NCERT Solutions Class 11 Biology Chapter 7

NCERT Solutions for Class 11 Biology Chapter 7

Give a head start to your test preparation by accessing the NCERT Solutions, Class 11 Biology, Chapter 7, Structural Organisation in Animals from Extramarks. To provide a thorough study aid for all students, our subject specialists have solved the exercises in this chapter from the NCERT textbook. The NCERT Solutions for Class 11 Biology, Chapter 7, are available for free and considered an ideal study resource for last-minute revision. Students can actually use these solutions to prepare for different competitive examinations.

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

The first term’s NCERT Solutions for Class 11 Biology Chapter 7 Structural Organisation in Animals strive to provide students with complete answers to all of the problems in the NCERT Textbook. These NCERT Solutions for Class 11 have been updated to reflect the most recent CBSE term-by-term Syllabus 2022-23. Students must use numerous resources to broaden their horizons in order to do exceptionally well, which will be incredibly beneficial not only for the term – I assessments but also for their upcoming competitive exams.

These class 11 Biology chapter 7 NCERT solutions have been written by a team of specialists in an easy-to-understand and basic manner, ensuring a pleasant learning experience.

Also, these NCERT Solutions have been simplified for students by subject-matter experts at Extramarks. The experts who prepared these solutions have a broad understanding of Biology and have discussed all the concepts in an easy-to-understand manner. Students become familiar with these solutions in a short span of time because the information has been collected from the standard study resource, the NCERT textbook. Students can then begin their term – I test preparations.

Study Important Questions for Class 11 Biology Chapter 7 Structural Organisation In Animals

Q1. What is the common name of Periplaneta Americana?

A1. American Cockroach is the common name of Periplaneta Americana. It can be 34-53 cm long in the adult phase.

Q2. How many pairs of spermatheca are present in earthworms?

A2. Earthworms have four pairs of spermatheca located between the sixth and ninth segments. These help in receiving and storing spermatozoa at the time of copulation.

Q3. Where are the ovaries positioned in a cockroach?

A3. The ovaries are positioned between the 12th and 13th abdominal segments in a cockroach. These are present in pairs.

Q4. How many segments are there in the abdomen of a cockroach?

A4. There are ten segments in the abdomen of a cockroach. The number remains the same in both sexes.

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

The chapter discusses the structural organisation of animals in detail, including many facts and figures. The role of similar cells in a multicellular organism is covered in this chapter. Tissue is a collection of related cells that perform a specific function. Epithelial, Connective, Muscular, and Neural tissues are the four categories of animal tissues. The lining of several body parts is made up of epithelial tissue. Connective tissues, on the other hand, connect and support other tissues. All of these connective tissues are known to give animals’ bodies flexibility and suppleness.

Muscle tissue is made up of long cylindrical fibres that run parallel to one another. These fibres are made up of myofibrils, which are fibrils. A neuron is another name for neural tissue. The neuroglial cell is recognized for both protecting and supporting neurons. In multicellular organisms, all of these tissues are arranged to form numerous organ systems.

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

Class 11 Chapter 7 has a weightage of 5% in NEET. It has a weightage of 12% in school examinations. In the tests, the three chapters included in the unit are given equal weightage.

Benefits of NCERT Solutions For Class 11 Biology Chapter 7 Structural Organisation In Animals

Let’s have a look at the advantages of the NCERT Solutions by Extramarks.

  • Students can use the NCERT Solutions for Class 11 Biology Chapter 7 to learn about all the topics addressed in the chapter.
  • Our subject-matter experts have also solved the problems in accordance with CBSE guidelines so that students can learn how to write proper answers for their exams.

Q.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?

Ans-

(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.

Q.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?

Ans-

(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.

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

Ans-

The diagram showing the reproductive organs of an earthworm is depicted below:

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

Ans-

The diagram showing the alimentary canal of a cockroach is depicted below:

Q.5 Distinguish between the followings

(a) Prostomium and peristomium

(b) Septal nephridium and pharyngeal nephridium

Ans-

(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.

Q.6 What are the cellular components of blood?

Ans-

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.

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

(a) Chondrocytes

(b) Axons

(c) Ciliated epithelium

Ans-

(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.

Q.8 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

Ans-

(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.

Q.9 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

Ans-

(a) Neuron

(b) Cartilage

(c) Ligament

(d) Antennae

(e) Protonema

Q.10 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

 

Ans-

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

Q.11 Mention briefly about the circulatory system of earthworm.

Ans-

Characteristic features of the circulatory system of earthworm:

  • It consists of blood vessels, capillaries and heart.
  • It carries food, waste and respiratory gases along with coelomic fluid.
  • The blood vascular system is closed in nature and blood remains confined to heart and blood vessels.
  • The contractions of heart pump blood in one direction.
  • Smaller blood vessels supply the gut, nerve cord and the body wall.
  • Blood cells and haemoglobin are produced in blood glands present in 4th, 5th and 6th segment and then dissolved in the blood plasma. Blood cells are phagocytic in nature.

Q.12 Draw a neat diagram of digestive system of frog.

Ans-

The diagram showing the digestive system of a frog is depicted below:

Q.13 Mention the function of the following:

(a) Ureters in frog

(b) Malpighian tubules

(c) Body wall in earthworm

Ans-

(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

Q.14 Describe various types of epithelial tissues with the help of labelled diagrams.

Ans-

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:

  1. 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).

  1. 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.

Please register to view this section

FAQs (Frequently Asked Questions)

The cellular components of blood covered in Chapter 7 of NCERT Solutions for Class 11 Biology are –

  1. Red Blood Cells (RBC)
  2. White Blood Cells (WBC)
  3. Platelets

Students can use the solutions by Extramarks to have a better understanding of this idea. Experts create solutions for all textbook questions to assist students in quickly resolving their difficulties.

The past years’ question papers are available on Extramarks. Additionally, students can also access NCERT books, solution sets, mock tests, and sample papers on the website.

In earthworms, nephridia aids excretion and osmoregulation. In earthworms, there are three different forms of nephridia. The position of these can be used to classify them. The three types are:

  • Septal nephridia, which can be found on both sides of segment 15’s intersegmental septa.
  • Integumentary nephridia, which is generally attached to the body wall lining of segment 3.
  • Pharyngeal nephridia, which can be found in the fourth, fifth, and sixth segments.

Tissues are made up of a group of cell components that bunch together and perform the same function. Animal tissue is formed when animal cells come together or are grouped together. Features such as origin, function, and structure distinguish these tissues. Epithelial tissues, Muscular tissues, Connective tissues, and Nervous tissues are the four basic groups of tissues.

A simple epithelium consists of one layer of cells, whereas a compound epithelium consists of multiple layers of cells. In animals, the simple epithelium is involved in both secretion and absorption. The compound epithelium, on the other hand, is involved in the body’s protection process. The simple type can be found in the intestine as well as the lining of the stomach. Compound one, on the other hand, is found in the lining of the pharynx and buccal cavity.

Chondrocytes are the cells that are responsible for cartilage formation. Their shape is similar to that of a polygon. Chondrocytes are typically composed of collagen and proteoglycans. They can be found in any of the desired forms of AC in the articular cartilage of the intervertebral discs. These are only the cells found in the cartilage. The production and maintenance of the cartilage matrix is a function of chondrocytes.