AP Inter 1st Year Zoology Important Questions Chapter 7 Type Study of Periplaneta Americana (Cockroach)

Students get through AP Inter 1st Year Zoology Important Questions 7th Lesson Type Study of Periplaneta Americana (Cockroach) which are most likely to be asked in the exam.

AP Inter 1st Year Zoology Important Questions 7th Lesson Type Study of Periplaneta Americana (Cockroach)

Very Short Answer Questions

Question 1.
Why do you call cockroach a pest?
Answer:

1. Cockroach is called a pest because it contaminates the food with its excreta.
2. It transmits a number of bacterial diseases. It is a mechanical carrier of disease-causing organisms.

Question 2.
Name the terga of thoracic ..segments of coekroadi?
Answer:

1. Terga are the dorsal plates of exoskeleton of cockroach.
2. The thoracic terga are
   (i) Pronotum- tergum of prothorax.
   (ii) Mesonotum- tergum of mesothorax.
   (ii) NJetanotum- tergum of metathorax.

Question 3.
What are the structures with which cockroach walks mi smooth surfaces and on rough surfaces respectively?
Answer:

1. Cockroach uses plantulae to walk on smooth surface.
2. It uses claws and arolium to walk on rough surfaces.

Question 4.
Name the chitinous tubes that support the wings of cockroach?
Answer:

1. Hollow Veins (or) nerves support the wings of cockroach.
2. They are formed by a network of fine sclerotised tubes.

Question 5.
What is tegmen? What is its funciton?
Answer:

1. The thick, opaque, leathery and flightless forewings of cockroach are called tegmen.
2. They donot help in flight but cover and protect the hind wings when they are not in use.

Question 6.
Why is the head in cockroach called hypognathus? |TS JVM 7]
Answer:

1. The head is kept at right angles to the remaining body, with the mouth parts directed downwards.
2. This condition is called hypognathus (Hypo-below, gnathus – jaws).

Question 7.
How is tripod formed with reference to locomotion in cockroach?
Answer:

1. Cockroach forms two tripods while walking.
2. Each tripod is formed by foreleg and hind leg of one side and middle leg of the other side.

Question 8.
Name the muscles that help in elevating and depressing the wings of a cockroach?
Answer:

1. Elevation of the wing of cockroach is done by ’contraction of dorsoventral muscles’.
2. Depression of the wing is done by ‘contraction of dorso-longitudinal muscles and relaxation of ventral muscles’.

Question 9.
Name the different blood sinuses in cockroach?
Answer:
There are three blood sinuses in cockroach.

1. Pericardial haemocoel or dorsal sinus encloses 13 chambered heart.
2. Perivisceral haemocoel or middle sinus encloses the most of the viscera (largest sinus).
3. Perineural sinus or ventral sinus encloses the ventral nerve cord.

Question 10.
How are the fat bodies similar to the liver of the vertebrates?
Answer:

1. Fat bodies collect nitrogenous wastes and store them as uric acid.
2. The liver of vertebrates collect ammonia and converts into urea through ornithine cycle.
3. Both organs help in excretion.

Question 11.
What are the three regions of the alimentary canal in cockroach?
Answer:

1. Alimentary canal of cockroach extends from mouth to anus.
2. It is divided into 3 regions.

They are (a) Foregut(stomodaeum) (b) Midgut(mesenteron) (c) Hindgut (proctodaeum)

Question 12.
How many denticulate plates are present in the gizzard of cockroach.
Answer:
The chitinous inner lining of the gizzard contains six powerful teeths which are efficient in grinding.

Question 13.
Which part of the gut secretes the peritrophic membrane in cockroach?
Answer:
The funnel like stomodeal valve of gizzard (fore gut) secretes peritrophic membrane which enelops food bolus.

Question 14.
Which parts of cockroach help in locating the food?
Answer:
Food is located with the help of olfactory sensillae of antenna, labial palps and maxillary palps of the cockroach.

Question 15.
In which part of the gut of cockroach, wafer is reabsorbed?
Answer:

1. Water is reabsorbed by rectum of hindgut.
2. The inner walls of the rectum has six longitudinal chitinous folds, called ‘rectal papillae’ which help in the reabsorption of water from the undigested food.

Question 16.
Write the names of mouth parts in cockroach that help in biting and tasting the food.
Answer:

1. The mouth parts of cockroach that help to bite the food are mandibles.
2. The mouth parts that help in tasting are gustatory sensillae present on inner surface of labrum.

Question 17.
What arc alary muscles?
Answer:

1. Alary muscles are paired triangular muscles on the lateral side of the body cavity.
2. One pair of these muscles are present in each segment. They are attached to pericardial septum on one side and to the terga on the other.
3. Contraction of alary muscles help in circulation of blood.

Question 18.
What is haemocoel?
Answer:

1. The functional body cavity of an arthropod, which is filled with blood is called Haemocoel.
2. It is formed by blastocoeT and true coelom.

Question 19.
The three sinuses in a cockroach are not equal in size. Why?
Answer:

1. The middle sinus is very large, because it encloses most of the visceral organs.
2. The dorsal sinus is small, because it encloses only heart. Hence called pericardial sinus.
3. The ventral sinus is small. It encloses only nerve cord and hence called perineural sinus.
4. They are not equal in size because all the three sinus enclose different organs of different sizes.

Question 20.
Why is the blood ofPeriplaneta called haemolymph?
Answer:

1. Blood of Periplaneta is colourless due to the absence of respiratory pigment.
2. It flows freely within the haemocoel. It serves the functions of both the blood and lymph. Hence it is described as haemolymph.

Question 21.
What is the function of haemocytes found in the blood of Periplaneta?
Answer:

1. Haemocytes are large blood corpuscles of Periplaneta. They are phagocytic.
2. The haemocytes ingest harmful bacteria and disintegrating tissue parts.

Question 22.
Why does not the blood of Periplaneta help in respiration?
Answer:

1. Blood of Periplaneta is colourless due to the’absence of respiratory pigment’.
2. So, it cannot help in respiration.

Question 23.
Write important functions of blood in Periplaneta?
Answer:
Functions of blood in Periplaneta:

1. Blood absorbs the digested food from alimentary canal and distributes to other parts.
2. It collects nitrogenous wastes from various parts and transfers to excretory organs.
3. It protects the body by engulfing bacteria and damaged tissue.
4. It transports hormones to target organs.

Question 24.
The blood of periplaneta is not red. Which pigment do you think, is absent in it?
Answer:

1. The respiratory pigment which imparts red colour to blood is haemoglobin.
2. It is absent in the blood of periplaneta and so it plays no role in respiration.

Question 25.
How many spiracles are present in Cockroach? Mention their locations.
Answer:

1. There are ten pairs of spiracles (stigmata) in Cockroach.
2. The first two pairs are present in thorax, one pair in mesothorax and the other is metathorax.
3. The remaining 8 pairs are present in first 8 abdominal segment.

Question 26.
What are trichomes? Write their functions.
Answer:

1. Trichomes are small hair like structure present in spiracles.
2. They filter the dust particles during inspiration.

Question 27.
Why is the respiratory system of cockroach called polypneustic and holopneustic system?
Answer:

1. Polypneustic because the respiratory system of cockroach has more than 3 pairs spiracles.
2. Holopneustic because all the spiracles are functional.

Question 28.
Name the chitinous ring that encircles the spiracle of cockroach?
Answer:

1. Peritreme is the chitinous ring that encircles the valvular spiracles of cockroach.
2. It gives support to the spiracle.

