Structure And Functions Of Human Body Organ Systems Class 10th Science Tamilnadu Board Solution

Class 10th Science Tamilnadu Board Solution
Part-a
  1. Unipolar neurons are found in the ___________.A. Brain B. Spinal Cord C. Embryonic nervous…
  2. The sensory organs contain ____________.A. Unipolar neuron B. Bipolar neuron C. Multipolar…
  3. The part of brain which controls emotional reactions in our body is __________.A.…
  4. One of the following is a part of the brain stem. Pick it out.A. Forebrain and midbrain B.…
  5. Spinal nerves are _________________.A. sensory nerves B. motor nerves C. mixed nerves D.…
  6. An endocrine gland found in the neck is _________________.A. adrenal gland B. pituitary…
  7. An endocrine gland which is both exocrine and endocrine is the _____________.A. pancreas…
  8. Normal blood glucose level in 1dl of blood is ______________.A. 80-100 mg/dl B. 80-120…
  9. The “T” lymphocytes are differentiated to resist infection in the _______________A.…
  10. In Meiosis-I, the pairing of homologous chromosomes take place during ___________ stage.A.…
  11. The two systems of the human body which help in the control and co-ordination of metabolic…
  12. Neurotransmitters are released at the synapse by _________________.A. Tips of Dendrites B.…
  13. The endocrine gland related to the immune system is ___________ .A. Thyroid B. Thymus C.…
  14. The hormone administered by doctors to a pregnant woman to help in childbirth during the…
  15. The important event of meiosis is the crossing over. It occurs during ________ .A.…
  16. Reduction division is the process by which gametes are produced. The cells in which…
  17. In Amoeba, the cell division takes place _____A. Involving changes in the chromatin…
  18. Pick out the item which has sequential arrangement.A. zygotene -Leptotene -Pachytene…
  19. Polio is a viral disease and the affected child suffers from physical disability of limbs.…
  20. Blinking when a beam of light is suddenly focussed on the eyes and sudden withdrawal of…
  21. The following are the parts of a neuron: a) Axon b) Terminal branches c) Cyton d)…
  22. For minor surgeries in the body, doctors administer local anaesthesia to a part of the…
  23. Assertion (A): All spinal nerves are mixed nerves. Reason (R): Each spinal nerve has a…
Part-b
  1. Name the two systems which help in the control and co-ordination of metabolic activities.…
  2. Differentiate medullated neurons from non-medullated neurons. Where are they found in the…
  3. Name the part of the brain which regulates heart beat and respiration. Where is it located…
  4. What is corpora quadrigemina? Name the functions associated with it.…
  5. What are endocrine glands? Name the secretions of these glands. How do these secretions…
  6. Name the following endocrine glands: i) The master of the endocrine orchestra ii) The dual…
  7. Which hormone(s) is/are called i) Personality hormone ii) fight, flight and fright…
  8. Name the male and female sex hormones. List out their functions.
  9. In which sub-stages of meiosis-I do the following events occur? i) pairing of homologous…
  10. Copy the diagram and label any two parts in the group given: (cyton, axon, dendron,…
  11. The diagram is of the human brain. Shade the areas marked A and B in the parts of the…
  12. On the basis of the function performed, pick out the right statements. i) Pituitary gland…
  13. Correct the statements, if they are wrong. i) Alpha cells produce insulin and beta cells…
  14. Here are a few statements about the endocrine system in man. State whether each of them is…
  15. Copy and complete the following table:
  16. Copy the diagram and label the parts with the help of the clues given: i) It is otherwise…
  17. Copy and identify the types of neurons given below:
  18. Here are some statements about meiosis. State whether each of them is true or false: i) It…
  19. Match the following:
  20. A person was riding a two-wheeler without wearing a helmet. He met with an accident and…
  21. Match the following:
  22. Observe the following diagrams that depict the transmission of nerve impulses through two…
  23. Which gland is called the ‘dual gland’? Why?
  24. A 16-year-old boy was brought to a doctor with a complaint of non-masculine features (lack…
Part-c
  1. Describe the structure of a neuron with the help of a neat, labelled diagram.…
  2. List out the various parts of the human brain and write a note on their functions.…
  3. Name the endocrine glands and their location in the human body. Describe any two of them…
  4. Why is meiosis called reduction division? Describe the various stages with relevant…
  5. Use words from the given list to complete the following paragraph. (The words may be used…
  6. Match these parts with their functions:- medulla oblongata, cerebellum, forebrain,…
  7. Observe the diagram of the human brain and identify the areas mentioned: i) The area…

Part-a
Question 1.

