Planarian
ask your mom
Beak
No, just a fast digestive system.
it all depends on the animal, cow for example, have 4 organs that are like a stomache. birds, have a very different digestive system.
Cedar berries are eaten by birds, and pass through their digestive system. When the birds poop, the seeds grow where they land.
Y in the worldwide should i k n or care
The male is nourished by the female but if the female does not return with food once the chick has hatched, he produces 'penguin milk' from his digestive system and regurgitates it for the chick. The young birds go to sea at about five months.
Yes, the human digestive system works through muscular contractions which force the food and liquid along. This is why we have no problems in space (apart from getting the food to stay on the plate). You can demonstrate this by hanging upside down and eating a sandwich just fine. Interestingly, the digestive system of many birds does depend on gravity; this was discovered during a Space Shuttle mission to see if birds could handle space.
There is evidence to suggest that some fish eggs might be able to survive the trip through a bird's digestive system. This explains how some species of fish end up where they may not belong.
Birds + incomplete mechanism
The function of the crop in the digestive system of the the bird is to temporarily store food for later digestion. In seed eating birds the crop is like a pouch in the esophagus and no real digestion occurs there it occurs in the gizzard which grinds it all up.
Any seed in a berry. Birds eat the fruit, and they often pass through the digestive tract unchanged, then they are deposited elsewhere (complete with their own dose of fertilizer!).