Answer: Option A
Explanation:
A tunicate is marine invertebrate animal which is a part of chordates. They have notochords and dorsal nerve chord. The subphylum of the organism is called as Urochordata.
The adult urochordates lack notochord but the larval stage of the urochordates have notochord. This is because it helps in swimming of the organism which is required only at the larval stage.
The adult stage of the tunicates is sessile and they do not swim so they do not require notochord.
2 and 3 are too similar to distinguish because they both are saying it's been back up on several different accounts but 3 seems like a more solid answer go with 3
It was the famous Theodor Escherich who is a famous German bacteriologist that discovered the E. coli and was also known for his research in the area of protein synthesis. In addition to that, Theodor Escherich discovered the bacteria type when he examined its samples from a patient suffering from gastroenteritis.
The independent variable controls the dependent variables.