External Features (Morphology)

You know striated muscles appeared for the first time in the arthropods during evolution. Muscles need endoskeletal parts for attachment. The cockroach does not have an endoskeleton comparable to that of a chordate. Do you know how this problem of attachment surfaces is solved in cockroach? 

How is overlapping of insects is prevented in diurnal insects?

How can you identify a male and female cockroaches? Explain it describing the chief features of the external and internal genitalia

If 20% ommatidia are damaged in each compound eye, a diurnal insect can see only 80% of the visual field. Do you agree with the statement? If so explain.

How is each tripod of cockroach formed during locomotion?

What makes the articular membrane flexible? 

What are the mouthparts of cockroach are called biting and chewing type?

Distinguish between the apposition image and the superposition image.

Describe the abdomen of a cockroach.

Describe the structure of the head of a cockroach.

Draw a neat and labelled diagram of an ommatidium.

Describe the structure of an ommatidium and label its parts.

If the mesothoracic wings in the cockroach are removed do you think it can still fly? If so give reasons?

Of the following feature- antennae, mandibles, maxillae, legs and wings which do you think is taxonomically significant when we think of insects such as cockroach?

Why do insects moult in the early part of their life?

 List out the characters that help in understanding the difference between a male and female Cockroach.

Which part of the ommatidium constitutes the dioptric region?

Why is the brain called the principal sensory centre in cockroach?

Which of the abdominal ganglia is largest and why?

 How is the ommatidia of cockroach different from that of diurnal insects.