Control and Coordination Class 10 Worksheet Science Chapter 6

Multiple Choice Questions

Q1: Grey matter is
(a) a fluid
(b) cluster of cytons
(c) a hormone
(d) a network of blood vessel
Ans: (b)
Grey matter is a cluster of cytons. The grey matter found in the brain and spinal cord is primarily made up of neuron cell bodies (cytons). These neuron bodies are responsible for processing and transmitting information in the nervous system, thereby playing a crucial role in sensory perception, muscle control, and decision-making.

Q2: Which of the following is a plant hormone?
(a) Insulin
(b) Thyroxin
(c) Oestrogen
(d) Cytokinin
Ans: (d)

Cytokinin is a plant hormone. Plant hormones, also known as phytohormones, play a crucial role in plant growth and development. Cytokinins are one such group of plant hormones that promote cell division in plant roots and shoots.

Q3: Secondary sexual characters are influenced by
(a) thyroxine
(b) adrenaline
(c) testosterone
(d) oestrogen
Ans: (C , D)

Secondary sexual characters are influenced by testosterone and oestrogen. These are sex hormones that play a crucial role in the development of secondary sexual characteristics in males and females respectively. Testosterone leads to the development of features like facial hair, deepening of voice in males while oestrogen is responsible for the development of breasts and widening of hips in females.

Q4: The brain is responsible for:
(a) thinking.
(b) regulating the heart beat.
(c) balancing the body.
(d) all of the above.  
Ans: (d)
The brain is responsible for thinking, regulating the heartbeat, and balancing the body. It is the control center of our body and is responsible for controlling and coordinating all the activities in the body including voluntary activities like thinking, and involuntary activities like regulating heartbeat and maintaining body balance.

Q5: Plant growth is/are promoted by
(a) cytokinin
(b) auxin
(c) gibberellin
(d) abscisic acid
Ans: (A , B ,C)
Plant growth is promoted by cytokinin, auxin, and gibberellin. These are all types of plant hormones that play a crucial role in plant growth and development. Cytokinins promote cell division, auxins stimulate cell elongation and gibber

Q6: Which part of the brain is concerned with muscular coordination in the body?
(a) Temporal toke
(b) Cerebellum
(c) Pons
(d) Parietal 10 be
Ans: (b)
It is responsible for precision of voluntary actions and maintaining the posture and balance of the body.

Q7: Which centre regulates swallowing, coughing and vomiting?
(a) Pons
(b) cerebrum
(c) spinal cord
(d) medulla oblongata
Ans: (d)
The medulla oblongata is located in the brain stem, anterior to cerebellum. This is a cone-shaped nerve cell located in the hind brain, which controls a number of involuntary functions like coughing, sneezing and vomitting.

Q8: Which one of the endocrine glands is known as master gland?
(a) Adrenal
(b) Pituitary gland
(c) Thyroid
(d) Parathyroid
Ans: (b)
Pituitary gland is known as master gland as it controls the release of other hormones that are required for growth and development.

Q9: Which is the longest part of the neuron?
(a) Dendrites
(b) myelin sheath
(c) cell body
(d) Axon
Ans: (d)
Axon is the longest part of neuron that connects cell body and nerve ending. Axons are in effect the primary transmission lines of the nervous system.  

Q10: The hormone responsible for anger is
(a) adrenaline
(b) growth hormone
(c) oestrogen
(d) insulin
Ans: (a)
The adrenal glands flood the body with stress hormones, such as adrenaline and cortisol.

Fill in the blanks
Q11: The cells of the islets of Langerhans produce ____________.
Ans: insulin
The cells of the islets of Langerhans, which are located in the pancreas, are responsible for the production of insulin. Insulin is a hormone that regulates the amount of glucose in the blood. It allows cells in the body to take in sugar from the bloodstream and use it for energy.

