NCERT Solutions for Class 11 Biology Chapter 7 - Structural Organisation In Animals

1. Give the common name of Periplaneta americana.

Ans: The common name of Periplaneta americana is the American cockroach which is 34-53 cm long in the adult phase.

2. How many spermathecae are found in earthworms?

Ans: There are four pairs of spermatheca present in the earthworms which are located between the sixth and the ninth segments and help in receiving and storing the spermatozoa during copulation.

3. What is the position of the ovaries in the cockroach?

Ans: The ovaries of cockroaches are located between the 12th and 13th abdominal segments and it is present in pairs.

4. How many segments are present in the abdomen of cockroaches?

Ans: There are ten segments present in the abdomen of cockroaches in both the sexes.

5. Where do you find malpighian tubules?

Ans: Malpighian tubules are part of the alimentary canal and it is the main excretory organ.

Short Answer Questions (2 Marks)

1. What is the function of nephridia?

Ans: Nephridia are the excretory organ of earthworm which is structurally coiled and segmentally arranged.

2. How many types of nephridia are found in earthworms based on their location? 

Ans: There are three types of nephridia present on earthworms.

(i) Septal Nephridia: It is located behind the 15th segment and is present on both sides of the intersegmental septa. As it is present from 15 to the last segment therefore it opens into the intestine.

(ii) Integumentary Nephridia: These are attached to the body wall lining from the third segment to the last segment which opens on the body surface.

(iii) Pharyngeal Nephridia: These nephridia are present on the sixth segment in the paired form of three tufts in the fourth, fifth, and sixth segments.

3. Draw a labeled diagram of the reproductive organs of an earthworm.

Ans:

4. Draw a labelled diagram of the alimentary canal of a cockroach.

Ans:

5. Distinguish between the following

1) Prostomium and Peristomium

Ans:

2) Septal nephridium and pharyngeal nephridium

6. What are the cellular components of blood?

Ans: Erythrocytes (RBCs), leucocytes (WBCs), and thrombocytes (platelets)are the cellular components of blood, which form 45% of the blood and are found in the remaining fluid portion, called plasma.

In mammals, the erythrocytes are biconcave colored cells that are devoid of the nucleus because it makes space for carrying and transporting respiratory gases.

The leukocytes which are known as white blood cells are nucleated cells and are divided into mainly two types, granulocytes (neutrophils, eosinophils, and basophils) and agranulocytes (lymphocytes and monocytes). All these leukocytes mainly help in destroying the foreign particles by their phagocytic nature.

The megakaryocytes of the bone produce thrombocytes which are cell fragments and it helps during blood coagulation.

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

1) Chondrocytes

Ans: Chondrocytes is an intercellular material of cartilages and it is found enclosed in small cavities of cartilages within the matrix.

2) Axons

Ans: Axons are part of neurons which are long, slender-like projections that help in carrying the nerve impulse from one neuron body to another.

3) Ciliated Epithelium

Ans: Ciliated epithelium is called when the columnar and cuboidal cells bear cilia on their free surface. It is present inside the bronchioles and fallopian tubes.

8. Describe various types of epithelial tissue with the help of a labeled diagram.

Ans:

Epithelial tissues are mainly of two types: simple epithelium and compound epithelium.

1. Simple epithelium is made up of single layers of cells and it is present on the lining of body cavities, ducts, and tubes.

Simple epithelium is again divided into squamous, cuboidal and columnar. The squamous epithelium is single-layered and flat and it is made up of cells with irregular boundaries. It helps in diffusion therefore present in walls of blood vessels and air sacs of lungs.

2. The cuboidal epithelium is made up of cube-shaped cells arranged in a single layer and helps in secretion and absorption in ducts of glands and nephrons of kidneys.

3. The columnar epithelium is long and slender cells present as a single layer that helps in absorption and secretion in the lining of the stomach and intestine. When columnar and cuboidal cells possess cilia they are called ciliated epithelium and that cilia help in the movement of particles. 

4. The compound epithelium is made up of two layers or more than two layers of cells and its most important function is to provide protection against chemical and mechanical stress. It covers all the dry surfaces of skin, pharynx surface, ducts of salivary glands, buccal cavity, and pancreatic duct.

9 Distinguish Between

1. Simple epithelium and compound epithelium

Ans: 

2. Cardiac Muscle and Striated Muscle

3. Dense Regular and Dense Irregular Connective Tissues

4. Adipose and Blood Tissue

5. Simple Glands and Compound Glands

10. Mark the odd one in each series:

1. Areolar tissue; blood; neuron; tendon

Ans: The neuron is the example of neural tissue whereas the rest are the examples of connective tissues

2. RBC; WBC; platelets; cartilage

Ans: Cartilage is a type of connective tissue whereas RBCs, WBCs, and platelets are the components of blood connective tissue.

