Questions: In general, what happens to the number of offspring as parental investment per offspring increases?

The answer is the third one: The number of offspring goes down.

Explanation:

• The number of offspring stays the same: This option is generally incorrect because, in biological terms, there is often a trade-off between the quantity and quality of offspring. As parental investment per offspring increases, resources such as time, energy, and care are directed more towards each individual offspring, which typically results in fewer offspring being produced overall.

• The number of offspring goes up: This option is incorrect because increasing parental investment per offspring usually means that parents have fewer resources available to produce a larger number of offspring. The focus is on ensuring the survival and success of each offspring rather than increasing the total number.

• The number of offspring goes down: This is the correct answer. In many species, when parents invest more resources into each offspring, they tend to produce fewer offspring. This is because the resources (time, energy, food, protection, etc.) are limited, and investing more in each offspring means there are fewer resources available to produce additional offspring.

Summary: In general, as parental investment per offspring increases, the number of offspring tends to decrease due to the trade-off between the quantity and quality of offspring.