B=black and b=brown. a bb guinea pig crosses with a bb guinea pig, and four offspring are produced. all of the offspring are black. explain how this could happen.

If two Bb guinea pigs cross, there are four possible outcomes:

Since B (being black) is dominant, the son will be black in both BB and Bb cases. In order for a son to be brown, he must be a pure bb specimen.

So, if all of the offspring are black, it means that all four guinea pigs are either BB or Bb, which in turn means that at least one of the parents passed the B gene.

littering streams           is the answer

1 digestive system

2 stomach

3 bladder

4 carbon deoxide

5 tiger