Answer: The noun clause in the sentence "Do whatever task needs to be done" is "whatever task needs to be done" and its function is direct object.
Explanation: Noun clauses are a type of dependent clauses, clauses that cannot stand by themselves because they do not present complete ideas. Unlike adjectival clauses and adverbial clauses, noun clauses act as nouns and can be introduced by different relative pronouns, such as "whoever", "what", "why" and "whatever". The noun clause in the sentence provided is "whatever task needs to be done" has been introduced by the relative pronoun "whatever". Furthermore, this clause is acting as a noun and as a direct object since it is functioning as the recipient of the transitive verb "do", which is preceding the noun clause.
