Cockroach Test- Zoology, Class 11 Solved MCQs

• Correct Answer: B - Periplaneta americana

• Periplaneta americana: This is the scientific name for the American cockroach, one of the most common species of cockroaches found worldwide.


• Glossina palpalis: This is the scientific name for the tsetse fly, not a cockroach.


• Musca nebulo: This is the scientific name for a type of fly, not a cockroach.


• Apis indica: This is the scientific name for the Indian honeybee, not a cockroach.

• The correct zoological name for a cockroach is Periplaneta americana, which is option B in the given choices.


• Knowing the scientific name of an organism helps in accurately identifying and classifying it in the animal kingdom.

• Segmented body: Insects have a segmented body with three distinct regions: head, thorax, and abdomen. This segmentation allows for flexibility and movement.



• Chitin in body wall: The body wall of insects is made up of a tough, waterproof substance called chitin. This provides protection and support for the insect's body.



• Three pair of legs: Insects have three pairs of legs, which are attached to the thorax. These legs are used for walking, jumping, climbing, and other forms of locomotion.



• One pair compound eyes: Insects typically have one pair of compound eyes, which are made up of multiple individual lenses. These eyes provide insects with a wide field of vision and are well-suited for detecting movement.

Among these features, the presence of three pairs of legs is a diagnostic feature of insects. This characteristic sets them apart from other arthropods and helps in their classification.

• Periplaneta americana: Also known as the American cockroach, it is one of the most common cockroach species found in India. It is a large cockroach with a reddish-brown color and can be found in various habitats.


• Blatta orientalis: Commonly known as the Oriental cockroach, it is another prevalent cockroach species in India. It is dark brown to black in color and prefers damp and dark environments.

• Option A: Periplaneta americana and Blatta indica - Incorrect


• Option B: Periplaneta indica and Blatta orientalis - Incorrect


• Option C: Periplaneta orientalis and Blatta americana - Incorrect


• Option D: Periplaneta americana and Blatta orientalis - Correct

The correct answer is option D, which states that the two common Indian cockroaches are Periplaneta americana and Blatta orientalis. These two species are frequently found in various parts of India and are known for their adaptability to different environments.

• Joined Appendages: Insects in the group Insecta have appendages that are joined to their bodies, allowing them to perform various functions such as walking, flying, and feeding.



• 3 Pair of Jointed Legs: One of the key characteristics of insects in the group Insecta is that they have three pairs of jointed legs. These legs are used for locomotion, grasping, and other activities.



• Chitinous Exoskeleton: Another characteristic of group Insecta is the presence of a chitinous exoskeleton. This tough outer covering provides protection and support to the insect's body.



• Compound Eyes: Insects in the group Insecta typically have compound eyes, which are made up of multiple individual lenses. These eyes allow insects to detect movement and see a wide field of view.

• A: Linneous


• B: K.N. Bahel


• C: Bermister


• D: D. Gir

• Periplaneta is the genus of cockroaches, and the scientist who gave this name is Bermister.


• Bermister is credited with naming and classifying various species of cockroaches within the Periplaneta genus.


• Linneous is known for his work in taxonomy and binomial nomenclature, but he did not specifically name the Periplaneta genus.


• K.N. Bahel and D. Gir are not associated with the naming of the Periplaneta genus.

• Pleuron: Tergum is joined on the sides by pleuron, which is a lateral plate of the exoskeleton in arthropods. It acts as a protective covering for the body segments.

• Sternum: Sternum is not directly related to the joining of tergum on the sides. It is a flat bone located in the center of the chest.


• Alimentary canal: The alimentary canal is the digestive tract of an organism and is not involved in the connection of tergum on the sides.


• Muscles: While muscles play a role in the movement of the exoskeleton, they are not directly responsible for joining the tergum on the sides.

Therefore, the correct answer is A: Pleuron, as it is the lateral plate that joins the tergum on the sides.

• Plate situated between the eyes and passing below that on the head of a cockroach: This structure is known as the Fron.


• Vertex: The vertex is the uppermost point of the head and is not the plate situated between the eyes.


• Epicranium: The epicranium refers to the dorsal part of the head capsule and does not specifically denote the plate between the eyes.


• Gena: The gena is the part of the head that is on the side of the head and does not refer to the plate between the eyes.

Therefore, the correct answer is Fron, which is the plate situated between the eyes and passing below that on the head of a cockroach.