Q12: The thymus gland is ____________ in children.
Ans: present
The thymus gland is an organ that is present in children. As a part of the immune system, it plays a crucial role in the development and function of the body's immune defenses. In children, the thymus gland is active in producing T-cells, which help fight off infections and diseases. As we get older, the thymus gland gradually shrinks and becomes less active.

Q13: _________ and __________ protect the brain of mammals.
Ans: Cranium, meninges
The brain of mammals is protected by the cranium and meninges. The cranium is the bony structure that forms the skull, providing a hard casing to protect the brain. The meninges are three layers of protective tissue that surround the brain and spinal cord, providing further protection and support.

Q14: __________ is plant’s response to contact with hard surface.
Ans: Thigmotropism
Thigmotropism is a plant's response to contact with a hard surface. This phenomenon is commonly observed in climbing plants, where the plant's growth direction changes when it comes into contact with a solid object. This response allows plants to navigate their environment and find support structures to help them grow.

Mark the statements true(T) or false(F)
Q15: Sensory nerve connects the dorsal root of the spinal cord.
Ans: True. The sensory nerve does indeed connect to the dorsal root of the spinal cord. The dorsal root carries sensory information from the body to the spinal cord, which is then transmitted to the brain.

Q16: Testosterone produces femaleness.
Ans: False. Testosterone does not produce femaleness. It is a male sex hormone that is responsible for developing and maintaining male sex characteristics. The hormone that produces femaleness is estrogen.

Q17: Parathormone is produced by adrenal gland.
Ans: False. Parathormone is not produced by the adrenal gland. It is actually produced by the parathyroid glands, which are located in the neck near the thyroid gland. Parathormone plays a key role in regulating the body's calcium and phosphate levels.

Very Short Question Answers

Q19: Name the hormone which controls (i.e. reduces) the level of sugar in blood, and the gland which secretes it.
Ans: Insulin, controls (i.e. reduces) the level of sugar in blood, and Pancreas is the gland which secretes it. 

Q20: Name the structure that is responsible for reflex action.
Ans: Spinal cord is responsible for reflex action.  

Q21:  Why are roots called positively geotropic?
Ans: This is because the roots always grow towards the gravity of the Earth.

Q22: Specify the location of the olfactory lobe.
Ans: Cerebrum

Q23: Name the hormone produced by the ovaries.
Ans: Oestrogen

Q24: Name the part of the brain which controls involuntary action.
Ans: Medulla oblongata

Q25: Name the hormone which contains iodine.
Ans: Thyroxine

Q26: Name the cells that produce insulin.
Ans: A cluster of cells called islets of Langerhans

Q27: Mention the number of cranial nerves.
Ans: 12

Q30: Specify the location of the pituitary gland.
Ans: Attached to the diencephalon in cerebrum

Q31: Name the part of the brain which controls intelligence.
Ans: Cerebrum

Q32: Name the phytohormone that inhibits growth.
Ans: Abscisic acid

Q33: Differentiate between Spinal reflex and Cranial reflex
Ans: 

• Spinal reflex                             
  • It occurs through the spinal nerves.       
  • It is controlled by the spinal cord.
• Cranial reflex
  • It occurs through the cranial nerves.
  • It is controlled by the brain.

Q34: What do you understand by the sleep movement of plant organs? 
Ans: Sleep movement or Nyctinasty is the circadian rhythmic nastic movement of higher plants in response to the onset of darkness. Examples are the closing of the petals of a flower at dusk and the sleep movements of the leaves of many legumes.

Q35: Describe cavities of brain.
Ans:

• The brain is somewhat a hollow structure containing many cavities of various sizes.
• These cavities are known as ventricles.
• Each cerebral hemisphere contains a cavity, the first and second ventricles. These ventricles are connected with the third ventricle by a canal.
• The third ventricle is present in the thalamus. It is connected with the fourth ventricle by a small central canal present in the mid brain. The roof of the third ventricle also contains clusters of blood vessels which secrete cerebrospinal fluid.
• The medulla contains the fourth ventricle. This ventricle is formed by the enlargement of the central canal of the spinal cord. The roof of the fourth ventricle also contains tufts of blood vessels which secrete part of the cerebrospinal fluid. 