Unipolar neurons are found in the ___________.
A. Brain

B. Spinal Cord

C. Embryonic nervous tissue

D. Adult nervous tissue


Answer:

All other except embryonic nervous tissue have bipolar and multipolar neurons. Only embryonic nervous tissue has unipolar neurons in which development of nervous system is under process.


Question 2.

The sensory organs contain ____________.
A. Unipolar neuron

B. Bipolar neuron

C. Multipolar neuron

D. Medullated neuron


Answer:

All sensory organs contain bipolar neurons in which they have one axon at one end and one dendrite at other end. They don’t have unipolar and multipolar neurons.

They have bipolar neurons because they are the suitable one for the conduction of impulses in sensory organs.



Question 3.

The part of brain which controls emotional reactions in our body is __________.
A. Cerebellum

B. Cerebrum

C. Thalamus

D. Hypothalamus


Answer:

Hypothalamus is the part of brain which controls emotional reactions. All other parts given in the options like Cerebellum controls voluntary movements, Cerebrum controls intelligence, memory, reasoning etc and thalamus controls conduction of sensory and motor signals. None of the given options except hypothalamus controls emotional reactions.


Question 4.

One of the following is a part of the brain stem. Pick it out.
A. Forebrain and midbrain

B. Midbrain and hindbrain

C. Forebrain and hindbrain

D. Forebrain and spinal cord


Answer:

Brain stem is an extension of brain to the spinal cord. This brain stem is extended from midbrain, pons and medulla which are parts of hind brain to the spinal cord.

Therefore Midbrain and Hindbrain are parts of brain stem.


It can be better understood by following picture.



Question 5.

Spinal nerves are _________________.
A. sensory nerves

B. motor nerves

C. mixed nerves

D. innervating the brain


Answer:

Mixed nerves are those which contain both sensory nerve fibers and motor nerve fibers. Spinal nerve contain both sensory neurons i.e. can receive information from central nervous system and can give response using motor nerve fibers.


Question 6.

An endocrine gland found in the neck is _________________.
A. adrenal gland

B. pituitary gland

C. thyroid gland

D. pancreas


Answer:

The location of all other endocrine glands i.e. adrenal gland, pituitary gland and pancreas are Abdomen, brain and abdomen respectively.

Thyroid gland out of the given options is the only gland present in the neck.


From following picture the locations of various glands can be seen:



Question 7.

An endocrine gland which is both exocrine and endocrine is the _____________.
A. pancreas

B. pituitary

C. thyroid

D. adrenal


Answer:

Pancreas secrete both hormone from endocrine part of pancreas i.e. islets of Langerhans and enzymes from exocrine part of pancreas i.e. acinar cells. All other glands secrete only hormones and thus exhibit only endocrine nature.

Therefore, pancreas is both exocrine and endocrine.


Question 8.

Normal blood glucose level in 1dl of blood is ______________.
A. 80-100 mg/dl

B. 80-120 mg/dl

C. 80-150 mg/dl

D. 70-120 mg/dl


Answer:

This value represents the normal blood glucose level in 1 dl of blood maintained by the insulin and glucagon hormones of pancreas.

All other options represent values which are somewhat low or high than the normal blood glucose level. 80-120 mg/dl represents the correct range of blood glucose level maintained by insulin and glucagon.


Question 9.

The “T” lymphocytes are differentiated to resist infection in the _______________
A. parathyroid gland

B. lymph gland

C. thymus gland

D. adrenal gland


Answer:

“T” lymphocytes for their differentiation require the thymosin hormone which is secreted only by the thymus gland.

Other mentioned glands do not secrete thymosin hormone. Therefore, differentiation of “T” lymphocytes takes place only in the thymus gland.


