Ajellyfish is a type of cnidarian, a squid is a type of mollusk, and a dolphin is a type of vertebrate. which two characteristics are present in both a squid and a dolphin, but not present in a jellyfish?

Jellyfish do not have a central nervous system.

Squids which belongs to Cephalopoda (class of Mollusca) have the most complex nervous system of the invertebrates. They have well-developed senses and large brains. So, they are considered as the most intelligent of the invertebrates.

Dolphins, on the other hand, are  regarded as one the most intelligent animal.

thymine. in rna, thymine is replace by uracil

rain is the best answer