In purple people eaters, one-horn is dominant and no horns is recessive. If purple people eater that is hybrid for horns is crossed with a purple people eater that does not have horns, what is the likelihood that their offsping will have horns?
1. HH.
2. Hh.
3. hh.

Which of the following must be true for a fossil organism to be useful as an index fossil? a. the fossil organism must be widespread geographically. b. the fossil organism must be abundant. c. the fossil organism must be limited to a short span of geologic time. d. all of the above.