Question 29.
What is in tima?
Answer:
Intima The wall of the trachea is made of three layers. The inner cuticular layer of tracheal wall is called intima. It is formed into a spiral thickening called taenidia. It is present in the respiratory (tracheal) system of cockroach.

Question 30.
Name the protein that lines the tracheole of the cockroach?
Answer:
Trachein is the protein that lines the tracheole of the cockroach.

Question 31.
During inspiration which spiracles are kept open and which are kept dosed?
Answer:
During inspiration, the thoracic spiracles are kept open and the abdominal spiracles are kept closed.

Question 32.
Which factors regulate the opening of the spiracles?
Answer:
Opening and closing of spiracles is influenced by the C02 tension in haemolymph and oxygen tension in the tracheae.

Question 33.
Inspiration in cockroach is a passive process and expiration is an active process. Justify?
Answer:

1. In inspiration of cockroach, the air is drawn in due to relaxation of muscles. So inspiration is a passive process. Energy is not used.
2. During expiration, the air is sent out by contraction of muscle. So expiration is an active process. Energy is used.

Question 34.
The nitrogenous wastes in Periplaneta are removed from the body through alimentary canal. Why?
Answer:

1. The nitrogenous wastes of excretion are sent out through the alimentary canal to conserve water. It is an adaptation for terrestrial organisms.
2. After water is completely reabsorbed in the last part of alimentary canal, dry uricacid is excreted through alimentary canal.

Question 35.
How does the cuticle of a cockroach help in excretion?
Answer:

1. Waste materials deposited on cuticle is elminated from time to time.
2. This process is called ecdysis.

Question 36.
How do fat bodies help in excretion?
Answer:
Fat bodies contain urate cells. These cells absorb and store uric acid. Thus fat bodies also play a role in excretion.

Question 37.
What is ‘storage excretion’?
Answer:
Urate cells are present in fat bodies of cockroach. They absorb and store uric acid through out life. This process is called storage excretion.

Question 38.
In which part of the alimentary canal of Periplancta more water is reabsorbed?
Answer:

1. In the ‘Rectum’ of the alimentary canal of cockroach more water is reabsorbed.
2. It contains six longitudinal folds called rectal papillae which reabsorb water from the undigested food.

Question 39.
List out the organs associated with excretion in periplaneta?
Answer:
The organs associated with excretory function are

1. Malpighian tubules
2. Fat bodies
3. Uricose glands
4. Nephrocytes
5. Cuticle.

Question 40.
Which part of Malpighian tubules extract water, salts and nitrogenous wastes from the haemolymph?
Answer:
“Glandular cells’ of the malpighian tubules extract water, salts and C02 and nitrogenous wastes from the haemolymph.

Question 41.
Which structure of cockroach acts as sensory and endocrine centre?
Answer:
Brain of cockroach acts as a sensory and an endocrine centre.

Question 42.
Distinguish between scolopidia and sensillae.
Answer:

Scolopidia	Sensillae
1) Scolopidia are the subcuticular units of mechano receptors of chordotonal organs. 2) These are present below the epidermis.	1) Sensillae are the units of cuticular receptors and chemo receptors. 2) These are present above the epidermis.

Question 43.
How is the ommatidium of cockroach different from that of u uiuriul Insect?
Answer:
1) Cockroach is a nocturnal insect. The retinulae are deep below the cone cells and crystalline cones. Retinal sheath is absent. Light rays from adjacent ommatidia overlap forming superposition image (blurred).

2) In diurnal insects like houseflies, the retinulae are in contact with conecells and crystalline cone. Retinal sheath surround the retinulae. The light rays from adjacent ommatidia do not overlap and form apposition image (Mosaic vision)

Question 44.
How many segmental ganglia are present on the ventral nerve cord of cockroach?
Answer:

1. ‘9’segmental ganglia are present on the ventral nerve cord of cockroach.
2. Three thoracic ganglia are present one in each throracic segment. In addition, 6 abdominal ganglia are present.
3. 1-4 abdominal segments have one ganglion and 5th ganglion is present in 6th segment.
4. 6th abdominal ganglian is present in the 7th segment.

Question 45.
Which of the abdominal ganglia is the largest and why?
Answer:

1. The last or the 6th abdominal ganglion is the largest and present in the 7th abdominal segment.
2. Because it is formed by the fusion of the ganglia of 7th, 8th, 9th and 10th abdominal segments.

Question 46.
Name the structural and functional unit of compound eye of cockroach, How many such units are present in a single compound eye?
Answer:

1. The structural and functional units of compound eye of cockroach is Ommatidium.
2. There are about 2000 ommatidia in a single compound eye.

Question 47.
Why is the brain called the principal sensory centre in cockroach?
Answer:
There are three lobes in brain of cockroach.

1. Protocerebrum receives sensory impulses from eyes.
2. Deutocerebrum receives sensory impulses from antennae.
3. Tritocerebrum receives sensory impulses from labrum.
   So brain is the principal sensory centre in cockroach.

Question 48.
Which parts of an ommatidium constitute dioptric region?
Answer:
Cornea and crystalline cone region of an ommatidium constitute ‘dioptrical’ or ‘focussing region’.

Question 49.
Distinguish between apposition image and superposition image,:
Answer:

Scolopidia	Sensillae
1) Scolopidia are the subcuticular units of mechano receptors of chordotonal organs. 2) These are present below the epidermis.	1) Sensillae are the units of cuticular receptors and chemo receptors. 2) These are present above the epidermis.

Question 50.
List out the characters that help in understanding the difference between male and female cockroaches.
Answer:

1. Brood pouch is absent in male but it is present in female.
2. Anal styles are present in male but they are absent in female.
3. Male cockroach has narrow and long abdomen but Female has short and broad abdomen.

Question 51.
What is the function of mushroom gland in cockroach?
Answer:
Mushroom gland

1. functions as an accessory reproductive gland
2. helps in the forming the inner layer of the spermatophore which nourishes the sperms.

Question 52.
Compare the utriculi majores and utriculi breviores of the mushroom gland functionally.
Answer:

1. Utriculi majores are long slender peripheral tubules which form inner layer of spermato-phore.
2. Utriculi breviores are short central tubules which nourish the sperms.

Question 53.
How many ovarioles are present in a single ovary of periplaneta and what are the two parts of a single ovariole?
Answer:

1. ‘8’ ovarioles are present in a single ovary of periplaneta.
2. Two parts of a ovary are (i) Germarium, a tapering anterior filament (ii) Vitellarium a posterior wider parts of ovariole.

Question 54.
What are phallomeres?
Answer:

1. Phallomeres are the male external genital organs which surround the male genital opening.
2. The phallomeres help in copulation.
3. These are three types; right, left and ventral phallomeres.

Question 55.
What are gonapophyses?
Answer:

1. Gonapophyses are copulatory structures in both male and female cockroaches.
2. In male they are called phallomeres and help in copulation.
3. In female three pairs of chitinous plates are present around female genital opening.
4. They act as ovipositors and guide the ova into oothecal chamber.

Question 56.
How is colleterial gland helpful in reproduction of Periplaneta?
Answer:

1. A pair of branched colleterial glands are present in cockroach opening into female genital pouch separately.
2. Their secretion help in formation of hard egg case called ootheca around the eggs.

