Important Questions Class 11 Biology Chapter 7 Structural Organisation in Animals
Important Questions Class 11 Biology Chapter 7 Structural Organisation in Animals
Structural Organisation in Animals is Chapter 7 of Class 11 Biology. It explains how cells form tissues, tissues form organs and organs form organ systems in animals. The chapter covers animal tissues such as epithelial tissue, and the body structure and organ systems of animals like the frog.
This page gives 12 important questions from Structural Organisation in Animals with clear answers prepared by Extramarks experts. The questions cover types of epithelial tissue, cellular components of blood, the alimentary canal of the cockroach, the digestive system of the frog and one-line questions on animal structure. Students can use them for school tests and CBSE (Central Board of Secondary Education) exam revision, and teachers and parents can use them for quick practice.
Q1. How many eggs does a female frog lay at a time?
Answer: 2500-3000.
Q2. Answer in one word or one line.
(i) Give the common name of Periplanata Americana.
(ii) How many spermathecae are found in earthworm?
(iii) What is the position of ovaries in cockroach?
(iv) How many segments are present in the abdomen of cockroach?
(v) Where do you find Malpighian tubules?
Answer: (i) Cockroach
(ii) Eight spermathecae are found in earthworm.
(iii) The two large ovaries are found lying laterally in the 2nd-6th abdominal segment.
(iv) 10 segments are present in the abdomen of both male and female cockroaches.
(v) Malpighian tubules are found at the junction of midgut and hindgut of a cockroach.
Q3. Answer the following:
(i) What is the function of nephridia?
(ii) How many types of nephridia are found in earthworm based on their location?
Answer: (i) Nephridia (sing.: nephridium) are the excretory organs of earthworm. They regulate the volume and composition of body fluids and excrete out the wastes of the body through a pore to the surface in the body.
(ii) Based on the location, three types of nephridia are found in earthworm:
a) Septal nephridia: They are present on both the sides of intersegmental septa of segment 15 to the last. They open into the intestine.
b) Integumentary nephridia: They are very minute and are hardly visible to the naked eye. They are attached to the lining of the body wall from segment 3 to the last. They open separately on the body surface.
c) Pharyngeal nephridia: They are present as three paired structures at the sides of the oesophagus in 4th, 5th and 6th segment.
Q4. Draw a labelled diagram of alimentary canal of a cockroach.
Answer: The diagram showing the alimentary canal of a cockroach is depicted below:
Q5. Distinguish between the followings
(a) Prostomium and peristomium
(b) Septal nephridium and pharyngeal nephridium
Answer: (a)
| Prostomium | Peristomium |
|---|---|
| It is the lobe at the anterior end of earthworm that serves as a covering for the mouth. | It is the first body segment of an earthworm. It is also known as buccal segment. |
| It is sensory in function. It also helps to crack open the soil when earthworm wants to enter in it. | It contains the mouth. |
(b)
| Septal nephridium | Pharyngeal nephridium |
|---|---|
| It is present on both sides of the intersegmental septa of segment 15 to the last one. | It is present as three paired tufts in the 4th, 5th and 6th segment. |
Q6. What are the cellular components of blood?
Answer: Blood is a fluid connective tissue. It contains red blood cells (RBCs), white blood cells (WBCs) and platelets (together constituting ~45% of volume) suspended in plasma (~55% of volume).
Red Blood Cells (erythrocytes): They are biconcave, large microscopic cells without nuclei. They carry oxygen from the lungs to the body’s tissue and take carbon dioxide back to the lungs to be exhaled out from the body.
White Blood Cells (leukocytes)- They exist in variable numbers and types (granulocytes and agranulocytes) but constitute only about 1% of blood's volume. Leukocytes are not limited to blood. Most are produced in bone marrow from the same kind of stem cells that produce red blood cells.
Platelets (thrombocytes)- They are small, colourless cell fragments without nuclei in the blood. Their main function is to interact with clotting proteins to stop or prevent bleeding.
Q7. What are the following and where do you find them in animal body.
(a) Chondrocytes
(b) Axons
(c) Ciliated epithelium
Answer: (a) Chondrocytes are cells of healthy cartilage tissue. They are found in the small cavities within the matrix secreted by them. Examples of cartilage tissue are the tip of the nose, outer ear joints, etc.
(b) The long slender projections of the nerve cells of nervous tissues are called axons. They help in sending messages by conducting electrical impulses away from the neuron’s cell body. They are present in the neural tissues like brain, spinal cord, nerves etc.
