1st PUC Biology Question Bank Chapter 7 Structural Organisation in Animals

   

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Karnataka 1st PUC Biology Question Bank Chapter 7 Structural Organisation in Animals

1st PUC Biology Structural Organisation in Animals NCERT Text Book Questions and Answers

Question 1.
Answer in one word or one line.
(1) Give the common name of Periplaneta americana.
Answer:
Cockroach

(2) How many spermathecae are found in earthworms?
Answer:
On the ventral side, spermathecal openings are present in between the grooves of 5 and 6, 6 and 7, 7 and 8 and 8 and 9 segments.

(3) What is the position of ovaries in cockroach
Answer:
Ovaries are present in cockroaches in the 4th, 5th, and 6th segments.

(4) How many segments are present in the abdomen of the cockroach?
Answer:
These are ten segments in the abdomen.

(5) Where do you find Malpighian tubules?
Answer:
Malpighian tubules are present at the junction of the midgut and hindgut and help in excretion.

Question 2.
Answer the following:

(i) What is the function of nephridia?
Answer:
Nephridia are the minute openings found in all segments except the first two and their function is to discharge nitrogenous waste.

(ii) How many types of nephridia are found in earthworms based on their location?
Answer:
3 types of nephridia

  • Septal nephridia: present on both sides of intersegmental septa of segment 15 to the last that open into the intestine.
  • Integumentary nephridia: attached to the lining of the body wall of segment 3 to the last that open on the body surface.
  • Pharyngeal nephridia: present as three paired tufts in the 4th, 5th, and 6th segments.

KSEEB Solutions

Question 3.
Draw a labelled diagram of the reproductive organs of an earthworm.
Answer:
1st PUC Biology Question Bank Chapter 7 Structural Organisation in Animals 1

Question 4.
Draw a labelled diagram of the alimentary canal of a cockroach.
Answer:
1st PUC Biology Question Bank Chapter 7 Structural Organisation in Animals 2

Question 5.
Distinguish between the following:

  1. Prostomium and peristomium
  2. Septal nephridium and Pharyngeal nephridium

Answer:
1. Difference between Prostomium and Peristomium
Prostomium:
The prostomium is sensory in function.
Peristomium:
TheTirst body segment is called the peristomium (buccal segment) which contains the mouth.

2. Difference between Septal nephridium and Pharyngeal nephridium
Septal nephridium:
Present on both the side of intersegmental septa of segment 15 to the last that open into the intestine
Pharyngeal nephridium:
Present on both the side of intersegmental septa of segment 15 to the last that open into intestine Pharyngeal nephridia. present as three paired in the 4th, 5th, and 6th segments.

Question 6.
What are the cellular components of blood?
Answer:
Blood consists of plasma, red blood cells (RBCs), white blood cells (WBCs), and platelets.

Question 7.
What are the following and where do you find them in an animal body.

  1. Chondrocytes
  2. Axons
  3. Ciliated epithelium

Answer:
1. Chondrocytes: These are the cells found in cartilage connective tissue. The number of chondrocytes found in cartilage determines how bendy the cartilage is chondrocytes produce and maintain the cartilage matrix. It is present in the tip of the nose, pinna of the ear, joints between the vertebral column, etc.

2. Axon: It is the longest process of a neuron, that conducts the impulse away from the cell body. They are present in all nerve fibres.

3. Ciliated epithelium: When cuboidal or columnar epithelial cells bear cilia, they are called the ciliated epithelium.
Ciliated epithelium is found in the living respiratory tract, bronchioles, and fallopian tubes. It contains goblet cells, which secretes mucus.

Question 8.
Describe various types of epithelial tissues with the help of labelled diagrams.
Answer:
Epithelial tissues provide covering to the inner and outer lining of various organs. The cells of epithelial tissues are compactly packed with a little intercellular matrix.
There are two types of epithelial tissues.

(a) Simple epithelium: Composed of a single layer of cells and functions as a lining for body cavities, ducts, and tubes.

(b) Compound epithelium: consists of two or more cell layers and has a protective function as it does in our skin. They cover the dry surface of the skin, the moist surface of the buccal cavity, pharynx, the inner lining of the ducts of salivary glands, and of pancreatic ducts.
1st PUC Biology Question Bank Chapter 7 Structural Organisation in Animals 3
On the basis of structural modification of the cells, the simple epithelium is further divided into three types. These are:

(i) Squamous: Made of a single thin layer of flattened cells with irregular boundaries. They are found in the walls of blood vessels and air sacs of the lungs and are involved in functions like forming a diffusion boundary.

