<span>A. endoskeleton
</span>Endoskeleton is not a characteristic of Arthropods that has attributed to their diversity and success. Endoskeleton is defined as inner characteristics of the skeletal feature of an organisms such as bears, humans, fish and etc.
Exoskeleton on the other hand is the trait by which arthropods posses. It is skeletal feature that is described outside or is extrinsic, this is evident as crabs have their skeletons outside of their body.
I believe it would be a fossil of a reptile but I'm not a 100% sure about it.
We do quite often have mutt birds. (the correct name for such a mutt is a hybrid. <span>They are way more common than most people think, but unless you are a birdwatcher you probably wouldn’t even spot them. People often see an odd looking birds and simply think it’s a type they haven’t seen before, when in fact it is a hybrid of two well-known species.
Having said that, for birds to hybridized they have to be fairly closely related to start with. Robins and blue jays are no more closely related than humans are to baboons. You wouldn’t expect a human and a baboon to be able to mate and produce babies would you? So no, robins and blue jays can’t interbreed.
However there are many different species of animal that CAN interbreed and produce offspring. But the different species need to be fairly closely related, far more closely than human and baboon… or a blue jay and a robin.
For example we can interbreed horses and donkeys to produce baby mules, and we can breed cattle and buffalo, or camels and llamas. And the same is true of birds. While blue jays can’t be bred with robins in the wild we quite frequently find mutt birds.
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Ducks are particularly noted for forming wild mutts and many if not all north American mallards for example are of mixed species ancestry.</span>
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Answer:
Due to lack of nutrients in the soil.
Explanation:
Within a few years the forest was dying because there is no nutrient is present in the soil which can trigger the growth and development of the sol. The fallen parts of trees such as branches, tree and leaves etc are decomposed by decomposers such as bacteria and fungi which turn the fallen materials into nitrogenous materials which can be used by the plant for its growth and development.