Question 57.
What is paurometabolous develbpnient?
Answer:

1. In cockroaches, the metamorphosis is gradual through nymphal stages. The nymph undergoes 13 moults to become adults.
2. This type of metamorphosis with nymph as intermediate state is called paurometabolous metamorphosis.

Short Answer Questions

Question 1.
Draw a neat labelled diagram of the mouthparts of cockroach? [AP, TS M-16,19] [AP-18] [AP MAY-17,19]
Answer:

Question 2.
Describe the physiology of digestion in cockroach?
Answer:
Physiology of Digestion in Cockroach: It is described by three ways.
1) Food collection:

1. Food is collected with the help of olfactory sensillae on antennae, labial and maxillary palps.
2. The food is seized with forelegs, labrum and labium.
3. The food is held by lacinia, galea, glossae and paraglossae during chewing.
4. Labrum and labium prevent the food from falling down.
5. The food is mixed with saliva during mastication with mandibles.

2) Digestion:

1. The masticated food mixed with saliva passes into crop through pharynx and oesophagus.
2. In crop the food is mixed with digestive enzymes regurgitated from mesenteron.
3. Crop has no digestive glands.
4. Most of the food is digested in crop.
5. The partly digested food is passed through bristles of gizzard and stomodeal valve into mesenteron.

3) Enzyme Action:

1. Amylase of salivary juice converts starches into disaccharides.
2. Invertase from mesenteron digests sucrose into glucose and fructose.
3. Maltase converts maltose to glucose.
4. Lipase converts lipids into fatty acids and glycerol.
5. Protease digests proteins into amino acids.
6. Micro organisms of hind gut produce cellulase which converts cellulose into glucose.
7. Digested food is absorbed in mesenteron. Undigested food goes into hind gut where water is reabsorbed. Remaining undigested food is released as dry pellets (faecal matter).

Question 3.
Draw a neat labelled diagram of the salivary apparatus of cockroach. [IPE-13]
Answer:

Question 4.
What is haemocoel ? Describe it with reference to periplaneta.
Answer:
Haemocoel:

1. Haemocoel is the functional body cavity of an anthropod, which is filled with blood.
2. It is formed by blastocoel and true coelom.
3. It is divided into three sinuses by two horizontal muscular membranes called dorsal diaphragm and ventral diaphragm.
4. Both the diaphragms have valvular pores.
5. There is a series of paired traingular muscles, called alary muscles.
6. One pair of muscles are present in each segment, on the lateral sides of the body.
7. The dorsal diaphragm is between pericardial sinus and perivisceral sinus.
8. The ventral diaphragm is between perivisceral sinus and perineural sinus.
9. Pericardial sinus surrounds thirteen chambered heart.
10. Perivisceral sinus surrounds visceral organs. 11) Perineural sinus surrounds ventral nerve cord.
11. Perivisceral sinus is large and other two are small.

Question 5.
Describe the structure and function of the heart in Periplaneta?
Answer:
Structure and Function of Heart of Cockroach:

1. The heart of cockroach is located dorsally in pericardial sinus below the terga of thorax and abdomen.
2. It is a long muscular contractile tube with 13 chambers.
3. Three chambers are in thorax and ten in abdomen.
4. Valves are present in between chambers directing blood anteriorly.
5. The posterior end of heart is closed.
6. The first chamber is continued as aorta.
7. Except the last chamber, every chamber has one opening on each side called ostia.
8. The ostia have valves which allow blood only into heart chambers.

Question 6.
Describe the process of blood circulation in Periplaneta?
Answer:
Blood circulation in Cockroach:

1. The circulatory system in cockroach is open type.
2. There are no blood vessels.
3. Blood channels or sinuses are present.
   
4. Blood fills the coelom. The coelom is haemocoel and blood is haemolymph.
5. There is a 13 chambered heart dorsally with lateral ostia and valves,
6. Heart is contractile and muscular.
7. When the heart contracts the blood flows forward through the aorta into head sinus.
8. From head sinus blood flows into perivisceral sinus and perineural sinus.
9. The alary muscles contract and pulls the pericardia septum downwards.
10. The volume of pericardial sinus increases.
11. Blood flows into pericardial sinus through the apertures of pericardial septum.
12. The alary muscles relax. Volume of pericardial sinus decreases.
13. Blood flows into heart. Hearts contracts and circulation continues.
    

Question 7.
How do contraction and relaxation of alary muscles help in circulation?
Answer:
Alary muscles and circulation of blood:Alary muscles are triangular paired muscles.

1. The broad sides of the muscle are attached pericardial septum.
2. The narrow parts are attached tergal plates. Every segment has one pair of these muscles.
3. Contraction of alary muscles pulls the pericardial septum downwards.
4. It increases the volume of pericardial sinus.
5. Blood flows into pericardial sinus from perivisceral sinus through the pores of pericardial septum.
6. Relaxation of alary muscle bring the pericardial septum to its normal position.
7. The blood flows into heart when the heart contracts blood flows through aorta, head sinus into perivisceral and perineural sinuses.

Question 8.
Describe the structure of trachea of cockroach?
Answer:
Tracheae:

1. All the stigmata open internally into small chambers called atria.
2. In thoracic region, horizontal tracheae arise from atria.
   They join to form dorso cephalic and ventrocephalic trunks.
3. Branches from these trunks enter various parts of head.
   Lateral longitudinal trunks are also present.
4. Three tracheal tubes arise from each abdominal atrium.
5. They open into 3 longitudinal trunks, namely dorsal, lateral and ventral longitudinal trunks.
6. These trunks of both side are connected by commissural tracheae.
7. Branches are given out from all these trunks to various parts of the body.
8. The tracheal wall has three layers. They are
   (i) Outer basement membrane (ii) Middle epithelium (iii) Inner cuticle called intima.
9. Intima is produced into a spiral thickening called Taenidia.
10. Taenidia prevent the collapse of tracheae, when air is not present in it.

Tracheoles:

1. Trachea ends in tracheoblast cell. It has several intra cellular tubules called tracheoles.
2. Intima and ctenidia are absent in tracheoles. Their inner surface is lined by a protein called trachein.
3. Tracheoles are filled with tracheolar fluid.
   

Question 9.
Explain the structure of malpighian tubules?
Answer:
Malpighian tubules: They are long yellow unbranched tubules attached to extreme anterior end of ileum, opening into it. They do not open into coelom but freely move in it. There are 6 to 8 bundles of tubules, each bundle containing 15 to 25 tubules.

1. Each tubule is lined inside by glandular epithelium with brush border.
2. The distal portion (closed end) is secretory and proximal part is absorptive.
3. The glandular cells collect water, salts and CO₂ and nitrogenous wastes from haemolymph and secrete into lumen of tubule.
4. The proximal part reabsorbs water and certain salts from lumen of the tubule.
5. By contraction of the tubule, urine passes into ileum, where more water is absorbed and solid uric acid is excreted.
6. Removing excretory wastes through alimentary canal is an adaptation for conservation of water.
   

Question 10.
What are different excretory organs in Periplaneta? Describe the process of excretion in detail.
Answer:
Excretory organs in Periplaneta(Cockroach):
The cockroach is uricotelic. The excretory matter is uric acid. The excretory organs are

1. Malpighian tubules
2. Fat bodies
3. Uricose glands
4. Nephrocytes
5. Cuticle

1) Malpighian tubules: They are long yellow unbranched tubules attached to extreme anterior end of ileum, opening into it. They do not open into coelom but freely move in it. There are 6 to 8 bundles of tubules, each bundle containing 15 to 25 tubules.

