Control and Coordination Class 10 MCQs Questions with Answers
Question 1.
The electrical impulse travels in a neuron from:
(a) Dendrite Axon → Axonal end → Cell body
(b) Cell body → Dendrite → Axon → Axonal end
(c) Dendrite → Cell body → Axon → Axonal end
(d) Axonal end → Axon → Cell body Dendrite
Answer:
(c) Dendrite → Cell body → Axon → Axonal end
Explanation: The electrical impulse travels from the dendrite to the cell body, and then along the axon to its axonal end. At the end of the axon, the electrical impulse sets off the release of some chemicals. These chemicals cross the gap, or synapse, and start a similar electrical impulse in a dendrite of the next neuron.
Question 2.
In a synapse, a chemical signal is transmitted from:
(a) The dendritic end of one neuron to the axonal end of another neuron.
(b) Axon to cell body of the same neuron.
(c) Cell body to the axonal end of the same neuron.
(d) The axonal end of one neuron to the dendritic end of another neuron.
Answer:
(d) The axonal end of one neuron to the dendritic end of another neuron.
Explanation: The chemical signal is transmitted from axonal end of one neuron to the dendritic end of another nueron. This microscopic gap is called synapse.
Question 3.
In a neuron, the conversion of electrical signal to a chemical signal occurs at/in:
(a) Cell body
(b) Axonal end
(c) Dendritic end
(d) Axon
Answer:
Question 4.
Which is the correct sequence of the components of a reflex arc?
(a) Receptors Muscles → Sensory neuron → Motor neuron → Spinal cord
(b) Receptors → Motor neuron → Spinal cord Sensory neuron → Muscle
(c) Receptors → Spinal cord → Sensory neuron → Motor neuron → Muscle
(d) Receptors → Sensory neuron → Spinal cord → Motor neuron → Muscle
Answer:
(d) Receptors → Sensory neuron → Spinal cord → Motor neuron → Muscle
Explanation: A stimulus received by the receptors present on skin, is transmitted to the sensory neuron, which carries it to the central nervous system (the spinal cord and brain).
A motor neuron carries the message from the central nervous system to the effector which could be a muscle, a gland or both.
Related Theory
Nerve based pathway performed by an impulse from the receptor of stimulus to the effector organ is called the reflex arc. A reflex action is a nerve mediated automatic and spontaneous response to a certain stimulus without sonsulting the wilt of the individual coughing, sneezing, etc.
Question 5.
Which of the following statements are true?
(I) Sudden action in response to something in the environment is called a reflex action.
(II) Sensory neurons carry signals from the spinal cord to muscles.
(III) Motor neurons carry signals from receptors to the spinal cord.
(IV) The path through which signals are transmitted from a receptor to muscle or a gland is called reflex arc.
(a) (I) and (II)
(b) (I) and (III)
(c) (I) and (IV)
(d) (I) (II) and (III)
Answer:
(c) (I) and (IV)
Explanation: Reflex action is a sudden action in response to some stimuli in the environment. Reflex arc is the path through which signals are transmitted from a receptor to a muscle or a gland.
Question 6.
Which of the following statements are true about the brain?
(I) The main thinking part of bi in is the hindbrain.
(II) Centres of hearing, smell, memory, sight, etc. are located in the fore-brain.
(III) Involuntary actions like salivation, vomiting and blood pressure are controlled by the medulla in the hind brain.
(IV) Cerebellum does not control posture and balance of the body.
(a) (I) and (II)
(b) (I) (II) and (III)
(c) (II) and (III)
(d) (III) and (IV)
Answer:
Question 7.
The spinal cord originates from:
(a) Cerebrum
(b) Medulla
(c) Pons
(d) Cerebellum
Answer:
Question 8.
The movement of shoot towards light is:
(a) Geotropism
(b) Hydrotropism
(c) Chemotropism
(d) Phototropism
Question 9.
The main function of abscisic acid in plants is to:
(a) Increase the length of cells
(b) Promote cell division
(c) Inhibit growth
(d) Promote growth of stem
Answer:
(c) Inhibit growth
Explanation: Abscisic acid (ABA) is one example of a hormone which inhibits growth. Its effects include wilting of leaves.
Related Theory
Auxin is synthesized at the shoot tip, helps the cells to grow longer. When light is coming from one side of the plant, auxin diffuses towards the shady side of the shoot. This concentration of auxin stimulates the cells to grow longer on the side of the shoot which is away from light.
Gibberellin helps in the growth of the stem.
Cytokinin promotes cell division, and it is natural then that they are present in greater concentration in areas of rapid cell division, as in fruits and seeds.
