiple factor hypothesis.
(d) Goulden (1939): Goulden was a key figure in the development of statistical methods in genetics. He made significant contributions to the understanding of quantitative genetics, particularly in the areas of experimental design and data analysis. He is credited with first suggesting the use of the "single seed descent" breeding method for advancing segregating generations of self-pollinated crops.