(ii) Cuboidal: Composed of a single layer of cube-like cells. This is commonly found in ducts of glands and tubular parts of nephrons in kidneys and its main functions are secretion and absorption. The epithelium of the proximal convoluted tubule of the nephron in the kidney has microvilli.

(iii) Columnar: Composed of a single layer of tall and slender cells. Their nuclei are located at the base. The free surface may have microvilli. They are found in the lining of the stomach and intestine and help in recreation and absorption. If the columnar or cuboidal cells bear cilia on their free surface they are called the ciliated epithelium. Their function is to move particles or mucus in a specific direction over the epithelium. They are mainly present in the inner surface of hollow organs like bronchioles and fallopian tubes.

Question 9.
Distinguish between

  1. Simple epithelium and compound epithelium
  2. Cardiac muscle and striated muscle
  3. Dense regular and dense irregular connective tissues
  4. Adipose and blood tissue
  5. Simple gland and compound gland.

Answer:
1. Difference between Simple epithelium and Compound epithelium
Simple epithelium:
Simple epithelium is composed of a single layer of cells and functions as a lining for body cavities, ducts, and tubes.
Compound epithelium:
The compound epithelium consists of two or more cell layers and has a protective function as it does in our skin.

2. Cardiac muscle and striated muscle
Cardiac muscle:

  • They occur in the heart wall only.
  • They form a continuous network.
  • They are short and cylindrical with truncated ends.
  • They are branched and have faint light and dark bands.
  • Oblique bridges and intercalated discs are present.
  • They have nerve supply from the brain and autonomic nervous system
  • They have numerous mitochondria and glycogen granules.
  • Their blood supply is abundant with deep penetrating capillaries.
  • They contract rapidly and never get fatigued.

Striated muscle:

  • They occur in the body wall, limb tongue, pharynx, and beginning of the esophagus.
  • They form bundles that are attached to the skeleton by ends.
  • They are long and cylindrical with blunt ends.
  • They are multinucleated and bounded by distinct sarcolemma.
  • They are unbranched and have alternating light and dark cross bands.
  • Oblique bridges and intercalated discs are absent.
  • They have nerve supply from the central nervous system.
  • They have numerous mitochondria and glycogen granules.
  • They have an abundant blood supply
  • They contract rapidly and get fatigued soon.

3. Dense regular and Dense irregular
Dense regular:
In the dense regular connective tissues, the collagen fibers are present in rows between many parallel bundles of fibers. Tendons, which attach one bone to another are examples of this tissue.
Dense irregular:
Dense irregular connective tissue has fibroblasts and many fibers (mostly collagen) that are oriented differently. This tissue is present in the skin. Cartilage, bones, and blood are various types of specialized connective tissues.

4. Adipose and blood tissue
Adipose tissue:
Adipose tissue is another type of loose connective tissue located mainly beneath the skin. The cells of this tissue are specialized to store fats. The excess nutrients that are not used immediately are converted into fats and are stored in this tissue.
Blood tissue:
Blood is a fluid connective tissue containing plasma, red blood cells, white blood cells, and platelets. It is the main circulating fluid that helps in the transport of various substances.

5. Simple gland and compound gland
Simple gland:
These glands have a single, un-branched duct. The simple glands may be simple tubular glands (eg. crypts of in the intestine), simple coiled tubular glands (eg. sweat glands), and simple alveolar glands also called acinus glands having flask-shaped secretory units (eg. mucus-secreting glands in the skin of a frog.
Compound gland:
These glands have a branched system of ducts. The compound glands may be compound tubular glands (eg. gastric glands of the stomach, Brunners’ glands of the intestine), Compound alveolar gland (eg. some sebaceous glands and salivary glands), and compound tubuloalveolar glands, having both tubular and alveolar secretory units (eg. Pancreas, functional mammary glands.)

Question 10.
Mark the odd one in each series:

(a) Areolar tissue; blood; neuron; tendon
Answer:
A neuron is not a connective tissue.

(b) RBC; WBC; platelets; cartilage
Answer:
Cartilage is not part of blood.

(c) Exocrine; endocrine; salivary gland; ligament
Answer:
A ligament is not part of the gland.

(d) Maxilla; mandible; labrum; antenna
Answer:
The antenna is not a masticating part of the cockroach.

(e) Protonema; mesothorax; metathorax; coxa
Answer:
Coxa is not part of the thorax.

