CBSE Class 11

CBSE Class 11

The Portrait of a Lady Important Extra Questions and Answers Class 11 English Hornbill

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Here we are providing The Portrait of a Lady Important Extra Questions and Answers Class 11 English Hornbill, Extra Questions for Class 11 English was designed by subject expert teachers.

The Portrait of a Lady Important Extra Questions and Answers Class 11 English Hornbill

The Portrait of a Lady Extra Questions and Answers Short Answer Type

Question 1.
Why was it hard for the author to believe that the grandmother was once young and pretty?
Answer:
It was difficult for the author to believe that his grandmother was once young and pretty. In fact, the thought was almost revolting. He had seen her old for the last twenty years. He felt she could age no further. The very thought of her playing games as a child seemed quite absurd and undignified.

Question 2.
The grandmother has been portrayed as a very religious lady. What details in the story create this impression?
Answer:
The author recalls his grandmother as a very religious woman. He remembers her hobbling about the house, telling the beads of her rosary. He recalls her morning prayers and her reading scriptures inside the temple. The author recounts how, during the last few days, she spent all her time praying.

Question 3.
The grandmother had a divine beauty. How does the author bring it out?
Answer:
The grandmother was not pretty but had a divine beauty. She dressed in spotless white. Her silver locks were scattered untidily over her pale, puckered face, and her lips constantly moved in an inaudible prayer. The author describes her “like the winter landscape in the mountains”a personification of “serenity, breathing peace and contentment.”

Question 4.
What proofs do you find of friendship between the grandmother and grandson in the story?
Answer:
The grandmother and grandson were good friends. She got him ready and walked him to and back from school. In the city, they shared a common bedroom. The author’s grandmother saw him off, silently, but kissing him on his forehead, when he went abroad and celebrated his return five years later.

Question 5.
The grandmother was a kind-hearted woman. Give examples in support of your answer.
Answer:
The grandmother was a kind-hearted woman. On her way back from school, she would feed the village dogs with stale chapattis. In the city, when she could not move out, she took to feeding sparrows that came and perched on her legs, shoulders, and head.

Question 6.
“This was the turning point in our friendship.” What was the turning point?
Answer:
The turning point in the friendship arrived when they shifted to the city. They saw less of each other as she could neither accompany him to school, nor understand English. She did not believe in science. She could not keep pace with the author’s modem education that he received in the city school.

Question 7.
Draw a comparison between the author’s village school education and city school education.
Answer:
The village school was attached to a temple and the students were taught the alphabet and morning prayers. The author and his grandmother walked to the school in the village. However, in the city he went by the school bus. He was taught science and English but not taught about god. He was also taught music.

Question 8.
What was the happiest moment of the day for the grandmother?
Answer:
The happiest moment of the day for the grandmother in the city was when she was feeding the sparrows. They perched on her legs, shoulders, and head but she never shooed them away.

Question 9.
What was ‘the last sign’ of physical contact between the author and the grandmother? Why did the author think that to be the last physical contact?
Answer:
The author was going abroad for five years. His grandmother kissed his forehead. He presumed this as the last sign of physical contact between them. He feared that she would not survive till he returned since he was going away for five years.

Question 10.
Everybody including the sparrows mourned the grandmother’s death. Elaborate.
Answer:
When the grandmother died, thousands of sparrows collected and sat in the courtyard. There was no chirruping. When the author’s mother threw some breadcrumbs for them, they took no notice of the breadcrumbs. They were full of grief at her death and flew away quietly after the cremation.

Question 11.
Describe the author’s grandfather as he looked in his portrait.
Answer:
In the portrait, the grandfather was dressed in a big turban and loose-fitting clothes. His long white beard covered the best part of his chest and he looked at least a hundred years old. He looked grandfatherly to the author; someone who could never have been young.

Question 12.
How does the author describe his grandmother?
Answer:
The author describes his grandmother as short, old, fat and slightly bent. To him, she looked the same for twenty years. It was difficult for him to imagine her young and pretty. But he found a beauty in her old age, like the serene winter landscape.

Question 13.
How does the author react to the idea of the grandmother being young at a point of time and playing games?
Answer:
The author could not conceive his grandmother as young and pretty, and playing games as a little girl. To him, it was like one of the myths and fables she told him.

Question 14.
How did the grandmother prepare the author for going to school?
Answer:
The grandmother woke him up each morning, bathed him, dressed him and got him ready for school. There after, she plastered his wooden slate, gave him breakfast and walked him to school. While the author sat in the veranda learning the alphabet and morning prayers, the grandmother sat inside the temple reading scriptures.

Question 15.
Why was the grandmother distressed by the education imparted in the city school?
Answer:
The grandmother disapproved of the author’s education in the English school; they were taught science. She could not understand English and did not believe in science. It made her unhappy that they were not taught about god. The music lessons in school made her unhappier as she felt it was not meant for the gentle folk.

Question 16.
How did the grandmother react to the fact that the author was being given music lessons? Why?
Answer:
The grandson’s learning music in school made her unhappy as she felt it was not meant for the gentle folk. For her, music had associations with beggars and harlots. She almost stopped speaking to the author.

Question 17.
The grandmother’s reception and send off of her grandson were very touching. Comment.
Answer:
When the writer went abroad, the grandmother saw him off at the railway station, silently praying and telling her beads, and she kissed his forehead. When he returned, she expressed her joy by collecting women from the neighbourhood, beating the drum and singing for hours of the homecoming of warriors. For the first time she missed her prayers.

Question 18.
When the grandmother was taken ill, how were her views different from the doctor’s?
Answer:
When the grandmother was taken ill, the doctor felt it was mild fever and would go. But the grandmother thought differently. She felt her end was near. She refused to waste any more time talking instead of spending it in prayers as she sensed that only a few hours remained before her life came to an end.

