Lamprey larvae resembling Amphioxus demoristrates

Options

A. retrogressive metamorphosis
B. progressive metamorphosis
C. neoteny
D. adaptive convergence

Answer

To analyze the question regarding the resemblance of Lamprey larvae to Amphioxus, we can break down the solution into the following steps:

### Step 1: Understand the Organisms
- **Lamprey**: A jawless fish that has a larval stage known as ammocoete.
- **Amphioxus**: A marine organism that is a representative of the cephalochordates, known for its simple body structure and is often used to study vertebrate evolution.

### Step 2: Identify the Developmental Stages
- Both Lamprey and Amphioxus go through distinct developmental stages: egg, larva, and adult.
- In Amphioxus, the larval stage is more advanced in terms of structure compared to the adult stage.

### Step 3: Define Retrogressive and Progressive Metamorphosis
- **Retrogressive Metamorphosis**: This is when the larval stage is more advanced than the adult stage. In this case, the adult form becomes less modified and often less mobile.
- **Progressive Metamorphosis**: This is when the larval stage develops into a more complex adult form, which is the case in Amphioxus.

### Step 4: Analyze the Options
- The question presents several options regarding the characteristics of Lamprey larvae in relation to Amphioxus.
- The correct option should reflect the type of metamorphosis that is observed in these organisms.

### Step 5: Conclusion
- The correct answer is that Lamprey larvae demonstrate **Progressive Metamorphosis**, as they develop from a larval stage into a more complex adult form, similar to Amphioxus.

### Final Answer
Lamprey larvae resembling Amphioxus demonstrate **Progressive Metamorphosis**.

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