KSEEB Solutions

Question 11.
Match the terms in column I with those in column II:

Column I – Column II

(a) Compound eplthellum – (i) Alimentary canal
(b) Compound eye – (ii) Cockroach
(c) Septal nephrldla – (iii) Skin
(d) Open circulatory – (iv) Mosaic vision
(e) Typhiosole – (v) Earthworm
(f) Osteocytes – (vi) Phallomere
(g) Genitalia – (vii) Bone
Answer:
a – (iii)
b – (iv)
c – (y)
d – (ii)
e – (i)
f – (vii)
g – (vi)

Question 12.
Mention briefly about the circulatory system of earthworm
Answer:
The circulatory system of the earthworm

  1. Earthworm consists of a closed circulatory system, which consists of the heart, blood vessels, and blood.
  2. Blood glands are present in the 4th, 5th, and 6“ segments of the body, they produce blood cells and hemoglobin which remain dissolved in plasma.
  3. 7th, 9th, 12th, and 13th segments contain four pairs of pulsatile hearts.
  4. Blood circulates in one direction, which is maintained by contractions of the heart.
  5. The alimentary canal, nerve cord, and body wall get blood from smaller blood vessels.
  6. Blood cells are phagocytic in nature.

Question 13.
Draw a neat diagram of the digestive system of the frog.
Answer:
1st PUC Biology Question Bank Chapter 7 Structural Organisation in Animals 4

Question 14.
Mention the function of the following:

  1. Ureters in frog
  2. Malpighian tubules
  3. Body wall in earthworm

Answer:
1. Ureters in frog: The elimination of nitrogenous wastes is carried out by a well-developed excretory system. The excretory system consists of a pair of kidneys, ureters, cloaca, and urinary bladder. These are compact, dark red and bean-like structures situated a little posteriorly in the body cavity on both sides of the vertebral column. Each kidney is composed of several structural and functional units called uriniferous tubules or nephrons.

Two ureters emerge from the kidneys in the male frogs. The ureters act as a urinogenital duct that opens into the cloaca. In females, the ureters and oviduct open separately in the cloaca. The thin-walled urinary bladder is present ventral to the rectum which also opens in the cloaca. They excrete urea and thus is a ureotelic animal. Excretory wastes are carried by blood into the kidney where it is separated and excreted.

2. Malpighian tubules: At the junction of midgut and hindgut is present another ring of 100-150 yellow colored thin filamentous Malpighian tubules. They help in the removal of excretory products from the hemolymph. The hindgut is broader than the midgut and is differentiated into ileum, colon, and rectum. The rectum opens out through the anus.

3. Body wall in earthworm: Integumentary nephridia, attached to the lining of the body wall of segment 3 to the last that opens on the body surface. Nephridia regulate the volume and composition of the body fluids. A nephridium starts out like a funnel that collects excess fluid from the coelomic chamber. The funnel connects with a tubular part of the nephridium which delivers the wastes through a pore to the surface in the body wall into the digestive tube.

1st PUC Biology Structural Organisation in Animals Additional Questions and Answers

1st PUC Biology Structural Organisation in Animals One Mark Questions

Question 1.
What do fibroblasts synthesize?
Answer:
Collagen and elastin fibres.

Question 2.
Name two kinds of filaments of microfibrils.
Answer:
Actin and Myosin filaments.

Question 3
Name the functional contractile unit of the muscle.
Answer:
Sarcomere.

Question 4.
Name the type of tissue that is most abundant in an animal body.
Answer:
Connective tissue.

Question 5.
Name the tissue which connects muscles to a bone.
Answer:
Tendon

Question 6.
Name one specialised connective tissue.
Answer:
Blood.

Question 7.
Where are blood cells manufactured in the bone?
Answer:
Bone marrow.

Question 8.
What name is given to the cells of cartilage?
Answer:
Chondrocytes

Question 9.
What technical term Is given to bone cells?
Answer:
Osteocytes.

Question 10.
Why are striated muscles called Skeletal muscles?
Answer:
Since striated muscles are attached to the bones, they are called skeletal muscles.

Question 11.
Why are smooth muscles called Involuntary muscles?
Answer:
Smooth muscles are called involuntary muscles because their functioning cannot be controlled by our will

Question 12.
Name the excretory organs of an earthworm.
Answer:
Nephridia.

Question 13.
How does a frog take in water?
Answer:
Frogs take in water through their skin.