Question 19.
When people are pious and good, even nature mourns their death. Justify.
Answer:
When the grandmother died, the sparrows, along with the writer’s family, mourned her death. Thousands of sparrows came and sat quietly all around her dead body. The writer’s mother threw breadcrumbs but the sparrows took no notice of them. After her cremation they flew without touching the crumbs.

Question 20.
How did the grandmother spend her day in the city?
Answer:
The grandmother spent her day from sunrise to sunset at her spinning wheel. She sat spinning and reciting her prayers. It was only in the afternoon that she relaxed for a while to feed the sparrows.

The Portrait of a Lady Extra Questions and Answers Long Answer Type

Question 1.
Elaborate on the beautiful bond of love and friendship between the author and his grandmother.
Answer:
When the author was still young, his parents left for the city leaving him to the care of his grandmother. They were good friends. She woke him up each morning, bathed him, dressed him, plastered his wooden slate, gave him breakfast and walked him to school. While he sat in the veranda learning, the grandmother sat inside the temple reading scriptures.

When they settled in the city, they shared a common bedroom. When the writer was going abroad, she went to the railway station to see him off but did not speak a word, only kissed his forehead. The writer cherished this as their last physical contact as he was going away for five years. But his grandmother was there to receive him back. In the evening, she collected women from the neighbourhood and beat the drum and sang for hours of the homecoming of the warriors. For the first time she missed her prayers.

Question 2.
The grandmother was not pretty but beautiful. How?
Answer:
The grandmother was short, old, fat and slightly bent. For the last twenty years she looked the same and to the author she seemed too old to age further. It was difficult for him to imagine that she could have been young and pretty. But to him, she was beautiful in a pristine and peaceful way. He remembered her telling the beads of her rosary, untiringly.

Her silver locks lay scattered untidily over her pale, puckered face, and her lips constantly moved in an inaudible prayer. She was like the winter landscape in the mountains, serene and content.

Question 3.
Discuss the relevance of the title ‘The Portrait of a Lady’.
Answer:
Khushwant Singh draws a heart-warming pen-portrait of his grandmother whom he loved and admired. Though not pretty, she was beautiful to the author’s perception. Telling the beads of her rosary while her lips constantly moved in an inaudible prayer, she was like the winter landscape in the mountains serene and content. She shared a special relationship with the author.

She got him ready and walked him to and from school. White he sat in the veranda learning, his grandmother sat inside the temple reading scriptures. The writer recounts his memories of his grandmother when he went abroad and how on his return she collected women from the neighbourhood and beat the drum and sang for hours of the homecoming of the warriors.

For the first time, she missed her prayers. She was a pious soul, who cared for the family, and even dogs and sparrows; her death was mourned by all including the sparrows. The writer, through his portrayal, makes the old lady endearing and unforgettable.

Question 4.
From a foster mother in the village to a lonely old lady in the city describe the grandmother’s journey through the later part of her life.
Answer:
When Khushwant Singh was still young, his parents left for the city leaving him to the care of his grandmother. They were good friends. His grandmother tended to him, got him ready and walked him to . school. While Khushwant Singh and the other children sat in the school’s veranda, learning, his grandmother sat inside the attached temple, reading scriptures.

In the city, their friendship underwent a change. The only thing that remained unchanged was their common bedroom. She could not accompany him to school as he went by the school bus. His grandmother did not understand or approve of his ‘city education’ and their communication deteriorated further. Later, when he went to the university, he got a separate room and this severed their bond further. She then spent her day from sunrise to sunset at her spinning wheel. She sat spinning and reciting her prayers. It was only in the afternoon that she relaxed for a while to feed the sparrows.

Question 5.
Write a character sketch of the author’s grandmother using the following words: affectionate, caring, kind and benevolent, religious, a strong woman.
Answer:
The author’s grandmother was not pretty but to the author she was a beautiful woman an embodiment of serenity and contentment. She was a pious and a religious lady who was always telling beads of her rosary and her lips constantly moved in inaudible prayer. She was an affectionate and a caring woman. She shared a special relationship with the author.

She woke him up each morning, bathed him, dressed him, plastered his wooden slate, gave him breakfast and walked him to school. Her kindness and benevolence extended to the dogs and sparrows as well, whom she fed dutifully. She was a strong woman, who did not show any emotion when the author was going abroad but when he returned, she collected women from the neighbourhood and beat the drum and sang for hours of the homecoming of warriors.

Question 6.
The grandmother herself was not formally educated but was serious about the author’s education. How does the text support this?
Answer:
The grandmother was not formally educated but was serious about the author’s education. She could read the scriptures. She realized the value of education and did not let the author miss school. She woke him up each morning, bathed him, dressed him, plastered his wooden slate, gave him breakfast and walked him to school where he was taught the alphabet and morning prayers. While he sat in the veranda learning, the grandmother read her scriptures.

In the city, she could not accompany him to school as he went by the school bus. He was now in an English school, where they taught science. She could not understand English and did not believe in science. The fact that they were not taught about god made her unhappy. Khushwant Singh’s music lessons in school upset her over its lewd associations. She took an interest in the author’s education.

Question 7.
Gradually the author and the grandmother saw less of each other and their friendship was broken. Was the distancing deliberate or due to
the demands of the situation?
Answer:
When the author was a young boy, his parents shifted to the city leaving him with his grandmother. They were good friends. She was with him through the day and even accompanied him to and from school.

But when his parents had settled in the city, they sent for them. This proved to be a turning point in their friendship. The only thing that remained unchanged was their common bedroom. She could not accompany him to school as he went by the school bus. He was now in an English school, where they taught science.

She could not understand English and did not believe in science. The fact that they were not taught about god made her unhappy. His music lessons in school made her feel worse. But it was when he went to the university and got a separate room and that their ties were severed further. This was not deliberate, but the situations adversely affected their relationship.