• Pleuron: Pleuron is the side plate of the exoskeleton of an insect, not the dorsal plate found on the abdomen of a cockroach.



• Sternum: Sternum is the ventral plate of the exoskeleton, not the dorsal plate found on the abdomen of a cockroach.



• Tergum: Tergum is the dorsal plate of the exoskeleton found on the abdomen of insects like cockroaches. It provides protection and support to the abdomen.



• Vertex: Vertex is the upper surface of an insect's head, not the dorsal plate found on the abdomen of a cockroach.

• Outer border of tergum: This refers to the outer edge of the dorsal plate of the exoskeleton in a cockroach.


• Bends downwards: The outer border of the tergum curves downward towards the ventral side of the cockroach's body.


• Attaches with Pleura: The pleura in insects are the lateral extensions of the tergum that connect it to the sternum, forming the side walls of the thorax.


• Function: This attachment with the pleura provides structural support and flexibility to the exoskeleton, allowing for movement and protection of internal organs.

• Structure: The mandibles of a cockroach are short and have grinding teeth.



• Function: These short mandibles with grinding teeth help the cockroach to chew and grind its food into smaller pieces before ingestion.



• Adaptation: The structure of the mandibles is adapted to the cockroach's diet, which mainly consists of plant material, decaying organic matter, and sometimes other insects.



• Efficiency: The grinding teeth on the mandibles help in breaking down tough plant fibers and other materials, making it easier for the cockroach to digest its food.



• Evolutionary Advantage: The short mandibles with grinding teeth provide the cockroach with an evolutionary advantage by allowing it to efficiently feed on a variety of food sources in its environment.

• Head of Cockroach: The head of a cockroach consists of several parts, including the hypopharynx.


• Hypopharynx: This is the part of the cockroach's head that is responsible for functions such as feeding and drinking.


• Position: The hypopharynx is located in the lower part of the head, near the mouthparts.


• Function: It helps in the manipulation of food and liquids during feeding.


• Identification: When identifying the head of a cockroach, the hypopharynx plays a crucial role in distinguishing it from other insects.


• Answer: Therefore, the correct answer to the question is Hypognathus.

• Number of sternum in a female cockroach abdomen: Female cockroaches have 7 sternum present at their abdomen.


• Identification: The sternum is a series of sclerites or plates on the ventral side of the abdomen of the cockroach.


• Function: The sternum provides support and protection to the internal organs of the cockroach.


• Characteristic feature: The presence of sternum helps in identifying the gender of the cockroach, as females have 7 sternum while males have 8 sternum in their abdomen.


• Importance: Knowing the number of sternum can help in differentiating between male and female cockroaches.

• Maxilla: The maxilla is not the tongue-like structure in Periplaneta.


• Hypopharynx: The hypopharynx in Periplaneta is a tongue-like structure that functions in the manipulation of food during feeding.


• Labium: The labium is not the tongue-like structure in Periplaneta.


• Labrum: The labrum is not the tongue-like structure in Periplaneta.

Therefore, the correct answer is Hypopharynx. The hypopharynx in Periplaneta serves a similar function to a tongue in other organisms and aids in the ingestion of food.

• Labium: The labium is the structure known as the lower lip of a cockroach. It is located below the mouthparts and is responsible for manipulating and consuming food.

• Food Manipulation: The labium helps in manipulating food and guiding it towards the mouthparts for ingestion.


• Protection: It also provides protection to the mouthparts and aids in the feeding process.

• Essential for Feeding: The labium plays a crucial role in the feeding process of cockroaches, allowing them to consume and digest their food effectively.


• Structural Support: It provides structural support to the mouthparts and helps in their coordination during feeding activities.

• Protection: Cockroach wings serve as a protective covering for their body, shielding them from external threats such as predators and harsh environmental conditions.



• Camouflage: The wings of cockroaches also help them blend into their surroundings, providing them with a form of camouflage to avoid detection by predators.



• Thermoregulation: The wings play a role in regulating the body temperature of cockroaches, helping them adapt to different environments and maintain their metabolic functions.



• Balance and Stability: Wings aid in the balance and stability of cockroaches while they move around, climb surfaces, and navigate their environment effectively.



• Communication: Cockroaches use their wings to produce sounds and communicate with other members of their species, especially during mating rituals and territorial disputes.

