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

NCERT Solutions For Class 11 Biology Chapter 7 PDF Free Download

NCERT Solutions for Class 11 Biology at BYJU’S aims at providing students with complete solutions to all the questions provided in the NCERT Class 11 textbook as per the board. In order to perform exceedingly well, students are required to refer to multiple resources to widen their horizon, which would be extremely helpful for students not only for the board examinations but also in their upcoming competitive exams.

These NCERT solutions for class 11 are skillfully crafted by a team of experts with the use of an easy-to-understand and simple language thus enabling a smooth learning experience. Students get acquainted with these solutions quickly as information has been extracted from the standard study tool, the textbook.

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NCERT Solution Class 11 Biology Chapter 7 Structural Organisation In Animals Part 1
NCERT Solution Class 11 Biology Chapter 7 Structural Organisation In Animals Part 2
NCERT Solution Class 11 Biology Chapter 7 Structural Organisation In Animals Part 3
NCERT Solution Class 11 Biology Chapter 7 Structural Organisation In Animals Part 4
NCERT Solution Class 11 Biology Chapter 7 Structural Organisation In Animals Part 5
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NCERT Solution Class 11 Biology Chapter 7 Structural Organisation In Animals Part 7
NCERT Solution Class 11 Biology Chapter 7 Structural Organisation In Animals Part 8
NCERT Solution Class 11 Biology Chapter 7 Structural Organisation In Animals Part 9

Access Answers of Biology NCERT class 11 Chapter 7- Structural Organization in Animals

1. 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?

Solution:

i) American cockroach

ii) 4 pairs of spermathecae are found in earthworm

iii) Two ovaries are found lying laterally around 2nd to 6th abdominal segments.

iv) 10 segments

v) Malpighian tubules are found at the junction of midgut and the hindgut of the alimentary canals of insects.

2. Answer the following:

(i) What is the function of nephridia?

(ii) How many types of nephridia are found in earthworm based on their location?

Solution:

i) Nephridia perform the function of excretion and osmoregulation in earthworms.

ii) Three types of nephridia are found in the earthworm based on their location they are:

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

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

Solution:

The diagram of reproductive organs of an earthworm is as follows:

Earthworm reproductive system

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

Solution:

The diagram of alimentary canal of a cockroach is as follows:

Cockroach ailmentry canal

5. Distinguish between the following:

(a) Prostomium and peristomium

(b) Septal nephridium and pharyngeal nephridium

Solution:

a) Prostomium and peristomium

The differences are as follows:

Prostomium

Peristomium

Small, fleshy lobe, serves as a covering for the mouth and as a wedge to force open cracks in the soil wherein the earthworm crawls.

It is the crescentic aperture at the anterior end of the first segment of the earthworm comprising the mouth

b) Septal nephridium and pharyngeal nephridium

Septal nephridium

Pharyngeal nephridium

Found at the anterior and posterior surface of septa occurring after segment 15 in earthworm

Found in three pairs in the 4th, 5th and 6th segments located on either side of the alimentary canal

Excretory matter is discharged into the lumen of the alimentary canal

Excretory matter is discharged into the gut, in the pharynx or buccal cavity

6. What are the cellular components of blood?

Solution:

The cellular components of blood are – Red blood cells (RBC), white blood cells (WBC) and platelets.

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

(a) Chondriocytes

(b) Axons

(c) Ciliated epithelium

Solution:

a) Chondriocytes are the cells of cartilage. Cartilage is present in the tip of nose, outer ear joints, between adjacent bones of the vertebral column, limbs and hands in adults. They are rounded, large and mature cells that are found occurring in clusters in the matrix of the cartilage.

b) An axon is a long slender projection of neuron or nerve cell. They are present throughout the body. They emerge from the cyton and are responsible to conduct nerve impulses away from the cell body. They terminate in a group of branches known as terminal arborisations.

c) If the columnar or cuboidal cells bear cilia on their free surface they are called ciliated epithelium. They are present in the inner surface of hollow organs like bronchioles and fallopian tubes. It comprises of fine vibratile cytoplasmic processes that are termed as cilia found on its free surface. This cilia is functional in trapping foreign substances and dust.

