Answer:
Invertebrates include all animals that lack a backbone, or a vertebral column. All chordites exhibit four characteristics during at least one stage of life: a dorsal, hollow nerve chord; a notochord; a tail that extends beyond the anus; and pharyngeal pouches.
Answer: a compound known as calcium carbonate (CaCO3)
Explanation: Google the question itself
The answer is d, since air is a muxture of compounds. a way to differentiate between a muxture and a compound is to see it it is a word you would say normally. for example, you would say air on a normal day. however, you wouldn't say carbon monoxide on a normal day.
hope it helped! :)
Answer:
mRNA is produced in the nucleus.