Overall, the wings of cockroaches are essential for their survival and reproductive success, playing a crucial role in their daily activities and interactions within their ecosystem.

• Wings: Periplaneta americana has well-developed wings, while Blata orientalis has wings absent.

• Periplaneta americana: This species of cockroach, also known as the American cockroach, has well-developed wings that cover its body. These wings enable it to fly short distances.


• Blata orientalis: In contrast, Blata orientalis, also known as the Oriental cockroach, does not have wings. This species is flightless and relies on crawling to move around.

• Therefore, the main difference between Periplaneta americana and Blata orientalis lies in the presence or absence of wings, with Periplaneta americana having well-developed wings and Blata orientalis lacking wings altogether.

• Explanation:


• The cockroach leg is divided into several segments, each serving a specific function in the movement and stability of the insect.


• Identification of Segments:


• Each cockroach leg consists of five segments, which are:




• Coxa


• Trochanter


• Femur


• Tibia


• Tarsus




• Function of Each Segment:


• These segments work together to allow the cockroach to move efficiently and effectively.


• Each segment has its own unique structure and function, contributing to the overall movement of the insect.


• Conclusion:


• Therefore, the correct answer to the question is 5 segments in a cockroach leg.

• Blatta: Blatta, commonly known as cockroaches, have undeveloped wings in their nymph stage. These wings gradually develop as they molt and grow.


• Housefly, Mosquito, and Cockroach: Houseflies and mosquitoes do not have undeveloped wings; they have fully developed wings used for flight. Cockroaches, on the other hand, have wings that are not functional for flight and are usually hidden under wing covers.


• Importance of Wings: Wings play a crucial role in the survival and reproduction of insects. They help insects navigate their environment, escape predators, and find mates.


• Evolutionary Significance: The presence or absence of wings in insects can provide valuable insights into their evolutionary history and adaptation to different environments.

• Similarity between pseudopodia of Amoeba and legs of cockroach:




• Both are used for movement in their respective organisms.


• Pseudopodia in Amoeba are temporary projections of the cell membrane and cytoplasm used for locomotion and capturing food.


• Legs of cockroach are used for walking and running, aiding in the movement of the organism.

• Pretarsus: Plantulae are found in the pretarsus of a cockroach. The pretarsus is the last segment of the leg and plays a role in gripping surfaces.



• Femur: Plantulae are not found in the femur of a cockroach. The femur is the third segment of the leg and is involved in locomotion.



• Trochanter: Plantulae are not found in the trochanter of a cockroach. The trochanter is the second segment of the leg and allows for movement.



• Coxa: Plantulae are not found in the coxa of a cockroach. The coxa is the first segment of the leg and connects the leg to the body.

Therefore, the correct answer is option A: Pretarsus. Plantulae are specialized structures found in the pretarsus of cockroaches that help them cling to different surfaces.

• Coxa: The most swollen segment in the leg of a cockroach is the coxa. It is the basal segment of the leg that connects to the body.

• The coxa is the largest and most prominent segment in the leg of a cockroach, providing support and stability for movement.


• It is attached to the body and serves as the main connection point between the body and the rest of the leg segments.


• The coxa also houses important muscles and nerves that control the movement of the leg.


• Due to its size and function, the coxa is easily distinguishable as the most swollen segment in the leg of a cockroach.

• Locomotion: The arolium is a specialized structure found at the tip of the tarsus in cockroaches. It helps in providing grip and traction during locomotion. Cockroaches use their arolium to cling onto various surfaces and move efficiently.

• Mobility: The arolium plays a crucial role in the mobility of cockroaches by aiding in their movement across different surfaces.


• Adaptation: The presence of arolium enables cockroaches to navigate through diverse environments and habitats, showcasing their adaptability.


• Survival: The efficient grip provided by the arolium helps cockroaches in escaping predators and finding food sources, contributing to their survival in the ecosystem.

• Overall, the arolium in cockroaches serves a vital function in their locomotion, aiding in their mobility, adaptation, and survival in their environment.

• Antennae: The antennae of male cockroaches are typically longer and more pronounced compared to female cockroaches. This is a key physical characteristic used to differentiate between the two genders.



• Mandibles: Male cockroaches usually have larger and more powerful mandibles than female cockroaches. These mouthparts are used for feeding and defense, and their size can help in distinguishing between male and female cockroaches.



