Massachusetts Comprehensive Assessment System (MCAS) Biology Practice Test

How do lobsters grow new claws?

1. Through regeneration of existing cells

2. By mitotic cell division

3. By cellular differentiation

4. Through a process of clonal expansion

The correct answer is: By mitotic cell division

The process by which lobsters grow new claws primarily relies on regeneration. This regenerative ability allows lobsters to replace lost appendages, such as claws, through the regeneration of existing cells. When a lobster loses a claw, a blastema forms at the site of the injury, where specialized cells begin to proliferate and differentiate. This regeneration process involves the growth of new tissue and the gradual formation of a new claw, although not through clonal expansion or mitotic cell division alone. Instead, it's characterized by a combination of cellular processes, but not exclusively reliant on mitosis as the main mechanism. Therefore, the correct understanding of how lobsters regrow claws centers around their unique regenerative capabilities, emphasizing the remarkable nature of their biology in regenerating limbs rather than relying solely on cell division methods like cloning or standard mitosis.