NCERT Exemplar Solutions for Class 11 Biology Chapter 22 Chemical Coordination and Integration

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NCERT Exemplar Solutions for Class 11 Biology Chapter 22 Chemical Coordination and Integration

These Solutions are part of NCERT Solutions for Class 11 Biology. Here we have given NCERT Exemplar Solutions for Class 11 Biology Chapter 22 Chemical Coordination and Integration.

VERY SHORT ANSWER QUESTIONS

Question 1.
Which of the two adrenocortial layers, zona glomerulosa and zona reticularis lies outside enveloping the other?
Solution:
Zona glomerulosa envelops zona reticularis from the outside.

Question 2.
What is erythropoiesis? Which hormone stimulates it?
Solution:
The process of formation of RBC is Erythropoiesis. Erythropoietin, a Peptide hormone secreted from the juxtaglomerular cells of kidney stimulates erythropoiesis.

Question 3.
Name the only hormone secreted by pars intermedia of the pituitary gland.
Solution:
The only hormone secreted by Pars intermedia ^ of pituitary gland is Melanocyte Stimulating hormone (MSH). This hormone causes dispersal of pigment granules in the pigment cells, which darken the colour in certain animals like fishes and amphibians.

Question 4.
Name the endocrine gland that produces calcitonin and mention the role played by this ‘ hormone.
Solution:
Calcitonin/thyrocalcitonin linear polypeptide hormone comprising of 32 amino acids that is produced in humans primarily by the parafollicular cells of the thyroid gland. It checks excess Ca2+ and phosphate in plasma by • decreasing mobilization from bones.

Question 5.
Name the hormone that helps in cell-mediated immunity.
Solution:
The hormone thymosin plays a maj or role in the development and differentiation of T-lymphocytes, which provide cell-mediated immunity.

Question 6.
A patient complains of constant thirst, excessive 3. passing of urine and low blood pressure. When the doctor checked the patients’ blood glucose and blood insulin level, the level were normal or 4. slightly low. The doctor diagnosed the condition a diabetes insipid us. But he decided to measure one more hormone in patients blood. Which hormones does the doctor intend to measure?
Solution:
The doctor intends to measure the hyperglycaemia hormone, and its action is opposite to that of insulin Excess of glucose in blood suppresses the secretion of glucose, whereas fall in glucose level enhance glucose production.

Question 7.
Correct the following statements by replacing the term underlined.
(a) Insulin is a steroid hormone.
(b) TSH is secreted from the corpus leteum.
(c) Tetraiodothyronine is an emergency hormone.
(d) the pineal gland is located on the anterior part of the kidney.
Solution:
(a) Insulin is a peptide hormone
(b) TSH is secreted from the pars distalis region ofpitutary.
(c) Adrenaline is an emergency hormone.
(d) The adrenal gland is located on the anterior part of the kidney.

Question 8.
Match the following columns.
Column I                           Column II
A. Oxytocin                     1. Amino acid derivative
B. Epinephrine                2. Steroid
C. Progesterone             3. Protein
D. Growth hormone       4. Peptide
Solution:
The correct matching is
Column I                             Column II
A. Oxytocin                 –       Peptide
B. Epinephrine            –       Amino acid derivative
C. Progesterone         –        Steroid
D. Growth hormone   –       Protein

SHORT ANSWER QUESTIONS

Question 1.
What is the role-played by luteinising hormones in males and females respectively.
Solution:

  1. LH and FSH stimulate activity of gonads and hence are called gonadotropins.
  2. Luteinising hormone (LH) in males stimulates the synthesis and secretion of hormones called androgens from testis. Androgens along with FSH (Follicle Stimulating Hormone) regulate spermatogenesis.
  3. LH induces ovulation of fully mature follicles in females and maintains the corpus luteum, formed from the remnants of the graafian follicles after ovulation. This secretes progesterone.

Question 2.
George comes on a vacation to India from US. The long journey disturbs his biological system and he suffers from jet lag. What is the cause of his discomfort?
Solution:

  1. The melatonin hormone secreted by the pineal gland is also called as ‘sleep hormone’ as it promotes sleep-wake cycle.
  2. The disruption of the body clock as it is out of synchronisation because of the unfamiliar time zone of the destination causes Jet lag. The body experiences different patterns of light and dark conditions than it is normally used to, this disrupts the natural sleep-wake cycle.
  3. A hormone that plays a key role in body rhythms and causes jet lag is melatonin. Eyes perceive darkness after the sun sets and alert the hypothalamus to begin releasing melatonin, which promotes sleep. Conversely, when the eyes perceive sunlight, they induce the hypothalamus to with hold melatonin prodtiction.
  4. The hypothalamus however cannot readjust its schedule instantly and it may take several days, to overcome this problem.

Question 3.
Inflammatory responses can be controlled by a certain steroid. Name the steroid, its source and also its other important functions.
Solution:

  1. Glucocorticoids cortisol in particular, produce anti-inflammatory reactions and suppress the immune response.
  2. The middle zone, in adrenal cortex which is the widest of three zones called zona fasciculata is the source for glucocorticoids.
  3. The glucocorticoids as the name suggests affect carbohydrate metabolism and metabolism of proteins and fats.
  4. They stimulate gluconeogenesis, lipolysis and proteolysis. They also inhibit utilization of amino acid and cellular uptake. Cortisol is also called stress hormone as it copes with stress.

Question 4.
Old people have weak immune system. What could be the reasons?
Solution:

  1. A major role in the development of the immune system is played by thymus.
  2. The thymus gland is a lobular structure located on the dorsal side of the heart and the aorta. It is derived from the endoderm of the embryo. Thymus secretes a hormone named thymosin which stimulates the development of white blood cells (WBCs), involved in producing immunity.
  3. In old individuals, thymus is degenerated which results in decreased production of thymosin. The immune system as a result becomes weak, in old people.

