Yes, plums need the correct pollinator. The right one depends on which variety you have.
Not necessarily. Plants have both female reproductive parts and male parts. They can self-pollinate.
No.
Unfertilized flowers do not produce fruit. Some flowers are self-pollinating, which means that you do not need two to pollinate. These are still pollinated in order to produce fruit.
Yes. Their blossom times will overlap and both produce plenty of good pollen. However, neither need pollination in order to bear fruit; the fruit will just end up seedless.
No, taking out the anther won't make a flower convert into a fruit. In order to pollinate and fertilize the ovules (eggs) inside the flower's ovary, pollen must be produced and released by the reproductive organ known as the anther. A flower cannot turn into a fruit without effective fertilization and pollination.
That is simply the variety of fruit that they produce in order to facilitate spreading of seeds.
The Black Tartarian cherry tree needs to be pollinated by another cherry variety (Bing or another sweet cherry variety will do) in order to properly develop its fruit. Although the fruit can not develop without the tree having flowered first, flowering alone does not guarantee that the tree will set fruit.
Most Kiwi plants require a male and a female plant in order to produce fruit. Very difficult to tell a male from a female Kiwi plant.
No, cicadas do not function as pollinators. As members of the True Bug order Hemiptera, the Cicada has piercing and sucking mouthparts. They primarially pierce the twigs of bushes and tress and then feed on the sap within. Since they are not attracted to flowers there is no way for them to intentionally or unintentionally pollinate anything.
It depends on the type of apple tree, some are self pollinating and some need other trees pollen in order to pollinate.
Actually, in order to stimulate fruit growth you can strike your tree or you can have another fruit sit on top of your tree and that should stimulate growth in your "fruit".
There are a number of bushes and shrubs that produce edible fruit. For example, Burncoose Nursuries sells a number of these bushes by mail order, such as the Cydonia Oblonga or the Acca sellowiana.
No they are to totally different types of plants, Marigold = Tagetes and African Daisy = Diamorphotheca. In order for them to cross-pollinate they have to be compatible at least at a genus level
they smell like a corpse to attract insects, and the insects pollinate them.