(c) When the columnar or cuboidal cells of epithelia bear cilia on their free surface, they are called the ciliated epithelium. They help in the movement of particles or mucus in a particular direction over the epithelium. They are present in the inner surface of hollow organs like bronchioles and fallopian tubes.
Q8. Distinguish between
(a) Simple epithelium and compound epithelium
(b) Cardiac muscle and striated muscle
(c) Dense regular and dense irregular connective tissues
(d) Adipose and blood tissue
(e) Simple gland and compound gland
Answer: (a)
| Simple epithelium | Compound epithelium |
|---|---|
| It is composed of a single layer of cells. | It is composed of two or more layers of cells. |
| It provides lining for body cavities, ducts and tubes of the body. | It provides protection against chemical and mechanical stresses. |
| It is involved in the process of secretion, diffusion, absorption, etc. | Its limited role is secretion and absorption due to the presence of multiple layers. |
| It is found in the ducts of glands, tubules of nephrons, walls of blood vessels, air sacs of lungs, the lining of alimentary canal etc. | It covers the dry skin surface, the moist surface of the buccal cavity, pharynx, salivary glands and pancreatic ducts. |
(b)
| Cardiac muscle | Striated muscle |
|---|---|
| It is a contractile tissue which has the ability to contract. | It is a bundle of fibres grouped together in a parallel fashion. |
| It is involuntary in nature. | It is voluntary in nature. |
| They are found only in the heart. | They are found in biceps, triceps and limbs. |
(c)
| Dense regular connective tissues | Dense irregular connective tissues |
|---|---|
| Fibres and fibroblasts show a regular orientation in dense regular connective tissues. Collagen fibres are present in rows between many parallel bundles of fibres. | Fibres (collagen) and fibroblasts show an irregular orientation in dense irregular connective tissues. |
| Example: Tendons and ligaments | Example: Skin |
(d)
| Adipose tissue | Blood tissue |
|---|---|
| It is a type of loose connective tissue, where adipocytes and fibres are loosely arranged. | It is a type of fluid connective tissue, composed of red blood cells, white blood cells and platelets in plasma. |
| It is semi-fluid in nature. | It is fluid in nature. |
| The cells are specialised to store fats. | The cells help in the transportation of food, wastes, gases and hormones from one part of the body to another. Also involved in defence and coagulation. |
(e)
| Simple gland | Compound gland |
|---|---|
| It is also known as a unicellular gland. | It is also known as a compound (multicellular) gland. |
| It consists of isolated glandular/secretory cells. | It consists of a cluster of glandular/secretory cells. |
| Example: Goblet cells of the alimentary canal. | Example: Salivary gland. |
Q9. Match the terms in column I with those in column II:
| Column I | Column II | ||
|---|---|---|---|
| (a) | Compound epithelium | (i) | Alimentary canal |
| (b) | Compound eye | (ii) | Cockroach |
| (c) | Septal nephridia | (iii) | Skin |
| (d) | Open circulatory system | (iv) | Mosaic view |
| (e) | Typhlosole | (v) | Earthworm |
| (f) | Osteocytes | (vi) | Phallomere |
| (g) | Genitalia | (vii) | Bone |
Answer:
| Column I | Column II | ||
|---|---|---|---|
| (a) | Compound epithelium | (iii) | Skin |
| (b) | Compound eye | (iv) | Mosaic view |
| (c) | Septal nephridia | (v) | Earthworm |
| (d) | Open circulatory system | (ii) | Cockroach |
| (e) | Typhlosole | (i) | Alimentary canal |
| (f) | Osteocytes | (vii) | Bone |
| (g) | Genitalia | (vi) | Phallomere |
Q10. Draw a neat diagram of digestive system of frog.
Answer: The diagram showing the digestive system of a frog is depicted below:
Q11. Mention the function of the following:
(a) Ureters in frog
(b) Malpighian tubules
(c) Body wall in earthworm
Answer: (a) The two ureters emerging from the kidneys of male frog act as a urinogenital duct that carry both urine and sperms. In female frogs, ureter carries only urine and excretes it out through cloaca.
(b) Malpighian tubules present at the junction of midgut and hindgut is involved in the removal of excretory products from the haemolymph of cockroaches.
(c) The body wall in earthworm performs the following functions:
- Helps retain water
- Helps in motion
- Helps in respiration (diffusion of gases)
- Helps in the contraction of the earthworm
- Secretes mucus which helps in locomotion and burrowing
- Also performs a sensory function
Q12. Describe various types of epithelial tissues with the help of labelled diagrams.
