Which one from those given below is the period for Mendel's hybridisation experiments?

When a homozygous tall plant is crossed with a homozygous dwarf plant,what is the percentage of dwarf progeny obtained in the $F_1$ generation by Mendel (in $\%$)?

In Mendelism,linkage was not observed due to

$F_1$ generation Mendel pollinated a pure-breeding tall plant with a pure-breeding dwarf plant. But for getting the $F_2$ generation,he simply self-pollinated the tall $F_1$ plants. Why?

In $Pisum$ $sativum$,two of the seven traits studied by Mendel were linked,as they are located on chromosome number $4$. These traits were:

Identify the recessive character of the pea plant studied by Mendel.