• Each tubule is lined inside by glandular epithelium with brush border.
• The distal portion (closed end) is secretory and proximal part is absorptive.
• The glandular cells collect water, salts and CO₂ and nitrogenous wastes from haemolymph and secrete into lumen of tubule.
• The proximal part reabsorbs water and certain salts from lumen of the tubule.
• By contraction of the tubule, urine passes into ileum, where more water is absorbed and solid uric acid is excreted.
• Removing excretory wastes through alimentary canal is an adaptation for conservation of water

2) Fat bodies: Carpora adiposa are lobed white bodies with urate cells, These cells absorb and store uric acid for life. It is called storage excretion.

3) Uricose glands: They are utriculi majoris of mushroom gland. Uric acid is stored in these glands and discharged during copulation.

4) Cuticle: Nitrogenous wastes are deposited in cuticle and eliminated during ecdysis.

Question 11.
How does Periplaneta conserve water? Explain it with the help of excretion in it?
Answer:
1) Conservation of water In Cockroach: Conservation of water is essential for terrestrial forms like cockroach. The parts of the body which prevents escape of water are cuticle, rectal papillae and malpighian tubules. The cuticle is hard and waxy. It prevents loss of water by evaporation. Rectal papillae are present in rectum as six longitudinal folds. They absorb water from undigested food.

2) Malpighian tubules: These tubules are like test tubes and open in anterior part of ileum. The closed end freely float in haemocoel. The proximal part that is connected to ileum absorb water and salts from urine. The remaining solid uric acid is released into ileum.

Question 12.
Describe the structure of an ommatidium and label its parts.
Answer:
Structure of ommatidiuni: A typical ommatidium is an elongation sub unit of the compound eye. It is composed of about 2000 functional units called ommatidia. Ommatidia are optically independent.

It consists of the following parts.
1) Cornea: It is the outer most part and corresponds to a ‘hexagonal facet’ of the compound eye.

• It is a biconvex transparent structure. It allows light.
• It is secreted by specialized epidermal cell (comeagen cells).
• Cornea is the ‘refractive region of ommatidium’

2. Corneagen (or) lenticular cells: These are two transparent cells formed from the special¬ized cells ‘Epidermal cells and secrete cornea’.

3. Vitrellae or Cone cells (Semper cells): These are four transparent more (or) less conical cells present below the comeagen cells.

• Vitrellae are surrounded by transparent crystalline cone which is secreted by the cone cells.

4. Crystalline cone: It is the transparent conical and Secreted by the vitrellae and is surrounded by them.

• Both cornea and crystalline cone made the dioptrical or focussing region of the ommatidium.
• Crystalline cone focuses the light on to the next part of the ommatidium.

5. Retinulae: It is the innermost part and contains seven elongated cells.

• Each cell contains microvilli which collectively form a ‘rhabdomere’ which contains photoreceptor pigments.
• In the centre of the ommatidium, rahabdomeres fuse along the axis to form rhabdome.
• Retinulae are the nerve cells from which sensory nerve fibers leave as the optic nerve to the ‘Protocerebrum’, which are the photoreceptors.
• ‘Retinal’ or ‘receptor region’ is formed by the Rhabdome and retinulae which is surrounded by seven secondary pigment cells.
• These cells absorb light and serve to isolate each ommatidium from the retinal pigment sheath.

6. Function: In diurnal and nocturnal insects, the position of retinulae is different. So ommatidia makes two types of images, which are ‘Apposition and superposition images’.

Question 13.
Draw a neat labelled diagram of ommatidium. [TS M-15,20] [TS May-17] [AP M-15]
Answer:

Question 14.
How can you identify the male and female cockroaches, explain it describing the chief features of the external and internal genetalia.
Answer:
1) Sexual dimorphism is present in cockroach.

• Brood pouch is absent in male. Brood pouch is present in female.
• Anal styles are present in male and absent in female.
• Male has narrow and long abdomen. Female has short and broad abdomen.

2) Male genetalia: Gonopore (male genital pore) is present on the ventral phallomere. Surrounding the male genital pore there are three asymmetrical structures called phallomeres or ganapophyses.They help in copulation. The left phallomere bears a pesudopenis and titillator.

3) Female genetalia: In female, there is a genital pouch. It is formed by 7th, 8th and 9th abdominal sternal plates. The sternum of 7th segment is boat shaped and forms the floor and side walls of the pouch.

• The 8th sternum forms the anterior wall of the pouch. The 9th sternum forms the roof of the pouch. The outer part of chamber is gynatrium and posterior part is vestibulum.
• Three pairs of small chitinous plates (gonapophyses ) are present around female gonopore.
• They act as ovipositors and guide ova into oothecal chamber. They also help in copulation.

Question 15.
Describe the male reproductive system of cockroach.
Answer:
1. Male reproductive system: It Consists of a pair of testes, a pair of vasa deferentia, ejaculatory duct, mushroom shaped gland, seminal vesicles, phallic gland, gonopore surrounded by gonapophyses.

• Testes are a pair of elongated lobed bodies present on lateral sides of 4th, 5th and 6th abdominal segments.
• Vas deferens is a narrow tube arising from testis. The two vasa deferentia run backwards and open in a wide tube, the ductus ejaculatorius in 7th segment.
• Mushroom shaped gland is present 6th and 7th segments. It has two types of tubules.
  (a) Utriculimajoris- long slender tubules on the periphery. Their secretion forms inner layer of spermatophore.
  (b) Utriculi brevoris- short tubules at the centre their secretion nourishes the sperms.
• These tubules open into anterior part of ejaculatory duct.

2. Seminal vesicles are a pair of sacs present on the ventral side of ejaculatory duct. These sacs store the sperm as spermatophores.

• Gonopore is the male genital pore present on the ventral phallomere.
• Phallic gland whose function is not known also opens near gonopore.
• Phallomores (gonapophyses) are 3 chitinous asymmetrical structure present around gonopore. They help in copulation,

Question 16.
Describe the female reproductive system of cockroach?
Answer:
1. Female reproductive Systemtlt consists of a pair of ovaries, oviducts, vagina, spermathecae, colleterial glands and genital pouch.

2. Ovaries: A pair of large ovaries are present laterally in 2,3,4,5,6 segments surrounded by fat bodies. Each ovary has eight ovarioles. Each ovariole has tapering part, the germarium and wider part, the vitellarium.

• Germarium has ova at different stages of development.
• Vitellarium has mature ova with yolk.

3. Oviducts: The ovarioles unite to form a short wide oviduct vagina. The oviducts open into a short median vagina.

• Female genital pore is a vertical slit in vagina.
• Spermathecae consists of a left sac and right filament in 6th segment which opens on a spermathecal papilla in dorsal part of genital pouch.
  

4. Colleterial glands: A pair of colleterial glands are present behind ovaries opening into genital pouch. Their secretion forms egg case or ootheca around eggs.

• Genital pouch is formed 7th, 8th and 9th sternum.
• 7th sternum forms the floor of the pouch.
• 8th sternum forms the anterior wall of the pouch.
• 9th sternum forms the anterior roof of the pouch.
• Anterior part of genital pouch is the gynatrium and posterior part is oothecal chamber.
• Gonapophyses are three pairs of plate like chitinous structures around female genital pore.
• Gonapophyses act as ovipositors and help in copulation.