LONG ANSWER QUESTIONS

Question 1.
Calcium plays a very important role in the formation of bones. Write on the role of endocrine glands and hormones responsible for maintaining calcium homeostasis.
Solution:
The hormones and endocrine glands that are responsible for maintaining calcium
homeostasis, are thyroid and parathyroid glands j and their associated hormones are calcitonin and Parathyroid Hormone (PTH).
(i) Parathyroid glands – These glands developed from the endoderm of the embryo. The cells of parathyroid glands are
of two types – chief cells and oxyphil cells. The chief cells of the parathyroid glands secrete parathyroid hormone (PTH).
This hormone (PTH) is involved in regulation of calcium and phosphate balance between the blood and other tissue. It mobilises the release of calcium into the blood from bones. PTH increases reabsorption of calcium by the body organs like intestine and kidneys.
(ii) Thyroid gland – It is the largest endocrine gland located anterior to the thyroid cartilage of the larynx in the neck.

This gland plays a major role in maintaining calcium homeostasis. It releases thyrocalcitonin hormone produced by the parafollicular cells, also called, ‘C’ cells. This hormone is secreted when the calcium level in blood gets high.

It is a 32 amino acid peptide hormone that lowers the calcium level by suppressing release of calcium ions from the bones. Calcitonin thus has an action opposite to that of the parathyroid hormone in calcium homeostasis.
NCERT Exemplar Solutions for Class 11 Biology Chapter 22 Chemical Coordination and Integration 1

Question 2.
Hypothalamus is a supper master endocrine gland. Elaborate.
Solution:
Hypothalamus is a minor but extremely important part of the diencephalon that is involved in the mediation of endocrine, autonomic and behavioural fiinction.

It consists of several groups of neuro secretory cells called nuclei which produce hormones. Hypothalamus provides anatomical connection between the nervous and endocrine system. It controls the release of major hormones by

hypophysis which include :
(i) Growth Hormone Releasing Hormone stimulates the anterior lobe of the pituitary gland to release growth hormone or somatostatin.
(ii) MSH Releasing Hormone stimulates the intermediate lobe of the pituitary gland to secrete Melanocyte Stimulating Hormone (MSH)
The hormones released from hypothalamus are involved in the processes like temperature regulation, control of water balance in body, sexual behaviour and reproduction, control of daily cycles in physiological state, behaviour and mediation’ of emotional response hypothalamus is thus called as super master endocrine gland of body.
(iii) Prolactin Releasing Hormone (PRH) stimulates the anterior lobe of the pituitary gland to secret prolactin.
(iv) Gonadotropin Releasing Hormone stimulates the anterior lobe of the pituitary gland to release gonadotropic hormones (FSHandlH).
(v) Thyrotropm Releasing Hormone (TRH) stimulates the anterior lobe of pituitary gland to release Thyroid Stimulating Hormone (TSH).
(vi) Adrenocorticotrophic releasing Hormone (ARH) stimulates the anterior lobe of pituitary gland to secrete Adrenocorticotropic Hormone (ACTH). ACTH stimulates the synthesis and secretion of steroid hormones called glucocorticoids by adrenal glands.
The hormones released from hypothalamus are involved in the processes like temperature regulation, control of water balance in body, sexual behaviour and reproduction, control of daily cycles in physiological state, behaviour and mediation of emotional responses. Hypothalamus is thus called as super master endocrine gland of body.

We hope the NCERT Exemplar Solutions for Class 11 Biology at Work Chapter 22 Chemical Coordination and Integration, help you. If you have any query regarding NCERT Exemplar Solutions for Class 11 Biology at Work Chapter 22 Chemical Coordination and Integration, drop a comment below and we will get back to you at the earliest.

NCERT Exemplar Solutions for Class 11 Biology Chapter 21 Neural control and co-ordination

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NCERT Exemplar Solutions for Class 11 Biology Chapter 21 Neural control and co-ordination

These Solutions are part of NCERT Exemplar Solutions for Class 11 Biology. Here we have given NCERT Exemplar Solutions for Class 11 Biology Chapter 21 Neural control and co-ordination.

VERY SHORT ANSWER QUESTIONS

Question 1.
Rearrange the following in the correct order of involvement in electrical impulse movement.
Solution:
The correct order of involvement in electrical impulse movement is as follows:
(i) Dendrites
(ii) Cell body
(iii) Axon
(iv) Axon terminal (vi) Synaptic knob
NCERT Exemplar Solutions for Class 11 Biology Chapter 21 Neural control and co-ordination 1.1

Question 2.
Which cells of the retina enable us to see coloured objects around us?
Solution:
Cone cells present in unable us to see the colours. There are three types of cones which possess their own characteristic photopigments that respond to red, green and blue light.

Question 3.
Arrange the following in the order of reception and transmission of sound wave from the ear drum. Cochlear nerve, external auditory canal, ear drum, stapes, incus, malleus, cochlea.
Solution:
The reception and transmission of sound waves occurs in following order – External Auditory canal —» Eardrum —» Malleus —> Incus —> Stapes —>• Cochlea —> Cochlear nerve

Question 4.
During resting potential, the axonal membrane is polarized, indicate the movement of H-ve and -ve ions leading to polarisation diagrammatically.
Solution:
NCERT Exemplar Solutions for Class 11 Biology Chapter 21 Neural control and co-ordination 4.1

Question 5.
Our reaction like aggressive behaviour, use of abusive words, restlessness etc. are regulated by brain, name the parts involved.
Solution:
Functions as aggressive behaviour, use or abusive words, restlessness, etc. The inner part of cerebral hemispheres and a group of associated deep structures called limbic lobe or limbic system along with hypothalamus are involved.

Question 6.
What do grey and white matter in the brain represent?
Solution:
A major component of CNS is Grey matter consisting of neutronal cell bodies, dendrite, unmyelinated axons, glial cells and capillaries. White matter is also a component of CNS and consists mostly of gilal cell and myelinated axons.

Question 7.
Where is the hunger centre located in human brain?
Solution:
Hypothalamus in human brain contains many centres which control urge for eating and drinking.

