Chordates are called chordates because they have a spinal chord, so the answer is C.
The correct option is A.
Environmental DNA surveillance is used for detection and monitoring of invasive animal species in aquatic and terrestrial ecosystem. The surveillance method provides information for the management personnel about the existence of alien species or outbreak of diseases. Early detection is always crucial in this case in order to prevent fatal consequences.<span />
Answer: changed by molecular oxygen
Explanation:
Biologically induced molecular oxygen (dioxygen, O2) started to accumulate in Earth's atmosphere and changed Earth's atmosphere from a weakly reducing atmosphere to an oxidizing atmosphere.
Answer:
I would say it is E.
Explanation:
because fish, penguins, and dolphins are aquatic animals. It can't be A. because if it were vestigial it would be useless. It can't be B even though it does seem like the right answer because the are all aquatic. It can't be C. because it would been that the same species would have the same niche which is not possible. It can't be D. because every organism is evolved from a common ancestor.