Question 14.
How many cranial nerves does a frog have?
Answer:
Ten pairs.

Question 15.
Name the larva of a frog.
Answer:
Tadpole.

Question 16.
Name any 2 species of a cockroach?
Answer:
Periplaneta Americana
Blatta Orientalis.

Question 17.
What is an exoskeleton?
Answer:
‘The external body covering of the cock-roach is called Exoskeleton.

Question 18.
What are Malpighian tubules? (Belgaum 2004)
Answer:
The excretory organs of Insects (Cockroach) are called Malpighian tubules.

KSEEB Solutions

Question 19.
What Is a nymph? (Belgaum 2004)
Answer:
The larva of the cockroach is called Nymph.

Question 20.
What are mandibles?
Answer:
The jaws of cockroaches are called mandibles.

Question 21.
What type of mouthparts are seen in cock-roach? (B’lore South, B’lore North 2004)
Answer:
Mandibulate/ Chewing type.

Question 22.
Why is a cockroach called an omnivorous animal? (D. Kannada 2005)
Answer:
Cockroach feeds on all kinds of substances like leather, paper, cloth, etc., hence called omnivorous.

Question 23.
What are anal styles? (Tumkur 2005)
Answer:
Anal styles are unsegmented hair-like out-growths arising from the end of the abdomen in the male cockroach.

Question 24.
Write the scientific name of the cockroach.
Answer:
Periplaneta americana (Kolar 2005)

Question 25.
What is tergum? (Mandya 2005)
Answer:
The tergum is a dorsal chitinous plate of the exoskeleton of the cockroach.

1st PUC Biology Structural Organisation in Animals Two Marks Questions

Question 1.
What is pseudostratified epithelium? Mention one place where it is located in the human body.
Answer:
Pseudostratified Epithelium is the epithelial tissue made up of a single layer of columnar cells but appears two-layered because some cells are shorter than others and have their nuclei at different levels. It is located in the trachea and bronchi.

Question 2.
Name two proteins produced by fibroblasts. What are their functions?
Answer:
Collagen and Elastin.
These fibrous proteins provide strength, elasticity, and flexibility to the tissue.

Question 3.
What are exocrine glands? Name any two secretions of them.
Answer:
The glands which have ducts to pour their secretions into the respective site of action are called exocrine glands, e.g.: Salivary glands secrete saliva into the buccal cavity. Liver secretes bile into duodenum.

Question 4.
What are endocrine glands? Name their secretion.
Answer:
The glands which do not have ducts and pour their secretions directly into the blood are called endocrine glands. Their secretions are called hormones.

Question 5.
Differentiate between loose connective tissue and dense connective tissue.
Answer:

Loose connective tissue Dense connective tissue
The cells and fibres are loosely arranged in the matrix e.g.: Areolar tissue The cells and fibres are compactly arranged. e.g.: Tendon

Question 6.
Name the type of connective tissue that serves as a support framework for epithelium.
Mention the cell types in it.
Answer:
Areolar connective tissue serves as a support framework for epithelium. It contains mast cells, macrophages and fibroblasts.

Question 7.
Write four functions of bones.
Answer:

  • Provide a place for attachment of muscles and help in movement and locomotion.
  • Provide protection to internal organs
  • The long-bones of limbs serve the weight-bearing function.
  • They act as depot of calcium and phosphorous.

Question 8.
Mention four sites in adult human body, where cartilage is present.
Answer:

  • tip of nose
  • pinna of ear
  • between adjacent vertebrae in the vertebral column
  • joints in the limbs

Question 9.
Differentiate between smooth muscles and cardiac muscles.
Answer:

Smooth muscles Cardiae muscles
Cells are spindle shaped Cells are cylindrical
striations are absent striations are present
Intercalated discs are absent Intercalated discs are Present
don’t have automatic rtythmicity have automatic rtrythmicity

Question 10.
What is the main role of setae in an earthworm? What is their shape? Where are they attached to the body?
Answer:
The setae:-Their principal role is locomotion. They are S-shaped. They are embedded in the epidermal pits in the middle of each segment.

Question 11.
What is meant by cutaneous respiration? Name two groups of animal that show it.
Answer:
Respiration by the skin is known as cutaneous respiration. Frog and earthworm show that.

Question 12.
What is pulmonary respiration? Name two groups of animal that have it.
Answer:
Respiration by the lungs is called pulmonary respiration Reptiles, Mammals have that.