Question 8.
Complete the statement by choosing appropriate match among the following.
NCERT Exemplar Solutions for Class 11 Biology Chapter 21 Neural control and co-ordination 8.1

Solution:
A. -> (3), B. -> (4), C. -> (2), D. -> (1)
NCERT Exemplar Solutions for Class 11 Biology Chapter 21 Neural control and co-ordination 8.2

SHORT ANSWER QUESTIONS

Question 1.
The major parts of the human neural system is depicted below. Fill in the empty boxes with appropriate
words.
NCERT Exemplar Solutions for Class 11 Biology Chapter 21 Neural control and co-ordination s1.1

Solution:
The major parts of the human neural system is filled in the boxes with appropriate words
NCERT Exemplar Solutions for Class 11 Biology Chapter 21 Neural control and co-ordination s1.2

Question 2.
Neuron system and computers share certain common features. Comment in five lines.
Solution:
In various organs the sensory neurons is present to sense the environment and extend the message to the brain. So, it is equivalent to input device of computers.
Brain acts as the CPU, or Central Processing Unit. The information gathered by sensory neurons is processed by brain and it gives command to the concerned organ to act accordingly. This message is taken or conveyed by motor neurons which act as output devices.

Question 3.
What is the function described to Eustachian tube?
Solution:
The eustachian tube forms connection between the middle ear cavity with the pharynx. It helps in equalising the pressure on either sides of the ear drum. At the pharyngeal opening of the eustachian tube there is a valve which normally remains closed.
The valve opens during yawning, swallowing and during an abrupt change in altitude, when air enters or leaves the tympanic cavity to v equalise the pressure of air on the two sides of the tympanic membrane.

LONG ANSWER QUESTIONS

Question 1.
Explain the process of the transport and release of neurotransmitter with the help of a labelled diagram showing a complete neuron, axon terminal and synapse.
Solution:
The three main parts of a neuron include the
(i) Cell body
(ii) Axon
(iii) Dendrites
Stimulus or nerve impulse of any kind passes from one neuron to another via axon. This nerve impulse is wave of bioelectric/electrochemical disturbance that passes along the neuron during conduction of an excitation.
NCERT Exemplar Solutions for Class 11 Biology Chapter 21 Neural control and co-ordination l1.1

  • Within a synapse transport and release of a neuro transmiter occurs.
  • At a chemical synapse, the membranes of the pre- and post-synaptic neurons are separated by a fluid-filled space called synaptic cleft. Chemicals called neurotransmitters are involved in the transmission of impulses at these synapses.
  • The axon terminals contain vesicles filled with these neurotransmitters.
  • Upon arrival of an impulse (action potential) at the axon terminal, it stimulates the movement of the synaptic vesciles towards the membrane, where they fuse with the plasma membrane and release their neurotransmitters in the synaptic cleft.
  • The released neurotransmitters bind to their specific receptors, present on the post-synaptic membrane. This binding opens ion channels allowing the entry of ions, that can generate a new action potential in the
    NCERT Exemplar Solutions for Class 11 Biology Chapter 21 Neural control and co-ordination l1.2

Question 2.
Explain the structure of middle and internal ear with the help of diagram.
Solution:
Ears are a part of statoacoustic organ meant for balancing and hearing the external ear in most mammals is a heap of tissue also called pinna. It is a part of auditory system.

The human ear consists of three main parts external ear, middle, ear and internal ear.

Structure of Middle Ear

  • The middle ear consists of three bones or ossicles-the malleus (hammer), incus (anvil and stapes (stir-up).
  • These bones are attached to one another in a chain-like manner.
  • The malleus is attached to the tympanic membrane and the stapes is attached to the oval window (a membrane beneath the stapes) of cochlea.
  • These three ossicles increase the efficiency of transmission of sound waves to the inner ear.
  • The middle ear also opens into the eustachian tube, which connects with the pharynx and maintains the pressure between the middle ear and the outside atmosphere.

Structure of Internal Ear

  • Thd inner ear consists of a labyrinth of chambers filled with fluid within temporal bone of the skull. The labyrinth consists of two parts the bony and membranous labyrinth. The bony labyrinth is a series of channels.
  • Membranous labyrinth lies inside these channels which is surrounded by a fluid called perilymph. The membranous labyrinth is filled with a fluid called endolymph. The coiled portion of the labyrinth is called cochlea.
  • The cochlea has two large canal separated by a small cochlear duct (scala media). An upper vestibular canal (scala vestibuli) and a lower tympanic canal (scala tympani). The vestibular and tympanic canals contain perilymph and the cochlear duct is filled with endolymph.
  • The wall of membranous labyrinth comes in contact with the fenestra ovalis at the base of scale vestibuli while the fenestra rotunda.
    NCERT Exemplar Solutions for Class 11 Biology Chapter 21 Neural control and co-ordination l2.1

We hope the NCERT Exemplar Solutions for Class 11 Biology at Work Chapter 21 Neural control and co-ordination, help you. If you have any query regarding NCERT Exemplar Solutions for Class 11 Biology at Work Chapter 21 Neural control and co-ordination, drop a comment below and we will get back to you at the earliest.

NCERT Exemplar Solutions for Class 11 Biology Chapter 20 Locomotion and Movement

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NCERT Exemplar Solutions for Class 11 Biology Chapter 20 Locomotion and Movement

These Solutions are part of NCERT Exemplar Solutions for Class 11 Biology. Here we have given NCERT Exemplar Solutions for Class 11 Biology Chapter 20 Locomotion and Movement.

VERY SHORT ANSWER QUESTIONS

Question 1.
Name the cells/ tissues in human body which
(a) exhibit amoeboid movement
(b) exhibit ciliary movement
Solution:
(a) Macrophages and leucocytes in blood exhibit amoeboid movement. Cytoskeletal elements like microfilaments are also involved in amoeboid movement.
(b) Ciliary Movement occurs mostly in the internal organs, lined by the ciliated epithelium, e.g., cilia in trachea helps in removing dust particle and foreign substances inhaled along with atmospheric air.
Passage of ova through the female reproductive tract is also facilitated by the ciliary movement. This is due to the presence of ciliated epithelium in the Fallopian tube.

