Case Study Questions Class 11 Biology Chapter 7 Structural Organisation in Animals
CBSE Class 11 Case Study Questions Biology Structural Organisation in Animals. Important Case Study Questions for Class 11 Board Exam Students. Here we have arranged some Important Case Base Questions for students who are searching for Paragraph Based Questions Structural Organisation in Animals.
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CBSE Case Study Questions Class 11 Biology Structural Organisation in Animals
CASE 1
Epithelial tissue is commonly called as epithelium. This tissue provides an external and internal covering of the body and organs. The cells are compactly packed with little intercellular matrix. There are two types of epithelial tissues namely simple epithelium and compound epithelium. Simple epithelium is composed of a single layer of cells and functions as a lining for body cavities, ducts, and tubes. The compound epithelium consists of two or more cell layers and has protective function as it does in our skin. On the basis of structural modification of the cells, simple epithelium is further divided into three types. These are (i) Squamous, (ii) Cuboidal, (iii) Columnar.
The squamous epithelium is 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 lungs and are involved in functions like forming a diffusion boundary.
The cuboidal epithelium is 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 Columnar is composed of a single layer of tall and slender cells. Their nuclei are located at the base. Free surface may have microvilli. They are found in the lining of stomach and intestine and help in secretion and absorption.
If the columnar or cuboidal cells bear cilia on their free surface they are called 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.
Some of the columnar or cuboidal cells get specialised for secretion and are called glandular epithelium. They are mainly of two types: unicellular, consisting of isolated glandular cells (goblet cells of the alimentary canal), and multicellular, consisting of cluster of cells (salivary gland).
Compound epithelium is made of more than one layer (multi-layered) of cells. Their main function is to provide protection against chemical and mechanical stresses. They cover the dry surface of the skin, the moist surface of buccal cavity, pharynx, inner lining of ducts of salivary glands and of pancreatic ducts.
All cells in epithelium are held together with little intercellular material. In nearly all animal tissues, specialised junctions provide both structural and functional links between its individual cells. Three types of cell junctions are found in the epithelium and other tissues. These are called as tight, adhering and gap junctions. Tight junctions help to stop substances from leaking across a tissue. Adhering junctions perform cementing to keep neighbouring cells together. Gap junctions facilitate the cells to communicate with each other by connecting the cytoplasm of adjoining cells, for rapid transfer of ions, small molecules and sometimes big molecule
1.) _________________ Junctionprovides attachment to keep neighbouring cells together and intact.
a) Tight junction
b) Adhering junctions
c) Gap junctions
d) All of the above
2.) ______________________Junctionfacilitate the communication between the adjacent cells.
a.) Tight junction
b) Adhering junctions
c) Gap junctions
d) All of the above
3.) Name the organ in which cilliated epithelium are found.Give the functions of cilia present in it.
4.) Write the name of organ or location where all three types of epithelium tissue serves some functions?
5.) Give the functions of tight junction and gap junctions.
Answer key
1.) b
2.) c
3.) They are mainly present in the inner surface of hollow organs like bronchioles and fallopian tubes. The function of cilia is to move particles or mucus or ova in a specific direction over the epithelium.
4.) On the basis of structural modification of the cells, simple epithelium is further divided into three types. These are Squamous,Cuboidal and Columnar
- Squamous epithelium :
It is found in the walls of blood vessels and air sacs of lungs and are involved in functions like forming a diffusion boundary.
- Cuboidal epithelium :
It is commonly found in ducts of glands and tubular parts of nephrons in kidneys and its main functions are secretion and absorption.
- The Columnar epithelium :
It is found in the lining of stomach and intestine and help in secretion and absorption.
5.) All cells in epithelium are held together with little intercellular material, called junction.
- Tight junctions help to stop substances from leaking across a tissue.
- Gap junctions facilitate the cells to communicate with each other by connecting the cytoplasm of adjoining cells, for rapid transfer of ions, small molecules and sometimes big molecule.
CASE 2
Connective tissues are most abundant and widely distributed in the body of complex animals. They are named connective tissues because of their special function of linking and supporting other tissues/organs of the body. They range from soft connective tissues to specialised types, which include cartilage, bone, adipose, and blood. In all connective tissues except blood, the cells secrete fibres of structural proteins called collagen or elastin. The fibres provide strength, elasticity and flexibility to the tissue. These cells also secrete modified polysaccharides, which accumulate between cells and fibres and act as matrix (ground substance). Connective tissues are classified into three types: (i) Loose connective tissue, (ii) Dense connective tissue and (iii) Specialised connective tissue
Loose connective tissue has cells and fibres loosely arranged in a semi-fluid ground substance, for example, areolar tissue present beneath the skin. Often it serves as a support framework for epithelium. It contains fibroblasts (cells that produce and secrete fibres), macrophages and mast cells. Adipose tissue is another type of loose connective tissue located mainly beneath the skin. The cells of this tissue are specialised to store fats. The excess of nutrients which are not used immediately are converted into fats and are stored in this tissue.