Long Answer Questions

Question 1.
Describe the structure of the head of a cockroach, with the help of a neat labelled diagram?
Answer:
Structure of the head of Cockroach:

1. Head: The head of cockroach is triangular in shape.
2. The head hangs at right angles to the body with the mouthparts directed downwards. Hence the head is called as hypognathous.
3. The head of cockroach is formed by the fusion of’six embryonic segments’.
4. It is movable and is attached to the thorax by a short neck called cervicum.
5. The head is covered by six chitinous sclerites to form a head capsule.
6. The top of the head between the eyes is called vertex.
7. The vertex has two sclerites called ‘epicranial plates’ connected by an ‘epicranial suture’.
8. Below the vertex, the sclerites covering the head in front are a large frons, a narrow rectangu lar clypeus and a movable labrum.
9. Below the compound eyes there are ‘cheek sclerites’ or ‘genae’ which cover the sides of the head.
10. At the back of the head capsule, there is a large opening called occipital foramen.
11. It is bordered by a sclerite called occiput.
12. The occipital foramen forms a passage for the oesophagus, aorta, nerve cord and tracheae.
13. A small whitish speck called fenestra or ‘ocellar spot’ or ’simple eye1 is present at the base of each antenna.
14. In the first and third segments of the head Appendages are absent
15. The second segment contains a pair of long, slender and segmented antennae, one on each side of the head.
16. The fourth segment contains a pair of mandibles.
17. The fifth segment contains a pair of ’first maxillae’.
18. The sixth segment contains a pair of’second maxillae’, which fuse to form the labium
19. The appendages of fourth, fifth and sixth segments of head along with labrum and hypophar ynx constitute the bitting and chewing type of mouth parts of cockroach.
    

Question 2.
Describe the abdomen of cockroach?
Answer:
Abdomen of cockroach:

1. The abdomen of cockroach consists of ten segments.
2. Each abdominal segment is covered by the dorsal tergum, the ventral sternum and the two lateral pleura
3. There are ten terga with only nine sterna, as the tenth sternum is absent.
4. The eighth tergum in the male and both eighth and ninth terga in the female are not visible as they are overlapped by the seventh tergum.
5. The tenth tergum extends beyond the posterior end of the body and has a deep notch / groove in the middle of its free end.
6.  In the male, nine sterna are visible whereas in the female, only seven sterna are visible.
7. In the female, the seventh, eighth and ninth sterna together form a brood pouch.
8. The brood pouch has two parts the anterior genital chamber or gynatrium and posterior oothecal chamber.
9. The posterior end of the abdomen has a pair of anal cerci, a pair of anal styles and gonapophyses in males.
10. Anal cerci are jointed and arise from the lateral sides of the tenth tergum and are found in both the sexes.
11.  The anal styles which are seen only in males are without joints and arise from the ninth sternum.
12. The gonapophyses are small chitinous processes arising from the ninth sternum in the males and eighth and ninth sterna in the females. They are the external genital organs.
13. The anus is at the posterior end of the abdomen in the 10th segment.
14. The genital aperture in male is present just below the anus on one of the gonapophyses and in female it is located at middle of the eighth sternum.

Question 3.
Describe the digestive system of cockroach with the help of a neat labelled diagram. [AP -16,17,20] [TS-17,18,19]
Answer:

Digestive system of Cockroach:
The digestive system of cockroach consists of I. Alimentary canal II. Digestive glands.

I. Alimentary canal: The alimentary canal extends from mouth to anus.
It is divided into 3 regions. They are

1. Foregut
2. Midgut
3. Hindgut

(1) Foregut (Stomodaeum):

1. Foregut has pharynx, oesophagus, crop and gizzard.
2. Pharynx is a very short tube. It leads into a narrow tubular oesophagus.
3. Oesophagus opens into a sac like crop. It stores food for digestion.
4. Its outer surface is covered by tracheal tubes.
5. Behind the crop there is a thick walled muscular gizzard.
6. The chitinous inner lining of the gizzard has six powerful teeth, vii ) These teeth form an efficient grinding apparatus.
7. Thus Gizzard acts as a grinding mill and sieve.
8. The membranous funnel projected into mesenteron from gizzard is called stomdeal valve.
9. This valve prevents backward movement of food from mesenteron into gizzard.

(b) Midgut(Mesenteron):

1. It is a short narrow tube.
2. Anterior part of midgut contains 6 to 8 finger shaped diverticula called hepatic caecae.
3. These are helpful in digestion and absorption of digested food material.
4. The anterior part of midgut is secretory and posterior part is absorptive.
5. Secretory part secretes enzymes.
6. The food bolus is surrounded by chitinous and porous peritrophic membrane which is secreted by the funnel-like stomodeal valve of the gizzard.
7. lt protects midgut wall from hard food particles.

(c) Hindgut (Proctodaeum):

1. It is a long coiled tube.
2. The hindgut is divided into ileum, colon and rectum.
3. There is a sphincter between mesenteron and hindgut.
4. The sphincter prevents back movement of undigested food and uric acid from the hindgut to midgut.
5. Ileum collects uric acid from Malpighian tubules which are present at the anterior end of ileum
6. Colon is a long, coiled tube. It opens into short and wide rectum which opensout through anus.
7. Rectum has 6 longitudinal folds called rectal papillae. They absorb water from undigested food.
8. Entire hindgut is internally lined by cuticle.

II) Digestive glands: The digestive glands of cockroach includes

1. Salivary glands
2. Hepatic caecae
3. Glandular cells of mesenteron.

1) Salivary glands:

1. A pair of salivary glands are present on either sides of the crop.
2. Each salivary gland has two lobes
3. Each lobe has many lobules called acini.
4. Each acinus is made up of secretory cells called zymogen cells.
5. All the zymogen cells are connected by ductules.
6. The ductules open into a common salivary duct. The two common salivary ducts are joined to form the median salivary duct.
7. There is a pair of salivary receptacles to store saliva.
8. The receptacular ducts unite to form common receptacular duct.
9. The median salivary duct is connected to common receptacular duct to form an efferent salivary duct.
10. The efferent salivary duct opens at the base of hypopharynx in mouth cavity.
11. Saliva is secreted by zymogen cells which contains starch digesting enzyme amylase.

2) Hepatic caecae: There are six to eight finger like diverticula called hepatic caecae which contain secretory and absorptive cells

3) Glandular cells of Mesenteron: Glandular cells of mesenteron secrete maltase, invertase, proteases and lipase.

Question 4.
Describe the blood circulatory system of Periplaneta in detail and draw a neat and labelled diagram of it.
Answer:

Blood Circulatory System of Periplaneta:

• The Circulatory system transports digested food, hormones from one part of the body to other parts of the body.
• The blood flows freely in spaces of haemocoel. Hence this circulatory system is open type. The three main parts of circulatory system are (a) Haemocoel (b) Heart (c) Blood.

(a) Haemocoel:

• It is divided into three sinuses by two horizontal muscular membranes called dorsal diaphragm and ventral diaphragm.
• Both the diaphragms have valvular pores.
• There is a series of paired traingular muscles, called alary muscles.
• One pair of muscles are present in each segment, on the lateral sides of the body.
• The dorsal diaphragm is between pericardial sinus and perivisceral sinus.
• The ventral diaphragm is between perivisceral sinus and perineural sinus.
• Pericardial sinus surrounds heart.
• Perivisceral sinus surrounds visceral organs.
• Perineural sinus surrounds ventral nerve cord.
• Perivisceral sinus is large and other two are small.

