Plants
If they are plants (e.g. spotted knapweed) they produce seeds to reproduce, because they are plants that produce seeds to reproduce. If they are animals (e.g. brown tree snake) they do not produce seeds, because animals do not reproduce by producing seeds.
Yes, all sunflowers produce seeds.
Yes, dwarf sunflowers do produce seeds.
Orchards are groups of fruit trees, so the produce fruit, therefore they produce seeds.
Yes, bluebells do produce seeds. After the flowers are pollinated, they develop into seed capsules that contain the seeds.
Angiosperms and gymnosperm plant types both produce seeds
Oddly enough they produce guava seeds.
cacti are flowering plants and produce seeds
Because dry seeds have a very low metabolic rate and do not produce much Co2. Germinating seeds produce more Co2.
No, not all sunflowers produce sunflower seeds. Some varieties of sunflowers are grown for their ornamental flowers and do not produce seeds suitable for consumption.
No Yeast cells produce spores which serve the same function as seeds
Usually, bigger plants do produce bigger seeds.