Answer: They have a backbone
Explanation: Humans and fish are both vertebrates. Vertebrates are organisms with a backbone.
Answer:
I believe it is D.
Explanation:
Ecological succession has to do with how the habitat changes over time. So D would make the most sense.
Answer:
A male and a female have sexual interactions. While this, the male releases sperm cells which go into the females egg cells. This then forms into a baby and slowly grows. Then about nine months later the baby comes out of the females vagina.
The answer should be nucleus