8. Describe various types of epithelial tissues with the help of labelled diagrams

Solution:

Epithelial tissues are found lining the body surface forming a protective surface. These cells are densely packed with very little intercellular matrix.

Various types of epithelial tissues are:

i) Simple epithelium:

It is single layer of cells which functions as a lining for body cavities, ducts, and tubes.

Based on the structural modifications of the cells, Simple epithelial cells are futher divided into 4 types:

  • Squamous epithelium
  • Simple epithelum made of single layer of flattened cell having irregular boundaries. Since their cells represent tiles of a floor, they are also referred to as pavement epithelium. They are found in the walls of blood vessels and air sacs of lungs. They are involved in excretion, protection, exchange of gases, secretion of coelomic fluid etc.

  • Cuboidal epithelium
  • Cuboidal epithelium is madeup of single layer of cube-like cells. They are commonly found in ducts of glands and tubular parts of nephrons in kidneys, and its primary functions are secretion and absorption of gamete formation.

  • Columnar epithelium
  • The columnar epithelium is made of single layer of tall and slender cells. They are found in the lining of stomach and intestine and help in secretion and absorption. The nuclei of these cells are elongated and found at different position. It aids in absorption and secretion.

  • Ciliated epithelium
  • If cuboidal or columnar epithelium has cilia then they are called as ciliated epithelium. They are present in the inner surface of hollow organs like fallopian tubes and bronchioles. Their function is to move particles in specific direction.

ii) Compound epithelim

The compound epithelium a layer of two or more cells with a protective function as it does in our skin. They are thick and strong compared to the simple epithelium as they comprise of two or more cell layers. It renders protection. They cover the dry skin surface, moist surface of the buccal cavity, inner lining of the ducts of pancreatic ducts and salivary ducts.

Simple and compound epithelium

9. 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

Solution:

a. Simple epithelium and compound epithelium

Simple epithelium

Compound epithelium

Composed of one layer of cells

Consisting of many layers of cells

They are involved in the function of absorption and secretion

They are involved in the protection

Present in the stomach lining and intestine

Present in the lining of the buccal cavity and pharynx.

Cells rest on basement membrane

Cells of the lowermost layer rest on the basement membrane

b. Cardiac muscle and striated muscle

Cardiac muscle

Striated muscle

They are involuntary in function, never gets fatigued

They are voluntary in function, hence gets fatigued sooner

They are found in heart

Found in triceps, limbs and biceps

Branched fibers

Unbranched fibers

Uninucleated

Multinucleated

c. Dense regular and dense irregular connective tissues

Dense regular connective

Dense irregular connective tissue

Collagen fibres are present in rows between parallel boundless fibres

Consists of Fibroblasts having several fibers that are differently oriented

Regular patterns of fibers observed

Irregular patterns of fibers observed

They are present in tendons and ligaments

They are present in the skin

d. Adipose and blood tissue

Adipose tissue

Blood tissue

It is made of collagen fibres, fibroblasts, macrophages and adipocytes

It consists of RBC, WBC, platelets and plasma

It is a loose connective tissue

It is a fluid connective tissue

Its function is to synthesise,store and metabolise the fats

Its function is to transport food, gases, hormones and waste.

Present beneath the skin

Present in the blood vessels

e. Simple gland and compound gland

Simple gland

Compound gland

They contain isolated glandular cells

Contains cluster of secretory cells

They are unicellular

They are multicellular

Ex: Goblet cells of the alimentary canal

Ex: salivary glands

10. Mark the odd one in each series:

(a) Areolar tissue; blood; neuron; tendon

(b) RBC; WBC; platelets; cartilage

(c) Exocrine; endocrine; salivary gland; ligament

(d) Maxilla; mandible; labrum; antennae

(e) Protonema; mesothorax; metathorax; coxa

Solution:

  1. The answer is neuron because it is not a connective tissue.
  2. The answer is cartilage because it is not part of blood.
  3. The answer is ligament because it is connective tissue, whereas the rest are glands.
  4. The answer is antennae because the rest other are parts of cockroach’s stomach.
  5. The answer is Protenema because it is thread-like chain of cells found in the life cycle of moss whereas others are theparts of segments of cockroach’s leg.