Abscisic acid inhibits growth. Its effects include wilting of leaves. It is also responsible for falling of senescent leaves.
Question 10.
Iodine is necessary for the synthesis of which hormone?
(a) Adrenaline
(b) Thyroxin
(c) Auxin
(d) Insulin
Answer:
(b) Thyroxin
Explanation: Iodine is necessary for the thyroid gland to make the thyroxin hormone. Thyroxin regulates carbohydrate, protein and fat metabolism in the body so as to provide the best balance for growth. Iodine is essential for the synthesis of thyroxin. In case iodine is deficient in our diet, there is a possibility that we might suffer from goitre. One of the symptoms in this disease is a swollen neck.
Question 11.
Choose the incorrect statement about insulin:
(a) It is produced from pancreas.
(b) It regulates growth and development of the body.
(c) It regulates blood sugar levels.
(d) Insufficient secretion of insulin will cause diabetes.
Answer:
Question 12.
Select the mismatched pair:
(a) Adrenaline – Pituitary gland
(b) Testosterone – Testes
(c) Oestrogen – Ovary
(d) Thyroxin – Thyroid gland
Answer:
(a) Adrenaline – Pituitary gland
Explanation: Adrenaline is secreted by the adrenal gland, whereas growth hormone is secreted by the pituitary gland.
Question 13.
The growth of tendril in pea plants is due to:
(a) The effect of light.
(b) The effect of gravity.
(c) Rapid cell divisions in tendrillar cells that are away from the support.
(d) Rapid cell divisions in tendrillar cells in contact with the support.
Answer:
Question 14.
The growth of pollen tubes towards ovules is due to:
(a) Hydrotropism
(b) Chemotropism
(c) Geotropism
(d) Phototropism
Answer:
Question 15.
The movement of sunflower in accordance with the path of the sun is due to:
(a) Phototropism
(b) Geotropism
(c) Chemotropism
(d) Hydrotropism
Answer:
Question 16.
Involuntary actions in the body are controlled by:
(a) Medulla in the forebrain
(b) Medulla in the midbrain
(c) Medulla in the hindbrain
(d) Medulla in the spinal cord
Answer:
(c) Medulla in the hindbrain
Explanation: Medulla is a part of the hindbrain and controls involuntary action.
Question 17.
Which of the following is not an involuntary action?
(a) Vomiting
(b) Salivation
(c) Heartbeat
(d) Chewing
Answer:
(d) Chewing
Explanation: The actions that are not under our direct control are known as involuntary actions. Vomiting, salivation and heartbeat are examples of involuntary action. These involuntary actions are controlled by the medulla in the hindbrain.
Question 18.
A doctor advised a person to take an injection of insulin because:
(a) His blood pressure was low.
(b) His heart was beating slowly.
(c) He was suffering from goitre.
(d) His sugar level in blood was high.
Answer:
(d) His sugar level in blood was high.
Explanation: A person taking injections of insulin is suffering from diabetes. Insulin is a hormone which is produced by the pancreas. It helps in regulating blood sugar levels. If not secreted in proper amounts, the sugar level in the blood rises, causing many harmful effects.
Question 19.
The hormone which increases fertility in males is called:
(a) Oestrogen
(b) Testosterone
(c) Insulin
(d) Growth hormone
Answer:
(b) Testosterone
Explanation: Testosterone is the male sex hormone necessary for sperm production. In addition to regulating the formation of sperms, testosterone brings changes in appearance seen in boys, at the time of puberty.
Question 20.
Which of the following endocrine glands is unpaired?
(a) Adrenal
(b) Testes
(c) Pituitary
(d) Ovary
Answer:
Question 21.
The junction between two neurons is called:
(a) Cell junction
(b) Neuromuscular junction
(c) Neural joint
(d) Synapse
Answer:
(d) Synapse
Related Theory
- Synapse is the junction between two neurons.
- Cell junction is junction between neighboring cells.
- Neuromuscular junction allows delivery of impulses from neurons to other cells, like muscles cells/gland.
Question 22.
In humans, life processes are controlled and regulated by:
(a) Reproductive and endocrine systems.
(b) Respiratory and nervous systems.
(c) Endocrine and digestive systems.
(d) Nervous and endocrine systems.
Answer:
Question 23.
Select the row containing incorrect information:
| Endocrine Gland | The function of hormone secreted |
| (a) Thyroid | Regulates carbohydrate, protein and fat metabolism |
| (b) Pituitary | Regulates growth and development of the body |
| (c) Pancreas | Increasing blood sugar levels |
| (d) Adrenal | Increasing heart rate |
Answer:
(c) Endocrine Gland: Pancreas; Function of hormone – Increasing blood sugar levels
Question 24.