Question 10.

In Meiosis-I, the pairing of homologous chromosomes take place during ___________ stage.
A. leptotene

B. zygotene

C. pachytene

D. diplotene


Answer:

During Zygotene process of meiosis I homologous chromosomes exhibit pairing with each other. In other steps like Leptotene- condensation of chromosome take place, Pachytene- crossing over of homologous chromosomes take place and in diplotene- terminalization take place.

Therefore, correct option is Zygotene.


It can be better understood with the following picture:



Question 11.

The two systems of the human body which help in the control and co-ordination of metabolic activities are _________________.
A. digestive and circulatory

B. respiratory and circulatory

C. excretory and skeletal

D. nervous and endocrine


Answer:

Nervous and endocrine systems are the two systems which controls and coordinates the metabolic processes. Nervous system does so by electrochemical coordination and endocrine system done so by chemical coordination.

All other processes given help to carry out different essential life processes but do not help in control and coordination.


Question 12.

Neurotransmitters are released at the synapse by _________________.
A. Tips of Dendrites

B. Synaptic Knobs

C. Organelles of Cyton

D. Myelin sheath of Axon


Answer:

Synaptic knobs for the transmission of impulse from one neuron to the other secrete the neurotransmitter. While the other parts like dendrites receive the stimulus, organelles play their respective roles in cell body and myelin sheath prevents leakage of impulse.

So, correct option is Synaptic knobs.


Question 13.

The endocrine gland related to the immune system is ___________ .
A. Thyroid

B. Thymus

C. Adrenal

D. Pineal


Answer:

Since thymus gland regulates the differentiation of the T- lymphocytes which play role in adaptive immune system.

Therefore, thymus gland is the endocrine gland related to the immune system.


Question 14.

The hormone administered by doctors to a pregnant woman to help in childbirth during the time of natural delivery is ____________ .
A. Oestrogen

B. Progesterone

C. Insulin

D. Relaxin


Answer:

Relaxin is the hormone administered by doctors to a pregnant woman to help in childbirth during the time of natural delivery because relaxin hormone helps in the expulsion of the baby from the uterus and it does so by causing relaxation of the pelvic muscles as its name suggests.

Other hormones oestrogen and progesterone are for maintaining pregnancy and insulin is for maintaining for blood glucose level.


Therefore relaxin is the correct option.


Question 15.

The important event of meiosis is the crossing over. It occurs during ________ .
A. Leptotene

B. Pachytene

C. Diplotene

D. Zygotene


Answer:

During pachytene process of meiosis crossing over between homologous chromosomes takes place. In this they homologous chromosomes exchanges their segments.

In other steps like Leptotene- condensation of chromosome take place, Diplotene- - terminalization take place and in Zygotene- pairing of homologous chromosomes takes place.


Therefore, correct option is Pachytene.


It can be better understood with the following picture:



Question 16.

Reduction division is the process by which gametes are produced. The cells in which reduction division take place are ____________ .
A. germinal epithelial cells

B. the sensory epithelial cells

C. cuboidal epithelial cells

D. columnar epithelial cells


Answer:

Reduction division takes place in germinal epithelial cells because these are part of germ cells i.e. gametes. All other cells mentioned are type of somatic cells which do not require reduction.

Therefore correct option is germinal epithelial cells.


Question 17.

In Amoeba, the cell division takes place _____
A. Involving changes in the chromatin reticulum

B. Without involving changes in the chromatin reticulum

C. Leading to reduction in the number of chromosomes

D. Without dividing the nucleus


Answer:

It is because amoeba is a unicellular organism which divides by the process Amitosis. In this process there is nothing like chromosome synthesis and no changes in the chromosome takes place prior to the division as take place during mitotic and meiotic divisions.

Therefore, in amoeba cell division take place without involving change in chromatin reticulum.


Question 18.