(b) Heart:

• The heart is dorsal. It is present below the tergal plates surrounded by pericardial sinus.
• It is long, muscular, contractile, 13 chambered tube.
• Every chamber opens into its anterior chamber by a valvular opening.
• The posterior end of heart is closed and opens anteriorly into aorta.
• At the posterior side of each chamber, except the last, there is a pair of small apertures called ‘ostia’, one on each side.
• Ostia have valves which allow the blood to pass only into the heart from the dorsal sinus.

(c) Blood (haemolymph):

• The blood of Periplaneta is colourless and called haemolymph.
• It consists of plasma and phagocytic haemocytes.
• There is no respiratory pigment in the blood and so it plays no major role in respiration.

Important functions of Blood:

• Blood absorbs and distributes digested food.
• It transports nitrogenous wastes from various parts of the body to excretory organs.
• It carries phagocytes to the places of infection.
• It transports hormones to target organs.

Circulation of Blood:

• Blood flows from heart to aorta and to head sinus by the contraction of heart muscles.
  From head sinus, blood flows into perivisceral and perineural sinuses.
• Alary muscles contract pulling down the pericardial septum. Blood flows into pericardial sinus from the perivisceral sinus.
• Alary muscles relax and pericardial septum moves up forcing blood into heart and circulation continues.

Question 5.
The blood circulatory system of Periplaneta is of open type. Illustrate the statement describing the course of circulation in it. [AP M-19]
Answer:

Blood circulatory system of Periplaneta:

1. The blood circulatory system helps in the transportation of digested food, hormones etc.
2. Periplaneta has an open type of circu¬latory system as blood flows freely with in the body cavity.
3.  Blood flows from heart to aorta and from there it enters into head sinus by the contraction of heart muscles.
4. From head sinus, blood flows into perivisceral and sternal sinuses.
5. Blood flows into pericardial sinus when alary muscles contract pulling down the pericardial septum.
6. The alary muscles when relaxed, the pericardial septum moves to its original position.
7. This causes forcing the blood to enter chambers of the heart through ostia.
8. The flow of blood is always from heart to aorta from there to head sinuses; from there to perivisceral and perineural sinuses; from there to pericardial sinus and again to heart.
   

Hence the statement that ‘the blood circulatory system of peiplaneta is open is justified.

Question 6.
Describe the respiratory system of cockroach with the help of neat and labelled diagrams? [AP-18,19]
Answer:

1. Respiratory system of cockroach:

• The respiratory system of cockroach is called trancheal system.
• It consists of (a) Stigmata (b) Tracheae (c) Tracheoles.

(a) Stigmata (spiracles):

• The external openings of tracheal system are called stigmata (or) spiracles.
• There are ten pairs of spiracles.
• The first two pairs are in thorax. Remaining 8 eight pairs are present in the abdominal segments.
• Spiracles are located on the pleura.
• The respiratory system of cockroach is described as polypneustic (having more than 3 pairs of spiracles) and Holopneustic (all the spiracles are functional).
• All spiracles are valvular. Each spiracle is supported by a chitinous ring peritreme.
• The spiracle has hair like trichomes to filter dust from air.

(b) Tracheae:

• All the stigmata open internally into small chambers called atria.
• In thoracic region, horizontal tracheae arise from atria.
• They join to form dorso cephalic and ventrocephalic trunks.
• Branches from these trunks enter various parts of head.
  Lateral longitudinal.trunks are also present.
• Three tracheal tubes arise from each abdominal atrium.
• They open into 3 longitudinal trunks, namely dorsal, lateral and ventral longitudinal trunks.
• Branches are given out from all these trunks to various parts of the body.
• The tracheal wall has three layers. They are
  (i) Outer basement membrane (ii) Middle epithelium (iii) Inner cuticle called intima.
• Intima is produced into a spiral thickening called Taenidia.
• Taenidia prevents the collapse of tracheae, when air is not present in it.

(c) Tracheoies:

• Trachea ends in tracheoblast cell. It has several intra cellular tubules called tracheoies.
• Intima and tenidia are absent in tracheoies. Their inner surface is lined by a protein called trachein.
• Tracheoies are filled with tracheolar fluid.

2. Mechanism Respiration involves two events namely inspiration and expiration.

• The muscles that help in this process are dorsoventral (principal muscles) and ventral longitudinal muscles.

3. Inspiration: Taking in of air is inspiration. The volume of body is increased by relaxation of dorsoventral and ventral longitudinal muscles. Air is drawn into tracheal tubes and reaches tissues.

• During inspiration, thoracic spiracles are kept open and abdominal spiracles are closed.
• Inspiration is a passive process (does not use energy)

4. Expiration: Sending out air is Expiration.

• During expiration, thoracic spiracles are closed. The thoracic spiracles are closed and abdominal spiracles are kept open.
• Expiration is an active process as it uses energy.
• Opening and closing of spiracles is influenced by CO₂ tension in haemolymph and O₂ tension in trachea.
  

Question 7.
Describe the nervous system of periplaneta and draw a labeled diagram of it.
Answer:
Nervous system of Periplaneta:
Nervous system of cockroach consists of three parts.
I. Central nervous system. II. Peripheral nervous system. III. Autonomous nervous system.

I. Central nervous system: It consists of a nervering and a ganglionated double ventral nerve cord.

1. ‘Nerve ring’ is present around the oesophagus.
2. It is formed by the brain, sub-oesophageal ganglion, circum- oesophageal connectives and ventral nerve cord.

a) Brain:

1. It is mainly a sensory and an endocrine centre present above the oesophagus.
2. It contains three lobes: Protocerebrum, Deutocerebrum & Tritocerebrum.
3. The protocerebrum receives impulses from the compound eyes through optic nerves.
4. The deutocerebrum receives impulses from antennae through antennal nerves.
5. The tritocerebrum receives impulses from the labrum.
6. So, brain is principally ‘sensory’ in function.

b) Sub-oesophageal ganglion: It is below the oesophagus.lt is the motor center that controls the movements of mouthparts, legs and wings. It is formed by the fusion of paired ganglia of mandbular, maxillary and labial segments of the head.

c) Circum-oesophageal connectives: A pair of circum-oesophageal connectives is present around the oesophagus, connecting the tritocerebral ganglion with sub oesophageal ganglia.

d) Ventral nerve cord: The two ventral nerve cords are solid and ganglionated. They arise from the suboesophageal ganglion and extend upto the 7th abdominal segment. The two nerve cords remain separate except at the ganglia.

II. Peripheral Nervous System:

1. It consists of nerves arising from the central nervous system.
2. It receives a pair of, optic nerves, from the compound eyes, a pair of antennal nerves, from the antennae and a pair of labral nerves, from the labrum.
3. Motar neurons of the frontal nerve to the frontal ganglion join the sensory neurons of the labral nerve to form the labrofrontal nerve arising from the tritocerebrum.
4. Sub – oesophageal ganglion gives off motor nerves to the mandibles, maxillae, labium, wings and legs. It is the principal ‘motor centre’ in the body.
5. Thoracic ganglia supply nerves to the parts of their respective segments.
6. Metathoracic ganglia send nerves to the first abdominal segment also.
7. Nerves from the first four abdominal ganglia supply to the organs of the segments2 – 6 serially (the 1st to the 4lh ganglia innervate segments 2nd to 5th respectively).
8. The 5th ganglion present in the 6th segment innervates the organs of the 6th segment.
   All the organs present in 7th to 10th segments receive nerves from the last abdominal ganglion (present in the 7th segment).
9. The organs include the reproductive organs, copulatory appendages besides anal cerci.

