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.
This is True . the reabsorption through the proximal tubule is obligatory 80% whereas water reabsorption through distal tubule is facultative but mostly through collector tubules 15 % ( under the action of aldosteron and antidiuretic hormone).
The answer is; B
Meristem cells are totipotent meaning they can differentiate to any type of plant cells. Therefore they can produce a variety of plant type depending on epigenetic. However, tissue culture is derived from already differentiated cells. Therefore these cells are already determined and can only produce cell type of that plant from which they were derived.