Answer: Epithelial tissue is the tissue provides lining to a body part and has a free surface either facing body fluid or the outside environment. There are two major types of epithelial tissues:
- Simple epithelium: It is composed of a single layer of cells and functions as a lining for body cavities, ducts and tubes. On the basis of structural modification, the simple epithelium is further divided into three types
- Squamous epithelium: Single thin layer of flattened cells with irregular boundaries mostly involved in the diffusion process. E.g. cells of walls of blood vessels, air sacs of lungs.
- Cuboidal epithelium: Single layer of cube-like cells. They are mostly found in ducts of glands and nephrons and are mainly involved in secretion and absorption.
- Columnar epithelium: Single layer of tall and slender cells with microvilli on the free surface. They are found in the lining of stomach and intestine and are involved in secretion and absorption.
Sometimes, cuboidal or columnar epithelium bear cilia (known as ciliated epithelium) and move particles in a specific direction or get specialized for secretion (known as glandular epithelium).
- Compound epithelium: It consists of two or more cell layers and has protective function e.g. our skin. They mainly provide protection against chemical and mechanical stresses. They form a dry protective layer of the skin, the moist surface of the buccal cavity, pharynx, inner lining of ducts of salivary glands and of pancreatic ducts.
Related Study Material on Extramarks
- Important Questions for Class 11 Biology Chapter 1 The Living World
- Important Questions for Class 11 Biology Chapter 2 Biological Classification
- Important Questions for Class 11 Biology Chapter 3 Plant Kingdom
- Important Questions for Class 11 Biology Chapter 4 Animal Kingdom
- Important Questions for Class 11 Biology Chapter 5 Morphology of Flowering Plants
- Important Questions for Class 11 Biology Chapter 6 Anatomy of Flowering Plants
- Important Questions for Class 11 Biology Chapter 8 Cell: The Unit of Life
- Important Questions for Class 11 Biology Chapter 9 Biomolecules
- Important Questions for Class 11 Biology Chapter 10 Cell Cycle and Cell Division
- Important Questions for Class 11 Biology Chapter 11 Photosynthesis in Higher Plants
- Important Questions for Class 11 Biology Chapter 12 Respiration in Plants
- Important Questions for Class 11 Biology Chapter 13 Plant Growth and Development
- Important Questions for Class 11 Biology Chapter 14 Breathing and Exchange of Gases
- Important Questions for Class 11 Biology Chapter 15 Body Fluids and Circulation
- Important Questions for Class 11 Biology Chapter 16 Excretory Products and their Elimination
- Important Questions for Class 11 Biology Chapter 17 Locomotion and Movement
- Important Questions for Class 11 Biology Chapter 18 Neural Control and Coordination
- Important Questions for Class 11 Biology Chapter 19 Chemical Coordination and Integration
Q.1Â Basement membrane is made up of?
Marks:1
Ans
Basement membrane is a delicate non-cellular layer made up of extra-cellular material that lies below the epithelium in contact with its basal surface.
Q.2 In human, nervous tissue is made up of neurons and neuroglia. Neuroglia
(a) provides support to neurons.
(b) provides protection to the body.
(c) transports impulses to the brain.
(d) carries impulses to the neurons.
Marks:1
Ans
Provides support to neurons.
Explanation:
Neuroglia makes up more than one half the volume of neural tissue in our body. They maintain homeostasis, provide support and protection for the neurons.
Q.3 Which of the following statements are correct for a muscle fibre?
1. A muscle fibre is uninucleated.
2. Sarcoplasmic reticulum stores calcium ions.
3. A muscle fibre is made up of a large number of muscle bundles.
4. The outer membrane of a muscle fibre is known as sarcolemma.Â
Marks:1
Ans
Each muscle is made of many long, cylindrical fibres arranged in parallel arrays. A muscle fiber is cylindrical and has more than one nucleus. A muscle fiber is a single cell that is made up of a bundle of myofibrils, filaments arranged in segments known as sarcomeres.
Q.4 Saliva of cockroach contains
Marks:1
Ans
Cockroaches have acinar salivary glands, consisting of secretory acini and a duct system. The saliva of cockroaches contains amylase.
Q.5 The body cavity of cockroach is?
Marks:1
Ans
Haemocoel is the cavity in which most of the major organs of the arthropod body are found. It is filled with the fluid haemolymph (the arthropod equivalent of blood), which is pumped by a heart. It circulates among the organs directly without the use of capillaries.