Question 2.
Locomotion requires a perfect coordinated activity of muscular …… systems.
Solution:
Locomotion requires a prefect coordinated activity of muscular, skeletal and neural systems.

Question 3.
Sarcolemma, sarcoplasm and sarcoplasmic reticulum refer to particular type of cell in our body. Which is this cell and to what parts of that cell do these names refer to?
Solution:
Muscle fibre is lined by the plasma membrane called sarcolemma. Muscle fibre is a syncitium because sarcoplasm (the cytoplasm) of muscle fibre contains number of nuclei and sarcoplasmic reticulum is the endoplasmic reticulum of the muscle fibre and is the store house of calcium ions.

Question 4.
Label the different components of actin filament in the diagram given below
NCERT Exemplar Solutions for Class 11 Biology Chapter 20 Locomotion and Movement 4.1v
Solution:
Each actin filament is made of two ‘F (filamentous) actins helically wound to each other and each ‘F’ actin is a polymer of monomeric ‘G’ (globular) actins.
The different components of action filament can be represented as
NCERT Exemplar Solutions for Class 11 Biology Chapter 20 Locomotion and Movement 4.2v

Question 5.
What is the difference between the matrix of bones and cartilage?
Solution:
Difference between the matrix of ones and cartilage
NCERT Exemplar Solutions for Class 11 Biology Chapter 20 Locomotion and Movement 5.1v

Question 6.
Which tissue is affected by mysthenia gravis? What is the underlying cause.
Solution:
Myasthenia gravis is autoimmune disorder of skeletal muscle, which affects neuromuscular junction, that leads to fatigue, weakening and paralysis of the skeletal muscle.

Question 7.
How do our bone joints function without grinding noise and pain?
Solution:
The presence of synovial fluid, between articulating surface of the two bones enclosed within synovial cavity of synovial joints to enables out joints to function without grinding noise and pain.

Question 8.
Give the location of a ball and socket joint in a human body.
Solution:
In human body Ball and socket joint are present between humerus and pectoral girdle. These joints allows free movement of bone in all direction. E.g., shoulder joints (humerus bone in socket of pectoral girdle) and

SHORT ANSWER QUESTIONS

Question 1.
With respect to rib cage, explain the following
(a) bicephalic ribs
(b) true ribs
(c) floating ribs
Solution:
There are 12 pairs of ribs. Each rib consist of a thin flat bone dorsally connected to the vertebral column and ventrally to the sternum.
(a) Bicephalic ribs each rib has two articulating surfaces on its dorsal end hence, are called as bicephatic ribs.
(b) The first seven pairs of ribs are true ribs. These ribs are dorsally attached to the thoracic vertebrae and ventrally connected to the sternum with the help of hyaline cartilage.
(c) The last two pair (11th and 12th) of ribs are not connected ventrally to the sternum therefore, called as floating ribs.
NCERT Exemplar Solutions for Class 11 Biology Chapter 20 Locomotion and Movement 1.1s

Question 2.
Exchange of calcium between bone and ^extracellular fluid takes place under the
influence of certain hormones
(a) What will happen if of Ca2+ is in extracellular fluid?
(b) What will happen if very less amount of Ca2+ is in the extracellular fluid?
Solution:
Parathyroid and thyroid glands, function under the feed back control of blood calcium
(a) More Ca2+ concentration in extracellular fluid is associated with hyperparathyroidism. It causes demineralisation, resulting in softening and bending of the bones. This condition leads to osteoprosis.
(b) Very less amount of Ca2+ in extracellular fluid is associated with hypoparathyroidism. This increases the excitability or nerves and muscles, causing cramps, sustained contraction of the muscles of larynx, face, hands and feet. This disorder called parathyroid tetany or hypercalcemic tetany.

Question 3.
Rahul exercises regularly by visiting a gymnasium. Of late he is gaining weight. What could be the reasons? Choose the correct answer and elaborate.
(a) Rahul has gained weight due to accumulation of fats in body
(b) Rahul has gained weight due to increased muscle and less of fat
(c) Rahul has gained weight because his muscle shape has improved
(d) Rahul has gained weight because he is accumulating water in the body
Solution:
(b) Rahul has gained weight because the shape of his muscle has changed. Regular exercise increases the body muscle. There is an enlargement of muscles due to increase in the amount of sarcoplasm and mitochondria and the strength he to developed led him to gain the mass and size of body muscle and reduction in fat content.

Question 4.
Radha was running on a treadmill at a great speed for 15 minutes continuously. She stopped the treadmill and abruptly came out. For the next few minutes, she was breathing heavily/fast. Answer the following questions.
(a) What happened to her muscles when she did strenuously exercised?
(b) How did her breathing rate change?
Solution:
(a) Her muscles got fatigues due to continuous exercise because of the accumulation of lactic acid within skeletal muscles. Pain is also often experienced in the fatigued muscles.
(b) Her breathing rate changes from normal to
high as during as her body muscles require thus oxygen for the ATP production, than the normal value, her breathing thus enhances, to take most oxygen from the atmosphere.

Question 5.
Write a few lines about gout.
Solution:
Gout is a disease caused due to improper purine metabolism. It causes accumulation of uric acid and its crystals in the joints. The level of uric acid and crystals of its salts get raised in blood causing their accumulation in the joint to which causes gouty arthritis. The excess of urates in blood can also lead to the formation stones in the kidneys.