Fibres and fibroblasts are compactly packed in the dense connective tissues. Orientation of fibres show a regular or irregular pattern and are called dense regular and dense irregular tissues. In the dense regular connective tissues, the collagen fibres are present in rows between many parallel bundles of fibres. Tendons, which attach skeletal muscles to bones and ligaments which attach one bone to another are examples of this tissue. Dense irregular connective tissue has fibroblasts and many fibres (mostly collagen) that are oriented differently. This tissue is present in the skin.
Cartilage, bones and blood are various types of specialised connective tissues.
1.) The tissues which has cells with the presence of loosely arranged fibres in a semi-fluid ground substance are termed as
a) Dense connective tissue
b) Loose connective tissue
c) Loose arranged tissue
d) All of the above
2.) ___________ Tissue present just below the skin serves as a cementing framework for epithelium.
a.) Adipose tissue
b) Aeolic tissue
c) Areolar tissue
d) Fibroblast cells
3.) _________________tissues has collagen fibres present in rows between many parallel bundles of fibres.
a.) Dense regulated connective tissues
b) Dense regular connective tissues
c) Dense irregular connective tissues
d) Dense regularise connective tissues
4.) Name the tissue which is specialised to stores the skin fat. Give its function.
5.) Why connective tissue is named as connective tissue?
6.) What is fibroblasts?
Answer key
1.) b
2.) c
3.) b
4.) Adipose tissue is another type of loose connective tissue located mainly beneath the skin. The cells of this tissue are specialised to store fats. The excess of nutrients which are not used immediately are converted into fats and are stored in this tissue.
5.) Connective tissue widely distributed in the body of complex animals. They are named connective tissues because of their special function of linking and supporting other tissues, organs and organ system of the body.
6.) Fibroblasts are s cells that produce and secrete fibres. It produces collagen or elastin.
CASE 3
Each muscle is made of many long, cylindrical fibres arranged in parallel arrays. These fibres are composed of numerous fine fibrils, called myofibrils. Muscle fibres contract in response to stimulation, then relax and return to their uncontracted state in a coordinated fashion. Their action moves the body to adjust to the changes in the environment and to maintain the positions of the various parts of the body. In general, muscles play an active role in all the movements of the body. Muscles are of three types, skeletal, smooth, and cardiac. Skeletal muscle tissue is closely attached to skeletal bones. In a typical muscle such as the biceps, striated (striped) skeletal muscle fibres are bundled together in a parallel fashion.
The smooth muscle fibres taper at both ends and do not show striations. Cell junctions hold them together and they are bundled together in a connective tissue sheath. The wall of internal organs such as the blood vessels, stomach and intestine contains this type of muscle tissue. Smooth muscles are ‘involuntary’ as their functioning cannot be directly controlled. We usually are not able to make it contract merely by thinking about it as we can do with skeletal muscles.
Cardiac muscle tissue is a contractile tissue present only in the heart. Cell junctions fuse the plasma membranes of cardiac muscle cells and make them stick together (Figure 7.7c). Communication junctions (intercalated discs) at some fusion points allow the cells to contract as a unit, i.e., when one cell receives a signal to contract, its neighbours are also stimulated to contract.
1.) __________________ is the type of involuntary muscles
a) Smooth Muscles
b) Cardiac Muscles
c) Both a & b
d) Skeletal Muscle
2.) Identify correct statement
Statement 1 – Cardiac muscle tissue is a contractile tissue present only in the heart.
Statement 2 – The smooth muscle fibres taper at both ends and do not show striations.
Statement 3 – Each muscle is made of many long, cylindrical fibres arranged in parallel arrays.
Statement 4 – Skeletal muscle tissue is closely attached to skeletal bones.
a) Both 1 & 2
b) Only 3
c) Both 2 & 4
d) All of the above
3.) Define myofibrils.
4.) Give the classification or types of muscle tissue?
5.) Why smooth muscles and cardiac muscles are called as involuntary muscles
6.) Name the muscles type which shows tapered fibre at both ends without striations?
Answer key
1.) c
2.) d
3.) Myofibrils: Each muscle is made of many long, cylindrical fibres arranged in parallel arrays. These fibres are composed of numerous fine fibrils, called myofibrils.
4.) Muscles are of three types,
- Skeletal
- Smooth
- Cardiac
5.) Smooth muscles and cardiac muscles are called as involuntary muscles because their functioning cannot be directly controlled and regulated by us.
6.) Smooth muscle is the muscle type in which fibres are tapered at both ends and do not show striations.