Pick out the item which has sequential arrangement.
A. zygotene ->Leptotene ->Pachytene ->Diplotene ->Diakinesis

B. Diakinesis ->zygotene ->Leptotene ->Pachytene ->Diplotene

C. Leptotene ->zygotene ->Pachytene ->Diplotene ->Diakinesis


Answer:

This is the sequence which is followed during the prophase I step of Meiosis I. For the division firstly condensation of chromosomes take place, then pairing of homologous chromosomes take place, after that crossing over, then terminalisation take place and finally disappearance of nuclear membrane and nucleolus takes place.

Since, above mentioned steps are followed by sequence (iii).


Therefore, correct answer is (iii).


It can be better understood with the following picture:



Question 19.

Polio is a viral disease and the affected child suffers from physical disability of limbs.

Which system of the body is mostly affected due to this infection?
A. Nervous system

B. Digestive system

C. Respiratory system

D. Excretory system


Answer:

Nervous system is the system which controls and coordinates the various body activities and movement of limbs is one of them. The polio virus causes physical disability because upon infection it causes destruction of the motor neurons which help in movement. As, motor neurons get destructed there is physical disability.

All other systems do not get affected to that much high level as nervous system gets affected.


Therefore, correct option is Nervous system.


Question 20.

Blinking when a beam of light is suddenly focussed on the eyes and sudden withdrawal of hand upon touching a hot body are some of the examples of reflex actions. Which part of the central nervous system acts as the centre these actions?
A. Forebrain

B. Spinal cord

C. Hindbrain

D. Synapse


Answer:

Reflex action is a process in which immediately message is sent to brain and an immediate response is also given.

It can happen only when neurons can transmit signals to the brain and from the brain. Also, it is an involuntary action which does not involve thinking process in which time is consumed. So, brain is not the centre for reflex actions.


In spinal cord we have mixed neurons and therefore an immediate action can take place. So, this process can take place only there.


Therefore, spinal cord is the correct answer. All other options do not play any role in the reflex actions.


Following picture explains the same:



Question 21.

The following are the parts of a neuron:

a) Axon b) Terminal branches

c) Cyton d) Dendrites

The correct pathway of a nerve impulse through these parts is _____________.
A. badc

B. dcab

C. bdac

D. adbc


Answer:

Firstly the stimulus is received with the help of dendrites, after that they are transmitted to cyton, and then they travel through the axon and at the end reaches to the terminal branches from where they are transmitted to another neuron.

Therefore correct sequence is : ii) dcab. It is also shown in following picture:



Question 22.

For minor surgeries in the body, doctors administer local anaesthesia to a part of the body so that the pain will not be felt by the patient. At which part, do you think, the nerve impulse is being arrested due to the effect of anaesthesia?
A. at cyton

B. at axon

C. at synapse

D. in the middle of axon


Answer:

Because synapse is the site from where the transmission of the impulse takes place. When the impulse of transmission is arrested the signal does not reach the brain and we do not feel any pain and sensation. Therefore anesthesia acts on synapses.


Question 23.

Assertion (A): All spinal nerves are mixed nerves.

Reason (R): Each spinal nerve has a sensory root and a motor root.
A. Both ‘A’ and ‘R’ are true and ‘R’ explains ‘A’.

B. Both ‘A’ and ‘R’ are true but ‘R’ doesn’t explain ‘A’.

C. Only ‘A’ is true but ‘R’ is false.

D. ‘A’ is false but ‘R’ is true.


Answer:

Mixed nerves are those nerves which contain both the sensory and motor neurons. Spinal nerves are one of them which can receive stimuli through sensory neurons and show effector functions using motor neurons.

Since both ‘A’ and ‘R’ are true and ‘R’ explains ‘A’. Therefore correct option is (i).



Part-b
Question 1.

Name the two systems which help in the control and co-ordination of metabolic activities.

Write any one difference between them.


Answer:

Nervous system and Endocrine systems help in control and coordination of metabolic activities.



Question 2.

Differentiate medullated neurons from non-medullated neurons. Where are they found in the nervous system?


Answer:


● Medullated neurons are present in the neurons of central nervous systems and a somatic nervous system where neurons are of larger length, present in the white matter of the brain.


● Nonmedullated neurons are present in the neurons of an autonomic nervous system where neurons are of smaller length, present in the grey matter of the brain.


● In general, neurons which are long are medullated and which are short are non- medullated.