Yes. Not at once, of course.
When a female is in heat she will accept more than one male to breed with. If there are enough eggs, the sperm from more than one male can fertilize different eggs the female has.
There is a myth that having a litter of pups can calm a female dog. This isn't true, having a litter can make a female dog more protective, because she has babies to guard. Proper socialization, training and spaying will correct temperament problems.
A sire is a male dog who is the father of a litter of puppies.
No actually a female dog is more calm. so the female dog is better behaved than the male dog
yes, up to four.
They shouldn't have more than 4 or 5 litters, depending on how healthy and strong the dog is, as well as at what age the dog got her first litter.
It is inhumane to let a dog have more than two or three litters in a lifetime.
Yes a litter can be fathered by more than 1 sire.
Different pups in the same litter may be sired by different fathers.
Yes, there can be two dads to one litter.
Cats are one of the few species capable of fertilization by multiple partners on a regular basis. Technically, each kitten in a litter can have a different father, but it is not quite that likely. However many mate with the queen while she's in heat!
Simply because the female produces more than one egg when she's in season.