CASE 4
Frogs can live both on land and in freshwater and belong to class Amphibia of phylum Chordata. The most common species of frog found in India is Rana tigrina.
Frogs do not have constant body temperature as their body temperature varies with the temperature of the environment. Such animals are called cold blooded or poikilotherms. Frogs have the ability to change the colour to hide them from their enemies (camouflage). This protective coloration is called mimicry. Frogs are not seen during peak summer and winter. During this period they take shelter in deep burrows to protect them from extreme heat and cold. This is known as summer sleep (aestivation) and winter sleep (hibernation) respectively.
The skin of frog is smooth and slippery due to the presence of mucus. The skin is always maintained in a moist condition. The colour of dorsal side of body is generally olive green with dark irregular spots. On the ventral side the skin is uniformly pale yellow. The frog never drinks water but absorb it through the skin. Body of a frog is divisible into head and trunk. A neck and tail are absent. Above the mouth, a pair of nostrils is present. Eyes are bulged and covered by a nictitating membrane that protects them while in water. On either side of eyes a membranous tympanum (ear) receives sound signals. The forelimbs and hind limbs help in swimming, walking, leaping and burrowing. The hind limbs end in five digits and they are larger and muscular than fore limbs that end in four digits. Feet have webbed digits that help in swimming. Frogs exhibit sexual dimorphism. Male frogs can be distinguished by the presence of sound producing vocal sacs and also a copulatory pad on the first digit of the fore limbs which are absent in female frogs.
1.) Frogs eyes are generally covered by _____________ which is protective in function.
a) Camouflage membrane
b) Copulatory membrane
c) Nictitating membrane
d) Tympanum membrane
2.) ___________________ is the unique and distinguishing as well as sexual character of male frog.
a) Presence of webbed digits
b) Presence of copulatory pad
c) Presence of Nictitating membrane
d) Presence of membranous tympanum
3.) What is mean by poikilotherms?
4.) Why Frogs are not seen during peak summer and winter?
5.) What is mean by camouflage and mimicry?
Answer key
1.) c
2.) b
3.) Animal in which body temperature varies with the variation in temperature of the environment those animals are called as poikilotherms. Such animals are also called as cold blooded animal.
4.) During this period they take shelter in deep burrows to protect them from extreme heat and cold. This is known as summer sleep (aestivation) and winter sleep (hibernation) respectively.
5.) The ability to change the colour to hide them from the enemies this is referred as camouflage, this protective coloration is called as mimicry.
CASE 5
Cartilage, bones and blood are types of specialised connective tissues. The intercellular material of cartilage is solid and pliable and resists compression. Cells of this tissue (chondrocytes) are enclosed in small cavities within the matrix secreted by them. Most of the cartilages in vertebrate embryos are replaced by bones in adults. Cartilage is present in the tip of nose, outer ear joints, between adjacent bones of the vertebral column, limbs and hands in adults.
Bones have a hard and non-pliable ground substance rich in calcium salts and collagen fibres which give bone its strength. It is the main tissue that provides structural frame to the body. Bones support and protect softer tissues and organs. The bone cells are called as osteocytes. The bone cells (osteocytes) are present in the spaces called lacunae. Limb bones, such as the long bones of the legs, serve weight-bearing functions. They also interact with skeletal muscles attached to them to bring about movements. The bone marrow in some bones is the site of production of blood cells.
Blood is a fluid connective tissue containing plasma, red blood cells (RBC), white blood cells (WBC) and platelets.It circulates throughout our body delivering oxygen and nutrients to various cells and tissues. It makes up 8% of our body weight. An average adult possesses around 5-6 litres of blood. There are many cellular structures in the composition of blood. When a sample of blood is spun in a centrifuge machine, they separate into the following constituents: Plasma, buffy coat and erythrocytes.
1.) Chondrocytes are ______________________.
a) Ligament tissue
b) Cell of the bones
c) Cell of the cartilage
d) None of the above
2.) _______________ is the spaces in which bone cells occurs.
a) Osteocytes
b) lacunae
c) Chondrocytes
d) Lacunaecyte
3.) Write the name of organ or location where cartilage tissue occurs in human body?
4.) Define Osteocytes & Lacunae.
5.) What gives the strength to the bone?
Answer key
1.) c
2.) b
3.) Cartilage present in the tip of nose, outer ear joints, between adjacent bones of the vertebral column, limbs and hands in adults.
4.) The bone cells are termed as osteocytes. The bone cells (osteocytes) are present in the spaces called as lacunae.
5.) Bones have a hard and non-pliable ground substance rich in calcium salts and collagen fibres which give bone its strength. It is the main tissue that provides structural frame to the body. Bones support and protect softer tissues and organs.