The correct option is (c) 1 and 3 only.
Explanation
Redworms (specifically species like Eisenia fetida) are earthworms utilized in vermicomposting to convert organic waste into nutrient-rich manure. Their anatomical and physiological features are specialized for the decomposition of soft organic matter.
Statement 1 is Correct:
Redworms have a very high metabolic rate and feeding capacity. Under optimal conditions, a redworm can consume an amount of food roughly equivalent to its own body weight in a single day. This efficiency makes them highly effective for composting.
Statement 2 is Incorrect:
Redworms do not possess teeth. Consequently, they cannot chew tough or hard organic matter such as bones, hard shells, or woody stems. They rely on the food being soft or partially decomposed by microorganisms before consumption.
Statement 3 is Correct:
To process food without teeth, redworms possess a specialized muscular structure in their digestive tract called a gizzard. The gizzard grinds the food. In vermicomposting, gritty substances like powdered eggshells or sand are often added to the waste to assist the gizzard in pulverizing the food effectively.
Key Takeaway:
Redworms are toothless detritivores that utilize a muscular gizzard to grind food and are capable of consuming organic waste equal to their body weight daily.