Question 13.
Mention any two differences between male and female cockroaches. (Bijapur, Udupi, Gulbarga 2005)
Answer:
Male cockroach

  • The 10th abdominal segment is rounded.
  • The terminal abdominal segment has anal styles and anal cerci.

Female Cockroach:

  • It is pointed in the female.
  • Anal styles are absent in females.

KSEEB Solutions

Question 14.
What are spiracles? How are they distributed in cockroaches? (B’lore North 2004)
Answer:
Spiracles are the openings of the respiratory system (trachea) in the cockroach. There are 10 pairs of spiracles of which two pairs are located in the thorax and eight pairs in the abdomen.

Question 15.
List the mouthparts of the Cockroach. (D. Kannada 2006)
Answer:
Labrum, Mandible, hypopharynx, maxillary palp (cardo, stipes, lacinia, galea) submentum, mentum, prementum, glossa, paraglossa, labial palp.

1st PUC Biology Structural Organisation in Animals Three Marks Questions

Question 1.
What are the three types of muscle tissue? Write two characteristic points about the structure of each of them.
Answer:
(i) Striated muscles

  • Cells are cylindrical and unbranched
  • They show alternate dark and light bands called striations.

(ii) Smooth muscles

  • cells are spindle-shaped
  • Striations are absent

(iii) Cardiac muscles

  • Cells are cylindrical and branched
  • Striations are faint

Question 2.
Name the fluid connective tissue in our body. What is its matrix called? Name the cell types present in it.
Answer:
Blood is the fluid connective tissue. Its matrix is called plasma cell types in blood.

  • Red blood corpuscles
  • White blood corpuscles
  • Platelets

Question 3.
Write three differences between bone and cartilage.
Answer:

Bone Cartilage
It is a solid, rigid, and strong connective tissue It is a solid, semi-rigid, and flexible connective tissue
Occur singly in a lacuna Occur in clusters of 2 or  3 in each lacuna
Matrix is deposited with salts of calcium and phosphorous No calcium and phosphorous salts are present in the matrix.

Question 4.
Answer the following:

(i) What is the function of nephridia?
Answer:
Nephridia regulate the volume and composition of the body fluid in the earthworm. They help in the excretion of wastes.

(ii) How many types of nephridia are found in the earthworm, based on their location?
Answer:
Three types of nephridia are found.

Question 5.
Describe the nervous system of an earth-worm.
Answer:
Brain is formed by the fusion of a pair of cerebral ganglia, it lies in the anterior and dorsal part of the third segment. It is connected to two sub-pharyngeal ganglia lying below the pharynx. A double ventral nerve cord runs up to the last segment. Ganglia are segmentally arranged on the nerve cord and they give nerves to the organs of that segment.

Question 6.
Mention the function of the following

(a) Ureters In frog
Answer:
They carry urine from kidneys to the cloaca. In males, it also conducts the sperms.

(b) Malphlglan tubules
Answer:
They are the excretory organs of a cockroach. They collect the nitrogenous wastes from the hemolymph and send them into the intestine.

(c) The body wall of earthworm
Answer:
The muscle layers help in locomotion. It has sensory/receptor cells. Mucus is secreted by certain cells of the body wall.

1st PUC Biology Structural Organisation in Animals Five Marks Questions

Question 1.
(i) Draw a labelled diagram of areolar connective tissue.
Answer:
1st PUC Biology Question Bank Chapter 7 Structural Organisation in Animals 5

(ii) Where is It found In the human body?
Answer:
It is found beneath the skin.

(iii) How does it differ from adipose tissue?
Answer:

Areolar tissue Adipose tissue
Adipocytes are absent Adipocytes are present
Most cells are present Mast cells are absent
It serves as a support framework for epithelium It synthesizes, stores, and metabolizes fat.

Answer in one word or one line.

(i) Give the common name of Periplaneta Americana
Answer:
Cockroach

(ii) How many spermathecae are found In earthworms?
Answer:
Four pairs.

(iii) What is the position of ovaries in a cockroach?
Answer:
A pair of ovaries extend between 4th and 6th segments.

(iv) How many segments are present in the abdomen of a cockroach?
Answer:
Ten segments

(v) Where do you find Malpighian Tubules?
Answer:
The junction between midgut and hindgut.

