Answer:
They digest without the use of teeth.
Explanation:
The food trickles from the crop into the bird's stomach (proventriculus or gizzard) where digestive enzymes are added to the mix and physical grinding of the food occurs. The gizzard is why chickens do not need teeth.
Answer:
Because the biodiversity decreases.
Explanation:
An ecosystem is richer when it has a higher biodiversity, remember that each living thing has an specific role in the food web. When in an ecosystem this web is bigger, increases the probability of sustain a living thing. For example, in the sea, if there is a fish, this is going to be more probabilities of survive if this fish can eat different plants or other fish. But if in the ecosystem there are not a variety of them, it probability to survive is less if one of it food desapear.
Because they are non renewable sources of energy and they took billions of years to form.
Answer:
For recessive traits to be observed, dominant genes must be absent.
Explanation:
There are 3 possibilities for the genes: AA, Aa, aa.
in both AA and Aa, there is a dominant gene present. If a dominant gene is present, it will always show the dominant trait.
In aa, there is no dominant gene present, and there are only recessive genes. Because of this, the recessive trait is observed!
