NCERT Solutions for Class 11 Biology Chapter 21

NCERT Solutions Class 11 Biology Chapter 21 by Extramarks are one of the most crucial study materials that students can refer to, and prepare well for their exams. Subject matter experts with a considerable amount of experience have researched and prepared these solutions. The solutions comprise accurate answers, examples, and diagrams to ensure that students understand everything comprehensively. 

NCERT Solutions for Class 11 Biology Chapter 21 – Neural Control and Coordination

Access NCERT Solutions for Biology Class 12 Chapter 21 – Neural Control and Coordination

NCERT Biology Class 11 Neural Control and Coordination

Chapter 21 of Class 11 Biology covers different aspects of the human neural system. There are practice questions at the end of the chapter to help students revise and gauge their understanding of the concepts. The NCERT Solutions for Class 11 Biology Chapter 21 by Extramarks will help students solve these practice questions with a high level of accuracy. Prepared by subject matter experts, the NCERT Solutions for Chapter 21 Biology have simple language and good use of examples so that students understand each and everything without any confusion.

Class 11 Neural Control and Coordination NCERT Solutions

NCERT Class 11 Biology Chapter 21 talks about the neural system of a human body with absolute clarity. Mechanisms of neural coordination such as the physiology of reflex action, the transmission of nerve impulses, impulse conduction across a synapse, reflex arc, and central neuron system are covered in the chapter.

The Forebrain, Hindbrain, Midbrain, spinal cord, peripheral nervous system, and autonomic nervous system which are all part of the central nervous system are discussed in this chapter. Sense organs like ears and eyes are one of the important topics of this chapter as well. This chapter talks about the mechanisms of impulse conduction, vision, and hearing in great detail. 

All possible questions that can be asked from this chapter are covered in Biology Class 11 NCERT Solutions Chapter 21, which is why referring to these solutions will surely help students in scoring well. 

CBSE Class 11 Biology Chapter 21 NCERT Solutions – Marks Distribution

NCERT Solutions Class 11 Biology Chapter 21 by Extramarks serve as an excellent reference material for Class 11 students. It helps them in understanding the format to answer these questions. Chapter 21 – Neural Control and Coordination comes under Unit V – Human Physiology. Students can expect a total of 18 marks from Unit V. Therefore, they must refer to NCERT Solutions by Extramarks to score better in the subject.

Benefits of NCERT Biology Class 11 Chapter 21 

Here are some of the reasons to refer to NCERT Solutions for Biology Class 11 Chapter 21:

  • The solutions have answers to all the questions in the NCERT Class 11 Biology textbook.
  • The solutions are prepared by subject-matter experts.
  • The solutions are prepared as per CBSE guidelines.
  • Solutions can be accessed online and offline. 

Related Questions

Excess secretion of growth hormone in adults leads to__________.

  1. A) Acromegaly
  2. B) Goitre
  3. C) Gigantism
  4. D) Dwarfism

Answer: A) Acromegaly

Explanation: Excessive growth occurs due to the overproduction of growth hormone. This condition in children is known as gigantism while in adults it is known as acromegaly. A noncancerous (benign) pituitary tumour is generally the cause of the overproduction of growth hormone. 

Lathyrism is caused by excessive consumption of

  1. A) Khesari dal
  2. B) Mustard oil
  3. C) Polished rice
  4. D) Mushrooms

Answer: A) Khesari dal

Explanation: Lathyrism is a neuronal disorder. This disease leads to lower-limb paralysis. Excessive consumption of Khesari dal can cause Lathyrism. The disease has been named on the scientific name of the Khesari dal, i.e. Lathyrus sativus. This Khesari dal had been banned for years in India due to its link to this disorder.

Which is an example of positive feedback?

  1. A) Seasonal growth
  2. B) Vessel diameter and blood pressure
  3. C) Allosteric inhibition of enzymes
  4. D) Both A and B.

Answer: A) Seasonal Growth

Explanation: The positive feedback mechanism is one that involves the enhancement of the original stimulus by the end product. Seasonal growth is an example of positive feedback in the control of population. 

A poisonous lizard is ___________________.

  1. A) Heloderma
  2. B) Agkistrodon
  3. C) Chamaeleon
  4. D) Varanus

Answer: A) Heloderma

Explanation: Venomous lizards are a part of the genus Heloderma which is the only genus of the family Helodermatidae. The family’s members are venomous. Their venom glands are not located in their upper jaws like snakes, instead, their venom glands can be found in their lower jaws. Heloderma do not have the musculature that enables them to inject venom like snakes. The venom in them is generally utilised for defence and is not of much use in capturing prey as getting the venom into the flesh of the prey would require chewing it. 

