Sponges and Ctenophores Have Both Been Proposed as Basal Metazoans

question 19

Multiple Choice

Sponges and ctenophores have both been proposed as basal metazoans. Which of the following types of data support the idea that sponges are the basal group?

• A) sequences of cadherin genes, cleavage type, structure of collar cells, and bilateral symmetry of adults
• B) sequences of collagen genes, bilateral symmetry of adults, cleavage type, and fossil steroids
• C) recent phylogenomic evidence, fossil steroid evidence, molecular clock, lack of tissues in sponges, and structure of collar cells
• D) structure of collar cells, bilateral symmetry of larvae, sequences of cadherin genes, and molecular clock

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