Look at the figure below and identify the structure labelled incorrectly:
Answer:
(d) D-Dendrite
Explanation: Part labelled D is capillary and not dendrite, as dendrites receive nerve impulses.
Question 25.
Given below are four statements regarding endocrine glands and hoimones. Select the correct statements:
(I) Hormones are secreted by the endocrine glands.
(II) Some endocrine glands secrete hormones in response to other hormones.
(III) Hormones are required in large quantities.
(IV) Many hormones are controlled by some form of a feedback mechanism.
(a) Both (I) and (II)
(b) Both (I) and (III)
(c) (I), (II), and (III)
(d) (I), (II), and (IV)
Answer:
(d) (I), (II), and (IV)
Explanation: Hormones are very potent substances, which means that very small amounts of a hormone may have profound effects on metabolic processes. Some endocrine glands secrete hormones in response to other hormones. The hormones that cause the secretion of other hormones are called tropic hormones. A hormone from gland A causes gland B to secrete its hormone. Many hormones are controlled by some form of a negative feedback mechanism, in this type of system, a gland is sensitive to the concentration of a substance that it regulates. A negative feedback system causes a reversal of increases and decreases in body conditions in order to maintain a state of stability.
Question 26.
Given below are four statements regarding the movement in plants.
Select the incorrect statements.
(I) Movement in plants happens at a point as the point of touch.
(II) The plants use electrical-chemical means to convey information from cell to cell.
(III) There are specialised tissues in plants for the conduction of information.
(IV) Plant cells change shape by changing the amount of water in them
(a) Both (I) and (III)
(b) Both (I) and (IV)
(c) Both (II) and (III)
(d) Both (II) and (IV)
Answer:
Question 27.
The junction between two nerves is known as:
(a) Synapse
(b) Axon
(c) Dendrite
(d) Capillary
Answer:
(a) Synapse
Explanation: The junction between two neurons is known as synapse. It is the site of transmission of nerve impulses between two nerve cells (neurons) or between a neuron and a gland or muscle cell (effector). A synaptic connection between a neuron and a muscle cell is called a neuromuscular junction.
Question 28.
The plant hormone that promotes dormancy m seeds and buds is:
(a) Auxin
(b) Gibberellin
(c) Cytokinin
(d) Abscisic acid
Answer:
(d) Abscisic acid
Explanation: Abscisic acid is one example of a hormone which inhibits growth. Its effects include wilting of leaves and promoting dormancy in seeds and buds.
Question 29.
The secretion of which hormone leads to physical changes in the body when you are 10-12 years of age?
(a) Oestrogen from testes and testosterone from ovary.
(b) Oestrogen from adrenal gland and testosterone from pituitary gland.
(c) Testosterone from testes and Oestrogen from ovary.
(d) Testosterone from thyroid gland and Oestrogen from pituitary gland.
Assertion Reasoning questions Class 10 Science Chapter 7
For the following questions, two statements are given: one labeled Assertion (A) and the other labeled Reason (R) Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:
(a) Both (A) and (R) are true and (R) is the correct explanation of the assertion.
(b) Both (A) and (R) are true, but (R) is not the correct explanation of the assertion.
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.
Question 30.
Assertion (A): A growing plant appears to bend towards the direction of light.
Reason (R): The plant hormone auxin diffuses towards the shady side of the shoot.
Answer:
(a) Both (A) and (R) are true and (R) is the correct explanation of the (A).
Question 31.
Assertion (A): Plants convey the acquired information from cell to cell.
Reason (R): Plants have specialized tissues for the conduction of information.
Select the correct answer to the above question from the codes (a), (b), (c) and (d) as given below:
Question 32.
Assertion (A): In animals, the brain is the main controlling center for responding to changes in their environment.
Reason (R): The thinking process of the brain is not fast enough in animals.
Answer: (d) (A) is false, but (R) is true.
Explanation: Reflex arcs have evolved in animals as the thinking process of the brain is not fast enough. Reflex action is any spontaneous, involuntary, and automatic response to a stimulus due to a change in our environment. For e.g. when a person touches a hot plate a sudden action leading to the withdrawal of hand occurs in a certain manner, this path of manner determines the reflex arc.
Reflex arcs have evolved in animals in order to take sudden and involuntary actions which are required in certain circumstances where emergency response is required to save the body from situations that may lead to danger.