III. Autonomous Nervous system:

1. This system is also called stomatogastric nervous system or ‘visceral nervous system’.
2. It controls the visceral organs, particularly the muscles of the alimentary canal, and the heart.
3. Autonomous nervous system includes four ganglia, a frontal ganglion on the dorsal wall of the pharynx, in front of the brain, hypocerebral ganglion or occipital ganglion above the oesophagus, behind the brain, a visceral ganglion or ingluvial ganglion on the wall of the crop and a proventricular ganglion on the gizzard.
4. These ganglia contain the ‘somata’ of the post ganglionic motor neurons.
5. Preganglionic motor neurons of tritocerebrum go to the frontal ganglion as labrofrontal and frontal nerve.
6. Frontal ganglion is connected to the hypocerebral ganglion by a ‘recurrent nerve’.
7. Hypocerebral ganglion is connected to the visceral ganglion and in turn the visceral ganglion is connected to proventricular ganglion.
   

Question 8.
Describe the reproductive system of Periplaneta and draw neat and labelled diagrams of it.
Answer:
Reproductive system of Cockroach: Cockroach is unisexual. Sexual dimorphism is present.
Males have a pair of anal styles which are absent in female. Male has narrow abdomen and females have broad abdomen. Brood pouch is present in female and absent in male.

I. Male reproductive system: It consists of a pair of testes, a pair of vasa deferentia, ejaculatory duct, mushroom shaped gland, seminal vesicles, phallic gland, gonopore surrounded by gonapophyses.

• Testes are a pair of elongated lobed bodies present on lateral sides of 4th, 5th and 6th abdominal segments.
• Vas deferens is a narrow7 tube arising from testis. The two vasa deferentia run backwards and open in a wide tube, the ductus ejaculatorius in 7th segment.
• Mushroom shaped gland is present 6th and 7th segments. It has two types of tubules.
  (a) Utriculimajoris- long slender tubules on the periphery. Their secretion forms inner layer of spermatophore.
  (b) Utriculi brevoris- short tubules at the centre their secretion nourishes the sperms.
• These tubules open into anterior part of ejaculatory duct.

Seminal vesicles are a pair of sacs present on the ventral side of the ejaculatory duct. These sacs store the sperms as spermatophores.

Gonopore is the male genital pore present on the ventral phailomere.

Phallic gland whose function is not known also opens near gonopore.

Phallomores (gonapophyses) are 3 chitinous asymmetrical structure present around gonopore. They help in copulation.

Female reproductive System:It consists of a pair of ovaries, oviducts, vagina, spermathecae, colleterial glands and genital pouch.

Ovaries: Apair of large ovaries are present laterally in 2,3,4,5,6 abdominal segments surrounded by fat bodies. Each ovary has eight ovarioles. Each ovariole has tapering part, the germarium and wider part, the vitellarium.

Germarium has ova at different stages of development. Vitellarium has mature ova with yolk. Vitellarium has mature ova with yolk.

Oviducts: The ovarioles unite to form a short wide oviduct vagina. The oviducts open into a short median vagina.

Female genital pore is a vertical slit in vagina.

Spermathecae consists of a left sac and right filament in 6th segment which opens on a spermathecal papilla in dorsal part of genital pouch.

Colleteriai glands: A pair of colleterial glands are present behind ovaries opening into genital pouch. Their secretion forms egg case or ootheca around eggs.

• Genital pouch is formed 7th, 8th and 9th sternal plates.
• 7th sternum forms the floor of the pouch.
• 8th sternum forms the anterior wall of the pouch.
• 9th sternum forms the anterior roof of the pouch.
• Anterior part of genital pouch is the gynatrium and posterior part is oothecal chamber.
• Gonapophyses are three pairs of plate like chitinous structures around female genital pore.
• Gonapophyses act as ovipositors and help in copulation.
• Cockroach is paurometabolous as the development is gradual through nymphal stages.
• Shedding of exoskeletron is called moulting or ecdysis. After the last ecdysis the nymph grows into fully formed adult.

 

Multiple Choice Questions

Question 1.
Antennae of cockroach have
1. gustatory receptors
2. auditory receptors
3. tactile receptors
4. tactile and olfactory receptors
Answer:
4. tactile and olfactory receptors

Question 2.
Blood of cockroach is colourless because of
1. the presence of respiratory pigments without metal ions
2. the absence of respiratory pigments
3. the presence of colourless oxygen carrying cells
4. the presence of haemocyanin
Answer:
2. the absence of respiratory pigments

Question 3.
Cockroach exhibits
1. tripod movement
2. cursorial nature
3. rare flight
4. all the above
Answer:
4. all the above

Question 4.
Development in cockroach is
1. holometabolous
2. paurometabolous
3. ametabolous
4. hemimetabolous
Answer:
2. paurometabolous

Question 5.
Excretory organ in cockroach is
1. Malpighian
2. Malpighian tubules
3. hepatic caecae
4. metanephridia
Answer:
2. Malpighian tubules

Question 6.
Fat bodies of cockroach are analogous to vertebrate
1. spleen
2. liver
3. kidney
4. adipose tissue
Answer:
2. liver

Question 7.
Gizzard ¡n cockroach acts as
1. Grinding mili and sieve
2. Sieve and storage organ
3. Only grinding miii
4. Only storage organ not sieve or ginding mill
Answer:
1. Grinding mili and sieve

Question 8.
Heart of cockroach is
1. 13 chambered
2. 29 chambered
3. 9 chambered
4. 6 chambered
Answer:
1. 13 chambered

Question 9.
In cockroach, wings are absent from
1. prothorax
2. mesothorax
3. metathorax
4. orthodox
Answer:
1. prothorax

Question 10.
The orientation of head In cockroach ¡s
1. Hypognathous
2. Epignathus
3. Basitropic
4. Diapsid
Answer:
1. Hypognathous

Question 11.
The leg of cockroach is attached to the thorax by
1. Trochanter
2. Coxa
3. Tibia
4. Tarsus
Answer:
2. Coxa

Question 12.
The tongue of cockroach ¡s represented ¡n the form of
1. Epipharynx
2. Hypopharynx
3. Pronotum
4. Hypoglossus
Answer:
2. Hypopharynx

Question 13.
The top of the head of cockroach located between the two compound eyes is termed
1. Vertex
2. Frons
3. Occiput
4. Genae
Answer:
1. Vertex

Question 14.
The hardest part of the cuticle of cockroach Is
1. endocuticle
2. epicuticle
3. exocuticle
4. epidermis
Answer:
3. exocuticle

Question 15.
Cockroach feeds on
1. all solid and liquid diets
2. all solid plant materials only
3. all solid animal materials only
4. all kinds of solid materials
Answer:
4. all kinds of solid materials

Question 16.
The number of salivary glands in cockroach are
1. 3 pairs
2. 2 pairs
3. 5 pairs
4. 1 pair
Answer:
4. 1 pair

Question 17.
In cockroach, the nature of ventriculus is functionally
1. secretory and excretory
2. secretory and absorptive
3. absorptive and excretory
4. only excretory
Answer:
2. secretory and absorptive