Question 6.
What are the points for articulation of pelvic and pectoral girdles?
Solution:

  1. Each half of the pectoral girdle consist of a clavicle and a scapula.
  2. The dorsal flat, triangular body of scapula has a slightly elevated ridge called the spine that, projects flat expanded process called the acromion and the clavicle articulating with it.
  3. There a depression below the acromion is called the glenoid cavity which articulates with the head of the humerous to form the shoulder joint.
  4. Pelvic girdle consist of two coxal bones, each formed by the fusioin of three bones, ilium, ischium and pubis. It articulates with femur through a cavity called acetabulum forming thigh joint.

LONG ANSWER QUESTIONS

Question 1.
How does a muscle shorten during its contracting and return to its original form during relaxation?
Solution:
Muscles contract due to formation of cross-bridge between the actin and myosin filament
(i) An ATP molecule j oins the active site on the head of myosin myofilament. These heads contains an enzyme, myosin ATPase along with Ca2+ and Mg2+ ions that catalyses the break down of ATP.
NCERT Exemplar Solutions for Class 11 Biology Chapter 20 Locomotion and Movement 1.3l
(ii) The energy is transferred to myosin head which straightens to join an active site on actin myofilament, forming a across-
NCERT Exemplar Solutions for Class 11 Biology Chapter 20 Locomotion and Movement 1.1l
(iii) The energised cross-bridges move, causing the attached actin filaments to move towards the centre of A-band. The Z-line is also pulled inwards causing shortening of sarcomere, contraction. During contraction A-bands retain the length, while I-bands get reduced.
(iv) The myosin head releases ADP and Pi where relaxes to its low energy state. The head detaches from actin myofilaments when new ATP molecule joins it and cross-bridge are broken.
(v) In the next cycle, the free head cleaves the new ATP. The cycles of cross-bridge formation and breakage is repeated causing further sliding.
NCERT Exemplar Solutions for Class 11 Biology Chapter 20 Locomotion and Movement 1.2l
(vi) After contraction muscle relaxation occurs when the calcium ions are pumped back to the sarcoplasmic cistemae, thus, blocking the sites on actin myofilaments. The Z-line returns to original positions or relaxation.

We hope the NCERT Exemplar Solutions for Class 11 Biology at Work Chapter 20 Locomotion and Movement, help you. If you have any query regarding NCERT Exemplar Solutions for Class 11 Biology at Work Chapter 20 Locomotion and Movement, drop a comment below and we will get back to you at the earliest.

NCERT Exemplar Solutions for Class 11 Biology Chapter 19 Excretory Products and their Elimination

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NCERT Exemplar Solutions for Class 11 Biology Chapter 19 Excretory Products and their Elimination

These Solutions are part of NCERT Exemplar Solutions for Class 11 Biology. Here we have given NCERT Exemplar Solutions for Class 11 Biology Chapter 19 Excretory Products and their Elimination.

VERY SHORT ANSWER QUESTIONS

Question 1.
Where does the selective reabsorption of glomerular filtrate take place?
Solution:
The selective reabsorption of glomerular filtrate takes place in Proximal Convoluted Tubules (PCT) and Distal Convoluted Tubules (DCT).

Question 2.
What is the excretory product from kidneys of reptiles?
Solution:
The excretory product from the kidney of reptile is uric acid.

Question 3.
What is the composition of sweat produced by sweat glands?
Solution:
Sweat produced by sweat glands is a watery fluid that containing NaCl, small amounts of urea, lactic acid, etc. It’s primary function is to facilitate a cooling effect on the body surface and also to helps in removal of water.

Question 4.
Identify the glands that perform the excretory function in prawns.
Solution:
In prawns, the excretory organs are known as antennary glands or green glands. These glands are white pea sized structures and opaque enclosed in the coxa of each 2nd antenna. They mainly excrete ammonia.

Question 5.
What is the excretory structure in Amoeba?
Solution:
Conractile vacuole performs the function of excretion as well as osmoregulation in amoeba.

Question 6.
The following abbreviations are used in the context of excretory functions, what do they stand for?
(a) ANF
(b) ADH
(c) GFR
(d) DCT
Solution:
(a) ANF Stands for Atrial Natriuretic Factor
(b) ADH Stands for Antidiuretic Hormone
(c) GFR Stands for Glomerular Filtration Rate
(d) DCT Stands for Distal Convoluted Tubule

Question 7.
Differentiate glycosuria from ketonuria.
Solution:
Difference between glycosuria and ketonuria is as follows
NCERT Exemplar Solutions for Class 11 Biology Chapter 19 Excretory Products and their Elimination 1

Question 8.
Mention any two metabolic disorders, which can be diagnosed by analysis of urine.
Solution:
Metabolic disorders that can be diagnosed by analysis of urine are
(i) Hematuria- It is a disorder in which blood cells are present in the urine, which could be a sign of kidney stone or a tumor in urinary tract.
(ii) Albuminuria- It is a disorder in which albumin is present in urine and occurs in nephritis i.e., inflammaton of glomeruli. In this condition the size of filtering slits becomes enlarged.

Question 9.
What are the main processes of urine formation?
Solution:
Urine formation includes glomerular filtration (ultra Alteration), selective reabsorption and tubular secretion that occurs in different parts of the nephron.
Glomerular filteration is carried out by glomerulus and is involve the filteration of blood.
Selective reabsorption is the absorption of filtrate through renal tubules either activity or passively.
Tubular secretin involves secretion through tubular cells in urine in order to maintain ionic and acid-base balance of body fluids.

Question 10.
Fill in the blanks appropriately
Organ Excretory wastes
(a) Kidneys ………..
(b) Lungs ………..
(c) Liver ………..
(d) Skin ………..
Solution:
Organ                             Excretory wastes
(a) Kidneys     ——>     Urine
(b) Lungs        ——>    C02
(c) Liver           ——>    Urea
(d) Skin           ——->   Sweat

SHORT ANSWER QUESTIONS

Question 1.
Show the structure of a renal corpuscle with the help of a diagram.
Solution:
The structure of a renal corpuscle is shown below.
NCERT Exemplar Solutions for Class 11 Biology Chapter 19 Excretory Products and their Elimination 2

Question 2.
What is the role played by renin-angiotensin in the regulation of kidney frictions?
Solution:
On activation by fall in the glomerular blood pressure/flow renin is released from the Juxta-Glomerular Apparatus (JGA).