A person who shows unpredictable moods, outbursts of emotions, quarrelsome behaviour, and conflicts with others is suffering from

  1. A) Borderline Personality Disorder (BPD)
  2. B) Mood disorder
  3. C) Addiction disorder
  4. D) Schizophrenia

Answer: A) Borderline Personality disorder (BPD)

Explanation: Borderline personality disorder is a disorder that causes an individual to have an emotionally unstable personality. It is a serious mental illness that influences the functioning of a person’s everyday life. Self-image issues, instability in relationships, and issues in dealing with behaviour and emotions are BPD’s main features. A person who has BPD suffers from quarrelsome behaviour, mood swings or unpredictable moods, and conflicts.

All cranial nerves are related to parasympathetic nerve fibres except

  1. A) Oculomotor
  2. B) Facial
  3. C) Accessory spinal
  4. D) Vagus

Answer: C) Accessory Spinal

Explanation: Parasympathetic nervous system’s nerve fibres emerge from the central nervous system. Several cranial nerves, especially the facial nerve, vagus nerve, oculomotor nerve, and the glossopharyngeal nerve, are a part of specific nerves. The parasympathetic system is normally said to have craniosacral outflow due to its location. The central nervous system provides motor innervation to the two neck muscles – the trapezius muscle and the sternocleidomastoid muscle – through the spinal accessory nerve. Lower motor neurons which are located in the spinal cord’s upper segment form the fibres by which the spinal accessory nerve is formed. The cluster of neurons is referred to as the spinal accessory nucleus. The spinal accessory nucleus is located in the anterior horn’s (found in the spinal cord) posterolateral aspect. In contrast to this, most other motor neuron cell bodies are found in the anterior horn of the spinal cord.

Name the primary and secondary lymphoid organs.

Bone marrow and Thymus form the primary lymphoid organs. These are the organs where immature lymphocytes mature into antigen-sensitive lymphocytes. Lymph nodes, spleen, tonsils, Peyer’s patches, Mucosa-associated Lymphoid Tissue (MALT), and other specialised zones are a part of the secondary lymphoid organs. 

Which signals will get interrupted in case of a spinal cord injury?

Signals coming from the nerves along with signals coming to the receptors will be interrupted if one suffers a spinal cord injury.

FAQs (Frequently Asked Questions)

The various organs in the body interacting and complementing each other’s functions implies the coordination of organs. Organs work in a synchronised manner, i.e. they do not work independently. The neural system and endocrine system of the human body are what jointly integrate and coordinate all the activities of the organs in the human body in order to make them function in a synchronised manner. This is known as neural coordination. This coordination is fast and short-spanned. An organised network of point-to-point connections is provided by the neural system for quick coordination. A network of nerves in the body aids in this connection. 

The central processing organ of the body that acts as the ‘control and command system’ is called the brain. The skull guards it and three membranes called cranial meninges cover it. The three membranes include the outer layer which is called the dura mater, the middle layer called arachnoid, and the inner layer called the pia mater. The dura mater is a tough and fibrous membrane, the arachnoid is fragile and light, and the pia mater is an expansion of the brain tissue. The pia mater is a vascular membrane of the brain and is richly supplied by the blood. The Forebrain, the Hindbrain, and the Midbrain are the three sections of the brain. 

The human neural system consists of two parts, namely the central neural system and the peripheral neural system. The brain and the spinal cord make up the central neural system, therefore, control of the body and mind are this system’s main function. The peripheral neural system is a kind of nervous system. It executes the task of providing information to the entire body. This system plays a role outside the spinal cord and brain.  

Extramarks has NCERT Solutions Class 11 Biology Chapter 21 – Neural Control and Coordination available on its site. The solutions can also be accessed through its app. These are a reliable source of reference that one can avail The multiple benefits offered by Biology Class 11 NCERT Solutions Chapter 21 are:

  • The solutions have answers to all the questions that are given in the NCERT textbook.
  • Students can refer to the solutions online and offline.
  • The solutions have answers written in simple language and explained with the help of examples and diagrams.

Give a brief about the structure of the human ear.

The outer ear, the middle ear, and the inner ear are the three parts that form the structure of the human ear. The outer ear consists of an auricle or a pinna (which is a visible portion). The middle ear has three tiny bones known as malleus, incus, and stapes while the inner ear encompasses vestibular apparatus and snail-shell-like cochlea which are two distinct functional units.

Write a short note on reflex action. 

A sudden and involuntary response to stimuli is known as a reflex action. Immediate action is taken in response to a stimulus without much thought of the outcome. The immediate withdrawal of your hand from a pan that is too hot is an example of this. Reflex action kicks in to minimise the damage that can be caused to the body.