Question

Cockroaches and house flies are not involved in the parasite's life cycle, but are merely carriers; they are referred to as ___ disease vectors.

Option 1: Mechanical
Option 2: Biological
Option 3: Vector-borne
Option 4: Intermediate

Answer 1

Cockroaches and house flies are referred to as mechanical vectors because they transfer pathogens without being part of the parasite's life cycle. Unlike biological vectors like mosquitoes in malaria, mechanical vectors carry pathogens on their bodies.

Step-by-step explanation:

Cockroaches and house flies that carry pathogens from one host to another without being infected themselves are referred to as mechanical vectors. They physically transport the pathogens on their body parts, as opposed to biological vectors which are part of the pathogen's life cycle. For instance, mosquitoes are biological vectors for malaria as they not only carry the parasite but also provide an environment for part of the parasite's lifecycle to occur. On the other hand, when a house fly lands on contaminated food and later comes into contact with a human food source, they can transfer disease-causing organisms without becoming infected themselves, exemplifying a mechanical vector's role in disease transmission.