It converts angiotensinogen in blood to angiotensin I and further to angiotensin II. Angiotensin II, being a powerful vasoconstrictor, increases the glomerular blood pressure and thereby Glomerular Filteration Rate (GFR). Angiotensin II also activates the adrenal cortex to release aldosterone.

This Aldosterone causes reabsprption of Na+ and water from the distal parts of the tubule. Which leads to an increase in blood pressure and GFR. This complex mechanism is generally known as Renin Angiotensin Aldosterone System of RAAS.

Question 3.
The composition of glomerular filtrate and urine is not same. Comment.
Solution:
Glomerular filtrate contains all the content of the blood plasma except proteins. About 180 litres of glomerular filtrate like water, glucose, nutrients ions etc. occurs. As a result, now the composition of urine is quite different from that of the glomerular filtrate. Some ions are also added to this fluid by tubules i.e. tubular secretion to maintain ionic and acid base balance of body fluids. Thus the composition of glomerular filtrate andd urine is not same.

Question 4.
What is the procedure advised for the correction of extreme renal failure? Give a brief account of it.
Solution:
The ultimate method for the correction of acute/ extreme renal failure (kidney failure) is, Kidney transplantation it is to minimise chances of rejection by the immune system of the host, functional kidney is used as a transplant from a donor, preferably close relative modem clinical procedures have increased the success rate of such a complicated technique.

Question 5.
Explain, why a haemodialysing unit called artificial kidney?
Solution:

  1. Haemodialysis is a method that become a boon for thousands of uremic (accumulation of urea in blood) patients all over the world. Haemodialysing unit act as artificial kidney by removing urea from patients blood due to kidney failure.
  2. In this process blood is drained from artery and pumped into a dialysing unit after the addition of an anticoagulant named heparin.
  3. The unit contains a coiled cellophane tube which is surrounded by a dialysing fluid having the same composition as that of plasma except nitrogenous waste.
  4. The porous cellophane mfcmbrane of the tube allows the passage of molecules that is based on concentration gradient.
  5. Absence of nitrogenous water in dialysing fluid these substances freely move out thereby clearing the blood.
  6. In the end the cleared blood is pumped back to the body through a vein after the addition of anti¬heparin to it thereby completing the process.
    NCERT Exemplar Solutions for Class 11 Biology Chapter 19 Excretory Products and their Elimination 3

LONG ANSWER QUESTIONS

Question 1.
Explain the mechanism of formation of concentrated urine in mammals.
Solution:
Mammals have the ability to produce concentrated urine. The loop of Henle and vasa recta play important role in it which is discussed as follows:
(i) the proximity between the Henle’s loop and vasa recta as well as the counter current that is formed due to the fiow of filtrate in two limp’s of Henle’s loop in opposite direction and help in opposite direction and help in maintaining an increasing osmolality towards the inner medullary interstitium, i.e., from 300 mOsmoL-1 in the cortex to about 1200 mOsmol-1 in the inner medulla.
NCERT Exemplar Solutions for Class 11 Biology Chapter 19 Excretory Products and their Elimination 4
NCERT Exemplar Solutions for Class 11 Biology Chapter 19 Excretory Products and their Elimination 6
(ii) This gradient is caused mainly due to NaCl and urea ascending limb of Henle’s loop transports NaCl, that is exchanged with the descending limb of vasa recta.
(iii) Through the ascending portion of vasa recta. NaCl is returned to the interstitium.
(iv) Similarly, a small amount of urea enters the thin segment of the ascending limb of Henle’s loop, which is transported back to the intersitium by the collecting tubule.
(v) This special arrangement of Henle’s loop, and vasa recta, is called the counter current mechanism.
(vi) The rate of dissipation is reduced by the counter current exchange. This in turn, reduces the rate at which the current must pump Na+ to maintain any given gradient.
(vii) Presence of such interstitial garden helps in an easy passage of water from the collecting tubule thereby concentrating the filtrate (urine).
(viii) Human kidneys produces urine nearly four times concentrated than the initial filtrate formed.

Question 2.
Describe the structure of a human kidney with the help of a labelled diagram.
Solution:

  • Human kidney are reddish-brown, bean-shaped structures that is situated between the last thoracic and third lumbar vertebra, which is closer to the dorsal inner wall of the abdominal cavity.
  • Each kidney of an adult human measures 10-12 cm in length, 5-7 cm in width, 2-3 cm in thickness with an average weight of 120-170 gm
  • The kidney is covered by a fibrous connective tissue i.e., the renal capsula, that protects the kidney.
  • Internally, it consists of outer dark cortex and an inner light medulla, both containing nephron, nephron is the structural and functional units of kidney.
  • The median concave border of a kidney contains a notch called hilum, that functions as route entry and exit of blood vessels, nerves and ureter.
  • The renal cortex is granular in appearance that contains convoluted tubules that malpighian corpuscles. The renal medulla contains loop of henle, collecting ducts and tubules and ducts ofBertini.
  • Medulla is divided into conical masses, the medullary pyramids that further form papillae.
  • The papillae form calyces, which join to renal pelvis leading to ureter. Between the medullary pyramids, cortex extends into medulla and forms renal columns which are called as column of Bertini.
    NCERT Exemplar Solutions for Class 11 Biology Chapter 19 Excretory Products and their Elimination 5

We hope the NCERT Exemplar Solutions for Class 11 Biology at Work Chapter 19 Excretory Products and their Elimination, help you. If you have any query regarding NCERT Exemplar Solutions for Class 11 Biology at Work Chapter 19 Excretory Products and their Elimination, drop a comment below and we will get back to you at the earliest.