Which of the following is true about the life cycle of parasites?

The statement that all parasites require a host for growth and reproduction is accurate because parasites are organisms that depend on a host for their survival, nutrition, and reproductive processes. Unlike some microbes that can thrive in environments without a host, parasites have evolved to rely on their hosts for the resources they need to grow and propagate. This dependency characterizes their life cycle, which typically includes various stages that may involve different hosts or developmental forms.

In contrast, the idea that parasites can survive outside the host indefinitely is misleading, as most parasites have limited timeframes outside their hosts and typically require specific conditions to survive. Additionally, while some parasites can cause minimal harm to their hosts, many are indeed pathogenic and can lead to diseases or health issues. The notion that parasites cannot develop resistance to treatments is also incorrect; instances of resistance to antiparasitic medications have been documented, highlighting the adaptability of these organisms. Thus, the requirement of a host for their lifecycle is a fundamental aspect of parasitic biology.