14. Dermis
15. Chemical
17. Virus
18. Antibodies
19. Gas exchange
20. Ligament
Hope this helps!
Answer:
It is possible to produce an offspring from a zebra mating with a donkey. Indeed, in Florence, Italy, a male zebra mated with a female donkey and produced a striped mule.
Mitochondria should be the answer
The answer should be both