Question 3
Draw a neat labelled diagram of the digestive system of the cockroach. (B.North, Shimoga, Gulbarga, Belgaum, Chikmagalur 2004, D.Kannada, Hassan, Mysore, Kolar, M.Q.P. 2005, Udupi.06, 08, D.K. 06, 07, 08, Koppala, Tumkur. 05,08, U.Kannada 08, D.K. 2009)
Answer:
The digestive system mainly consists of the foregut, midgut, and hindgut. The foregut/stomodeum consists of the mouth, pharynx, oesophagus, crop, and gizzard. The mouth is situated anteriorly below the labrum and between the mandibles. It leads into the buccal cavity. The hypopharynx lies on the floor of the buccal cavity. The salivary receptacular duct opens behind the tongue.

1st PUC Biology Question Bank Chapter 7 Structural Organisation in Animals 6

The pharynx is a narrow tubular part from where the oesophagus arises. The oeophagus is narrow and connects the buccal cavity to the crop. The crop is a thin-walled sac, present in the whole of the thorax and serves as a reservoir for food storage. The midgut/mesenteron is a short narrow tube lined by glandular epithelium. It is the main organ of digestion and absorption. At the junction of gizzard and midgut, 6 – 8 short fingerlike hollow tubes arise called hepatic caecae.

The hindgut/proctodaeum is a long tube-like structure with 60 – 70 narrow thread-like yellow structures called Malpighian tubules. The hindgut is differentiated into an anterior short, narrow ileum, middle long wide coiled colon, and a terminal short dilated sac-like structure the rectum which opens to the exterior by the anus.

KSEEB Solutions

Question 4.
With the help of a neat labelled diagram Explain the nervous system of cockroach. (Bangalore South, Bangalore Rural, Mandya, Mysore, Udupi 2005, D.Kanaada 2011)
Answer:
1st PUC Biology Question Bank Chapter 7 Structural Organisation in Animals 7
The nervous system of the cockroach consists of the central and peripheral systems, The central nervous system is made of ganglia and nerve, cords, whereas the peripheral nervous system is made of nerves arising from the ganglia.

  • Supra oesophageal ganglion:- are a pair of ganglia found in the head & form the brain.
  • Circum oesophageal Connectives:-These are thick ends of nervous tissue arising from the base of the brain and called commissures.
  • Sub oesophageal ganglia:- are a pair of ganglia in the oesophagus. They give off several nerves to the mouthparts.
  • Ventral nerve end cord segmental ganglia:- The double ventral nerve cord arises from the base of the sub oesophageal ganglia and runs to the end of the body. There are nine segmental ganglia, of which three pairs are thoracic, six pairs in the abdomen i. e 1st five lie in the first five abdominal segments, the last is large & found farther behind.
  • The thoracic ganglia give out nerves to the muscles of legs and wings and abdominal ganglia give out nerves to abdominal muscles, heart, spiracles & reproductive organs.

Question 5.
Explain the mouthparts of Cockroach. (D. Kannada 2007)
Answer:
1st PUC Biology Question Bank Chapter 7 Structural Organisation in Animals 8
Mouthparts: On the ventral side of the head mouth is present. The appendages surrounding the mouth which are helpful in feeding are called the mouthparts or trophi. The mouthparts of cockroaches are chewing and biting type.

The mouthparts of the Cockroach include the labrum (upper lip), mandibles, maxillae, labium (lower lip) and hypopharynx (tongue).

(i) Labrum: This is also known as the upper lip. It is a small flap-like structure which covers the mouth dorsally. The inner surface of the labrum bears taste buds concerned with the tasting of the food material.

(ii) Mandibles: The mandibles are a pair of small triangular, stout unjointed sclerotized structures present on either side of the mouth. They have a toothed inner edge that helps in biting the food materials into small pieces. Hence treated as jaws.

(iii) Maxillae: A pair of maxillae are present beneath the mandibles and treated as additional jaws. Each maxilla is differentiated into a basal segment consisting of cardo and stipes, a terminal segment consisting of an outer larger part called galea and an inner stouter part called lacinia. The outer border of stipes bears a long five jointed maxillary palps which is a five jointed structure. The maxillae help in holding and pushing the food into the mouth during swallowing.

(iv) Labium: The labium or lower lip lies behind the maxillae. It consists of the proximal submentum, middle mentum, and distal bilobed prementum. The mentum possesses a pair of labial palps. The prementum bears a pair of outer paraglossae and a pair of inner glossae.

(v) Hypopharynx: This is also known as a lingua. It represents the tongue of the cockroach. It is a cylindrical and tubular structure present above the labium between maxillae. Common salivary receptacular duct opens at its base.

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