The Placement of the Phylum Platyhelminthes in the Phylogenetic Tree

question 32

Multiple Choice

The placement of the phylum Platyhelminthes in the phylogenetic tree differs between a morphologically based phylogeny and a molecular based phylogeny.How do scientists best differentiate the interpretation based on molecular phylogeny?

• A)Modern Platyhelminthes do not have a coelom but did originate from an ancestor that had one.
• B)The Platyhelminthes clade separated from other clades before coeloms evolved and consequently Platyhelminthes have never had a coelom.
• C)Platyhelminthes originated from ancestors with a coelom and have retained it to the present time.
• D)Platyhelminthes evolved from an ancestor without a coelom but developed one during the course of their evolution.
• E)Some Platyhelminthes have a coelom but others do not and it is difficult to conclude anything about its evolution within the cladE.

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Definitions:

Active Euthanasia

The practice of intentionally ending a life to relieve pain and suffering, typically through the administration of lethal substances.

Passive Euthanasia

The act of withholding or withdrawing medical treatments or interventions, allowing a person to die naturally, often discussed in the context of end-of-life care.

Significant Moral Difference

A substantial distinction, based on ethical or moral grounds, that affects how situations or actions are evaluated.

Prima Facie Duty

A duty that is apparent and obligatory until proven otherwise, often used in ethical discussions to describe actions that appear morally necessary at first glance.