11. 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 vision

(e) Typhlosole

(v) Earthworm

(f) Osteocytes

(vi) Phallomere

(g) Genitalia

(vii) Bone

Solution:

Column I

Column II

(a) Compound epithelium

(iii) Skin

(b) Compound eye

(iv) Mosaic vision

(c) Septal nephridia

(v) Earthworm

(d) Open circulatory system

(ii) Cockroach

(e) Typhlosole

(i) Alimentary canal

(f) Osteocytes

(vii) Bone

(g) Genitalia

(vi) Phallomere

12. Mention briefly about the circulatory system of earthworm

Solution:

  • The earthworm has a closed circular system which comprises of blood vessels, capillaries and heart.
  • In earthworms, blood is confined to the heart and blood vessels as it is a closed circulatory system
  • Contraction keeps blood circulating in one direction.
  • Blood glands are present on the 4th, 5th and 6th segments. They produce blood cells, haemoglobin, that are dissolved in plasma of the blood.
  • Blood cells and are phagocytic.
  • Specilazied breathing system is absent hence the moist body surface helps in the respiratory exchange with their blood stream

13. Draw a neat diagram of digestive system of frog.

Solution:

The diagram is as below:

Frog digestive system

14. Mention the function of the following (a) Ureters in frog (b) Malpighian tubules (c) Body wall in earthworm

Solution:

  1. Ureters in frogActs as urinogenital duct which carries urine and sperm in the male frog.
  2. Malpighian tubulesMalpighian tubules are excretory organs in cockroaches.
  3. Body wall in earthworm – Helps in movement and burrowing

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

NCERT solutions for class 11 Biology Chapter 7 – Structural Organization in Animals is categorized under unit 2 – Structural organization in Plants and Animals. The total marks that this unit 2 constitutes is approximately 12 marks as per past trends, which is roughly 17% of the question paper. Therefore students are required to pay extra attention to this chapter as a wide range of questions appear from this unit.

Some of the types of questions that appear in the question paper are as follows:

  • Remembering: knowledge-based
  • Understanding
  • Application type
  • Higher-order thinking skills – Analysing and Synthesis

List of subtopics covered in Chapter 7- Structural Organization in Animals

Number

Subtopic

7.1

Animal Tissue

7.2

Organ and organ system

7.3

Earthworm

7.4

Cockroach

7.5

Frogs

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

In this chapter, students learn the complex animal tissues which are arranged in a particular proportion and pattern for the formation of an organ. These organs, in turn, carry out a similar functionality by their physical and chemical interaction which constitutes for the organ system. Cells, tissues, organs and organ system divide their work in such a way that exhibits division of labour, contributing to the survival of the body.

This chapter provides details about different parts with examples such as cockroach, earthworm, frogs etc. Details of the anatomy of different creatures enable students to understand the anatomical features in-depth, their morphological features

Key Features of NCERT Solutions for Class 11 Biology Chapter 7 – Structural Organization in Animals

  • NCERT solutions are solved and reviewed by a team of experts
  • Extensive coverage of fundamental concepts
  • Curriculum-inclined solutions
  • The best resource for the CBSE board exam preparation as well as competitive exam preparation
  • Easy to understand and use of a simple language

Frequently Asked Questions on Structural Organization in Animals

What is common name of Periplanata americana?

American cockroach

How many spermathecae are found in earthworm?

4 pairs of spermathecae are found in earthworm

How many segments are present in the abdomen of cockroach?

10 segments

Where do you find Malpighian tubules?

Malpighian tubules are found at the junction of midgut and the hindgut of the alimentary canals of insects.

What is the function of nephridia?

Nephridia perform the function of excretion and osmoregulation in earthworms.

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