We know that domestic dogs are descended from wolves. Exactly when and how this occurred is still being studied; many experts indicate that dogs were first domesticated about 12,000 years ago, but a few DNA studies indicate a much earlier date for the split between the wolf and the dog, perhaps as long ago as 130,000 years.
Regardless of the exact timing of the divergence between wolves and dogs, one thing is true: both species display quite a bit of genetic diversity, particularly in size and coloration.In order to breed a dog of a specific size, all one has to do is choose parents with the appropriate variations. For instance, if you want to create a small dog breed, you would just breed the smallest dogs you have, then you would choose their smallest offspring to breed the next generation, and so on until you have reached the desired size.
8. The picture that would best represent atoms in the gas of a neon sign is the image B. This
is because they have room for movement in that their distance between each
particle is great. That is why gases has greater volume compared to liquids and
solids.
<span>9. The picture that would best represent a rock is the image C. The solid molecules are so pact that they have no room for movement.</span>
Physical change: a change in which no new substances are formed. the form of the substance is changed but not it's chemical composition (ice melting, bread toasting)
chemical change: any change that results in the formation of new chemical substances. this type of change modifies molecules and atoms by making and breaking the bonds between atoms! (iron rusting, gas burning)
so basically a physical change just changes the appearance of a substance, but a chemical change changes the makeup on a molecular level. i hope this helps you out!
i think that it is the tree