• Anal cerci: The anal cerci, which are sensory appendages located at the end of the abdomen, can also be used to differentiate between male and female cockroaches. The size and shape of these structures may vary between the two genders.



• Anal style: The anal style, another structure located at the tip of the abdomen, can be used to distinguish between male and female cockroaches. This structure may have different shapes or sizes in males and females.

Answer: d. Anal style

• Male Cockroach: Male cockroaches have anal styles, which are specialized structures used during the mating process.


• Female Cockroach: Female cockroaches do not have anal styles, only males possess this feature.


• Function: The anal styles in male cockroaches play a crucial role in mating, as they are used to grasp the female during copulation.


• Distinctive Feature: The presence of anal styles is a key characteristic that helps distinguish male cockroaches from females.

Based on the information provided, the correct answer is C: Male cockroach.

• Hydra: Hydra does not have well-defined body segments. It is a simple, tubular organism without distinct body segments.



• Taenia: Taenia, also known as tapeworm, is a flatworm that does not have distinct body segments. It has a long, ribbon-like body without clear segmentation.



• Earthworm: Earthworms have well-marked body segments called annuli. These segments are visible externally and help in movement and locomotion.



• Cockroach: Cockroaches have well-defined body segments, including head, thorax, and abdomen. These segments are clearly differentiated and help in the movement and functioning of the organism.

• Among the options given, the organism with definite and well-marked body segments is the cockroach.


• Body segmentation is an important characteristic in different organisms and plays a crucial role in their physiology and behavior.

• On legs: Audioreceptors are not located on the legs of cockroaches. Legs are primarily used for locomotion and support.


• Antenna: Cockroaches have sensory hairs on their antennae that help them detect vibrations in the air, but these are not specifically for hearing.


• Sensory receptor: While cockroaches have sensory receptors throughout their bodies, the specific audioreceptors are not located on these general sensory receptors.


• Anal cerci: The audioreceptors in cockroaches are actually located on the anal cerci, which are sensory appendages near the abdomen. These cerci help them detect air movements and vibrations, which are important for detecting predators and other dangers in their environment.

Therefore, the correct location of audioreceptors in cockroaches is on their anal cerci.

• Gynovalvular plates: These are structures found in female cockroaches and are responsible for covering the genital opening.


• Modification of 7th sternum: The gynovalvular plates in female cockroaches are actually modified from the 7th sternum, not the 7th tergum.


• Function: These plates play a crucial role in reproduction by protecting the genitalia and facilitating the process of oviposition.


• Location: The 7th sternum is a ventral part of the abdomen of the cockroach, where these plates are specifically modified to serve their reproductive function.


• Importance: Understanding the anatomy and modifications of gynovalvular plates is important for studying the reproductive biology and behavior of female cockroaches.

• Location: Stink glands, also known as scent glands, are found in various animals and are used for communication, defense, or marking territory.


• Function: These glands produce odorous substances that are released by the animal when needed.


• In both genders: Stink glands can be found in both male and female animals.


• Species with stink glands: Some common examples of animals with stink glands include skunks, beavers, and some species of rodents.


• Usage: These glands play a crucial role in the survival and social interactions of animals in the wild.

• Composition: The exoskeleton of a cockroach is primarily made up of chitin.


• Chitin: Chitin is a tough, protective polysaccharide that provides structure and support to the exoskeleton.


• Function: The exoskeleton protects the cockroach's body, prevents dehydration, and provides attachment sites for muscles.


• Growth: As the cockroach grows, it molts its exoskeleton and forms a new larger one in a process called ecdysis.


• Strength: Chitin is a strong material that allows the exoskeleton to withstand physical stresses and protect the cockroach from predators.

Therefore, the exoskeleton of a cockroach is primarily made up of chitin, which provides strength, protection, and support to the insect's body.

• Composition: The exoskeleton of cockroach and other insects is primarily made up of Chitin.


• Chitin: Chitin is a tough, protective polysaccharide that provides structural support to the exoskeleton.


• Function: The exoskeleton made of chitin helps in protecting the insect's body, providing support for muscle attachment, and preventing desiccation.


• Structure: The exoskeleton is composed of multiple layers, including a thick outer layer called the cuticle.


• Renewal: Insects periodically shed their exoskeleton in a process called molting to accommodate growth.

Therefore, the exoskeleton of cockroach and other insects is primarily composed of chitin, which plays a crucial role in providing structural support and protection to their bodies.