生活史：练习题

Marine mammals, such as whales, are described as having a simple life cycle. Which of the following is a characteristic of this type of life cycle?

In species with a complex life cycle, such as crabs, what is the ecological importance of the larval stage being planktonic while the adult is benthic?

In terms of parental investment, which of the following sequences correctly ranks these marine organisms from lowest to highest energy spent per individual offspring?

Which of the following terms correctly identifies a marine organism that has limited motility and primarily drifts in water currents?

Which of the following correctly relates the type of fertilisation to the level of parental investment in marine species?

State two key differences between a simple life cycle and a complex life cycle in marine organisms.

Explain why the life cycle of a shrimp is considered complex while that of a whale is considered simple.

Discuss why internal fertilisation combined with high parental investment in sharks leads to a higher survival rate for individual offspring compared to the strategy employed by tuna.

Marine organisms often have complex life cycles with distinct stages. Some adult marine organisms are sessile.

(a) Describe the meaning of the term sessile.

(b) State whether a larval stage is a feature of a simple or a complex life cycle.

(c) Many sessile organisms have a motile larval stage. Explain two advantages of having a motile larval stage in their life cycle.

Many marine crustaceans, such as crabs and lobsters, have complex life cycles that include multiple distinct stages.

(a) Describe the process of metamorphosis and its role in a complex life cycle.

(b) Many adult crustaceans are non-sessile, yet they still produce planktonic larvae. Suggest two advantages of a planktonic larval stage for a non-sessile adult species.

(c) Contrast the life cycle of a crustacean with the simple life cycle of a marine mammal.