Question 3
A homozygous tall plant is crossed with a homozygous dwarf one. What are the offspring?
The right answer is the one marked above.
All Tt. The tall parent can only make T gametes and the dwarf parent can only make t gametes, so every offspring gets one of each. Every plant is tall, and every plant carries a hidden t.
This is why crossing two homozygotes gives a uniform F1: neither parent has more than one kind of gamete to offer.