Question

Number of legs found on the thorax of cockroach is?
A. 2
B. 4
C. 6
D. 8

Answer 1

Hint: The bodies of cockroaches have three primary regions. These are the head, the thorax, and the abdomen. They possess three pairs of jointed legs, one pair of antennae, and a rigid exoskeleton. Most cockroaches include three joints on each leg, which means they have 18 knees. The metathoracic legs are encountered at the back of the thorax and they help the insect to move forward.

Complete answer:
Let's understand the basic anatomy of a cockroach. Its body is divided into three segments: head, thorax, and abdomen.

Cockroaches have a long pair of antennae which are used to pick up smells and vibrations. The antennae are connected to the head, which also includes the brain. They have strong mouthparts for scraping and chewing food. They also have compound eyes. They have poor vision and dislike light, which is why maximum species are nocturnal.

After the head comes to the thorax which includes three pairs of legs – cockroaches have six legs in total. Along with these, they have two pairs of wings. Additionally, they possess a plate behind the head called the pronotum. It is significant because that is where many species have differentiating markings. Most adult cockroaches have wings, but only a limited species fly. However, cockroaches can crawl at speeds of up to 3 miles per hour. They are also able to traverse walls and ceilings because their legs have short, spiky protrusions that stick to surfaces.

The abdomen is the last piece, and it contains reproductive organs. At the back of the abdomen, there are two short protrusions known as cerci. They function like rear antennae that are connected to the roach's legs by the abdominal nerve ganglia. This allows their legs to move when vibrations are sensed, often before their brain even processes a threat. That is why it is hard to sneak up on a roach.

So the correct answer is option C- '6'.

Note: Cockroaches are insects of the order Blattodea, which also comprises termites. About 30 cockroach species out of 4,600 are associated with human habitats and about five species are well known as pests.