Question
Biology Question on Structural Organisation of Animals and plants
Which of the following is correctly stated as it happens in the common cockroach ?
A
Malpighian tubules are excretory organs projecting out from the colon.
B
Oxygen is transported by haemoglobin in blood.
C
Nitrogenous excretory product is urea.
D
The food is grinded by mandibles and gizzard.
Answer
The food is grinded by mandibles and gizzard.
Explanation
Solution
Mouth parts of cockroach contain two mandibles, which bears teeth. When both the mandibles work simultaneously in a horizontal plane, the food matter is cut and masticated into fine and smaller pieces. Gizzard is a part of alimentary canal. It bears six muscular folds which are covered by chitinous conical plates, the teeth, used for grinding the food.