Question 18.
In cockroach, most of the food is digested in the
1. Mesenteron
2. Gizzard
3. Crop
4. Ileum
Answer:
3. Crop

Question 19.
The digestive system of earthworm and cockroach share a common feature of
1. Non muscular gut
2. Presence of intestinal caeca
3. Straight gut
4. Excretory organs opening in to the gut
Answer:
4. Excretory organs opening in to the gut

Question 20.
The total number of heart chambers in cockroach is
1. 10 atria, 3 ventricles
2. 6 atria, 7 ventricles
3. 7 atria, 6 ventricles
4. 13 chambers
Answer:
4. 13 chambers

Question 21.
Respiratory pigment is absent in the blood of
1. Man
2. Earthworm
3. Crab
4. Cockroach
Answer:
4. Cockroach

Question 22.
The principal muscles of respiration in cockroach are
1. Ventral muscles
2. Dorsoventral muscles
3. Ventral longitudinal muscles
4. Only dorsal muscles
Answer:
2. Dorsoventral muscles

Question 23.
In cockroach, each spiracle leads into a small chamber called
1. Tracheoblast
2. Atrium
3. Commissural trachea
4. Peritreme
Answer:
2. Atrium

Question 24.
Respiratory system of cockroach is formed by
1. Book lungs
2. Book gills
3. Trachea
4. Ctenidia
Answer:
3. Trachea

Question 25.
In cockroach, the passive activity is
1. expiration
2. inspiration
3. tripod movement
4. flight
Answer:
2. inspiration

Question 26.
Gustatory sensilla in cockroach arc sensitive to
1. Touch
2. Chemicals
3. Taste
4. Sound
Answer:
3. Taste

Question 27.
In cockroach, the protocerebrum receives sensory impulses from
1. Antenna
2. Labium
3. Compound eyes
4. Mandibles
Answer:
3. Compound eyes

Question 28.
Mouthparts of cockroach are under the control of
1. Brain
2. Suboesophageal ganglia
3. Cricumoesophageal connectives
4. Subpharyngeal ganglia
Answer:
2. Suboesophageal ganglia

Question 29.
The testes in male cockroach are located in
1. 2,3,4 segments
2. 4,5,6 segments
3. 6,7,8 segments
4. in the genital atrium
Answer:
2. 4,5,6 segments

Question 30.
The female cockroach is different from the male
1. In having wings and antennae
2. In having anal styles and anal cerci
3. By the absence of brood pouch and gonapophyses
4. In having a short and broad abdomen and by the absence of anal styles
Answer:
4. In having a short and broad abdomen and by the absence of anal styles

Question 31.
Scientist who coined the name Periplaneta was
1. Linnaeus
2. K.N.Bahl
3. Bermeister
4. D.Gir
Answer:
3. Bermeister

Question 32.
The cockroach of genus Blatta is also called
1. German cockroach
2. Australian cockroach
3. Oriental cockroach
4. American cockroach
Answer:
3. Oriental cockroach

Question 33.
Head of cockroach according to its position is known as %
1. Hypopharynx
2. Hypocyrebral
3. Hypognathous
4. Supragnathus
Answer:
3. Hypognathous

Question 34.
In cockroach, fore wings are called
1. tegmina
2. plantulae
3. pulvillus
4. tarsomere
Answer:
1. tegmina

Question 35.
The correct sequence of arrangement of segments in the leg of cockroach is
1. tibia, trochanter, femur, tarsus and coxa
2. trochanter, coxa, tibia, femur and tarsus
3. coxa, femur, trochanter, tibia and tarsus
4. coxa, trochanter, femur, tibia and tarsus
Answer:
4. coxa, trochanter, femur, tibia and tarsus

Question 36.
Male cockroach and female cockroach can be differentiated by
1. ocelli
2. anal cerci
3. anal styles
4. both (2) and (3)
Answer:
3. anal styles

Question 37.
The number of abdominal segments in male and female cockroach is
1. 10,10
2. 9,10
3. 10,11
4. 8,10
Answer:
1. 10,10

Question 38.
In cockroach, arthrodial membrane is devoid of
1. epicutile
2. exocuticle
3. epidermis
4. endocuticle
Answer:
2. exocuticle

Question 39.
In cockroach, locomotion on rough, surface is helped by •
1. plantulae
2. claws and arolium
3. bristles
4. 1,2 and 3
Answer:
2. claws and arolium

Question 40.
Haepatic caecae of cockroach help in
1. storage of food
2. secretion of digestive enzymes
3. removal of wastes
4. absorption of uric acid
Answer:
2. secretion of digestive enzymes

Question 41.
Cells of salivary glands that secrete saliva are
1. peptic cells
2. chief cells
3. acinar cells
4. oenocytes
Answer:
3. acinar cells

Question 42.
In cockroach, oxygen Is transported by
1. trachea
2. plasma
3. haemoglobin
4. histamine
Answer:
1. trachea

Question 43.
Spiracles of cockroach which are kept open during inspiration
1. first and second pairs
2. first and third pairs
3. first ad tenth pairs
4. second and third pairs
Answer:
2. first and third pairs

Question 44.
The blood of cockroach contains no respiratory pigment. It means that
1. respiration is anaerobic
2. oxygen goes directly into it by diffusion
3. cockroach doçs not respire
4. oxygen goes into tissue by intracellular capillary system
Answer:
2. oxygen goes directly into it by diffusion

Question 45.
Cockroaches are
1. ureotelic
2. ureotelic or ammonotelic
3. uricotelic
4. ammonotelic
Answer:
3. uricotelic

Question 46.
The total number of ganglia present on the ventral nerve cord of cockroach is
1. 6
2. 10
3. 9
4. 12
Answer:
3. 9

Question 47.
Frontal ganglion is connected to the hypocerebral ganglion by
1. Optic nerve
2. Antennal nerve
3. Frontal nerve
4. Recurrent nerve
Answer:
4. Recurrent nerve

Question 48.
Photoreceptor cells of the ommatidium
1. Cone cells
2. Vitrellae
3. Semper cells
4. Retinulae
Answer:
4. Retinulae

Question 49.
Sensory units of subcuticular mechano receptors of chordotonal organs are
1. sensilae
2. scolopidia
3. ommatidia
4. ocelli
Answer:
2. scolopidia

Question 50.
The main difference between male and female cockroach is
1. Jointed appendages
2. Paired antennae
3. Anal cerci
4. Conglobate gland
Answer:
4. Conglobate gland

Question 51.
In cockroach, the ootheca ¡s formed by the secretion of
1. phallic gland
2. collaterial glands
3. mushroom gland
4. conglobate gland
Answer:
2. collaterial glands

Question 52.
The eggs of cockroach are arranged in
1. 8 eggs in two rows
2. 16 eggs in two rows
3. 8 eggs in single row
4. 16 eggs in single row
Answer:
2. 16 eggs in two rows

Question 53.
To attract the male for copulation, female cockroach produces
1. Hormones
2. Pheromones
3. Enzymes
4. Vitamins
Answer:
2. Pheromones

Question 54.
On average female cockroach produces
1. 10—11 Oothecae
2. 11—12 Oothecae
3. 9—10 Oothecae
4. 8—9 Oothecae
Answer:
3. 9—10 Oothecae

Question 55.
Moulting or ecdysis ¡s the
1. shedding of anal styles
2. shedding of exoskeleton
3. hatching of the nymph
4. cleavage of the egg
Answer:
2. shedding of exoskeleton