Final answer:
The statement is b) false. Autotrophs, especially photoautotrophs that rely on photosynthesis, would not be more abundant without photosynthesis as it is a vital process for their energy production and the energy flow within ecosystems.
Step-by-step explanation:
The statement 'Without photosynthesis, autotrophs would be more abundant' is b) false. Autotrophs, such as photoautotrophs and chemoautotrophs, are crucial for ecosystems because they are the primary producers of food and oxygen, forming the base of the food chain.
Without photosynthesis, the energy flow from the sun into the ecosystems would cease, significantly reducing the abundance of autotrophs, as photoautotrophs—like plants, algae, and cyanobacteria—rely heavily on the process to produce energy.
Chemoautotrophs, while not dependent on light, are far less abundant and would not be able to compensate for the loss of photoautotrophs.