3. Exocrine; endocrine; salivary gland; ligament

Ans: The ligament is a type of connective tissue whereas the rest are types of epithelial glands.

4. Maxilla; mandible; labrum; athorax; coxa

Ans: Antennae are present on the head of cockroaches whereas the maxilla, mandible, and labrum are present on the mouth or it is the parts of the mouth region.

5. Protonema; mesothorax; metathorax; coxa

Ans: Protonema is related to the life cycle of moss whereas Mesothorax, metathorax, and coxa are the parts of the legs of a cockroach.

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

Ans:

(a) Compound epithelium is present on the surface of skin therefore skin is an example of compound epithelium.

(b) The compound eye of cockroaches helps in mosaic vision.

(c) Septal nephridium is a part of the excretory organ of earthworm nephridia.

(d) Open circulatory systems are found in cockroaches where therefore blood vessels open into space.

(e) Typhlosole is an alimentary canal of earthworms and it increases the area of absorption.

(f) Bone is also known as osteocyte and it is a type of connective tissue.

(g) Phallomere is the external genitalia of cockroaches.

12. Mention briefly the circulatory system of earthworms.

Ans: The circulatory system of earthworms is of close type with the heart, capillaries, and blood vessels. The fourth, fifth, and sixth segments consist of blood glands and these blood glands produce blood plasma with dissolved blood cells and hemoglobin. The supply of blood takes place from the heart to all body parts by contraction of vessels and heart. In the nerve cord gut and body wall, the supply of blood takes place from small blood vessels.

13. Draw a neat diagram of the digestive system of frogs.

Ans:

14. Mention the function of the following

1. Ureters in Frog

Ans: Ureters in frogs: In a male frog the ureter carries both excretory matter and sperm, therefore, it is also known as the urogenital duct which opens into the cloaca whereas in females the ureter only carries excretory material.

2. Malpighian Tubules

Ans: Malpighian tubules: It is made up of glandular and ciliated epithelium and helps in the excretion of waste material in cockroaches.

3. Body Wall in Earthworm

Ans: In earthworms, the body wall is segmented which helps in movement and it also consists of secretory glands.

NCERT Solutions for Class 11 Biology Chapter 7 - Structural Organisation in Animals

The chapter offers detailed information about the structural organization in animals talking about diverse facts and figures. This PDF is the best resource for a quick study of the topics covered in the chapter.

The chapter covers the specific function as provided by similar cells in a  multicellular organism. This group of similar cells performing a particular function is known as tissue. The animal tissues can be divided into four types, Epithelial, Connective, Muscular, and Neural. The epithelial tissue provides the lining over some of the body parts. The connective tissues, on the other hand, link and support other types of tissues. All these connective tissues are known to provide flexibility as well as elasticity in the body of animals. 

The muscle tissues are basically made up of long kinds of cylindrical fibres that are placed parallel to each other. These fibres are made up of fibrils that are known as myofibrils. The neural tissue is also known as a neuron. The neuroglial cell is known to protect as well as support the neuron. All these tissues are organized to form various organ systems in different multicellular organisms. 

NCERT Solutions For Class 11 Biology Chapter 7 Structural Organisation In Animals: Weightage 

The Structural Organization In Animals Class 11 NCERT is included under Unit 2, in the NCERT textbook. The unit has a weightage of 5 per cent in the upcoming NEET exam while 12 per cent in the exams. The three chapters included in the unit get evenly distributed weightage in the exams. 

Important Concepts Covered in Chapter 7 - Structural Organisation in Animals

From this chapter, students will understand the complex animal tissues that are arranged in a specific proportion & pattern for the development of an organ. Find important concepts covered in this chapter from the below list:

• Animal Tissue

• Epithelial tissue

• Connective tissue

• Muscular tissue

• Nervous tissue

• Organ and organ system

An organ is made up of a group of tissues, and an organ system is a collection of organs that work to carry out one or more functions. Each organ is made up of at least one type of tissue. An organ system is a group of organs that work to carry out a specified function. Examples of organ systems include the excretory system, reproductive system, endocrine system, circulatory system, and respiratory system.

• Earthworm

• Cockroach

• Frogs

Benefits of NCERT Solutions for Class 11 Biology Chapter 7: Structural Organisation in Animals

• The solutions are curated by experts at Vedantu with detailed explanations.

• These solutions cover both the basic and advanced concepts of the chapter.

• All the solutions adhere to the curriculum. 

• Students can consider this as the material for competitive exams also. 

• The explanations are very clear as solutions are written in simple and easy to understand language. 

Conclusion

The NCERT Solutions for Chapter 7 Structural Organisation in Animals are important and must be studied by the students while preparing for their Class 11 CBSE exam. It is also important for competitive exams. This article covers NCERT Solutions for Class 11 Biology Chapter 7 Structural Organisation in Animals. The solutions are provided in easy-to-understand language as they are curated by Subject Experts.