If an Eight-Cell Sea Urchin Embryo Is Bisected Horizontally

question 55

Multiple Choice

If an eight-cell sea urchin embryo is bisected horizontally,

• A) both halves develop into normal, but small, larvae.
• B) the top cells remain embryonic, while the bottom cells produce an abnormal larva.
• C) the top cells remain embryonic, while the bottom cells produce a small, but normal, larva.
• D) the bottom cells remain embryonic, while the top cells produce an abnormal larva.
• E) the bottom cells remain embryonic, while the top cells produce a small, but normal, larva.

Understand mechanisms of reproductive isolation including sexual isolation and hybrid viability.

Distinguish between allopolyploidy and autopolyploidy and their roles in speciation.

Analyze the differences and issues associated with the phylogenetic and biological species concepts.

Understand the process and implications of reinforcement in speciation.

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