Q36: Which part of the brain is more important? Why? 
Ans: The medulla oblongata is the most important part of the brain. Because the medulla oblongata helps regulate breathing, heart and blood vessel function, digestion, sneezing, and swallowing. This part of the brain is a center for respiration and circulation.

Long Question Answers

Q37: How are involuntary actions and reflex actions different from each other?
Ans: Involuntary action is the set of muscle movement which do not require thinking. But it is controlled by brain for example heart beat. While on the other hand, the reflex action is rapid and spontaneous action in response to any stimulus. For example closing of eyes immediately, when bright light is focused.

Q38: Explain briefly movements in plants.
Ans: Plant Movement

Tropic movement or tropism

• Directional movement of specific part of plant in response to external stimuli is called tropism.
• These movements are very slow.The movement of plant part can be either towards or away from stimulus.
• If the movement of plant is towards stimulus,it is called positive stimulus.
• If the movement of plant is away from stimulus,it is called negative stimulus.

(i) Phototropism: It is the directional movement of plant part in response to light stimulus.
If plant part move towards light it is called as positive phototropism.

• For Example: Stem or shoot
  If plant part move away from light it is called as negative phototropism.
• For Example: Roots

(ii) Geotropism: It is the response to gravity.

If the plant part moves in the direction of gravity it is called positive geotropism

• For Example: Roots grow downwards.

If the plant part moves against the direction of gravity it is called negative geotropism.

• For Example: Stem grows upwards

(iii) Chemotropism: Response to chemical stimuli.

• If Plant part move towards chemical stimuli it is positive chemotropism
• If plant part move away from chemical stimuli it is negative chemotropism.

(iv) Hydrotropism : Response to water. 

Q39: Describe the central nervous system in human beings. 
Ans: The central nervous system in human beings consists of brain and spinal cord.

• Brain: Brain is the highest coordinating centre in the body. It is covered by meninges, which is made up of three layers. It is protected by cranium. Brain is broadly divided into three parts, forebrain, midbrain and hindbrain a. Forebrain: The forebrain includes cerebrum and olfactory lobes. Cerebrum is the largest part of the brain. It consists of two cerebral hemispheres. Sensory and motor receptors are present in the brain. There are various regions for reception of vision (occipital lobe), reception of sound (temporal lobe), touch, smell, temperature (parietal lobe) and muscular activities (frontal lobe).
  Olfactory lobes are one in pair and receives olfactory nerves.
  • Midbrain: It is the small portion of the brain that connects cerebrum with the other parts of the brain and spinal cord.
  • Hindbrain: It consists of cerebellum, pons and medulla oblongata.
  • Cerebellum is responsible for coordination and adjustment of movement and posture. Pons regulate respiration. Medulla oblongata regulates swallowing, coughing, sneezing and vomiting.
• Spinal cord: Medulla oblongata extends downwards, enclosed in vertebral column to form a cylindrical structure known as spinal cord. It is also covered by meninges. It is the reflex centre of the body.

Q40: What is the need for a system of control and coordination in an organism?
Ans: There are various organs in an organism. These organs must be carefully controlled and coordinated for the survival of an organism. All daily decisions that include voluntary and involuntary actions are controlled by central nervous system (CNS).

Q41: Which signals will get disrupted in case of a spinal cord injury?
Ans: In case of the spinal cord injury, the signals coming from the nerves as well as the signals coming to the receptors will be disrupted.

Q42: How does chemical coordination occur in plants?
Ans: Chemical coordination occurs in plants with the help of plant hormones. Different plant hormones help to coordinate growth, development, and responses to the environment. For example, auxin promotes cell growth, gibberellins promote stem growth, cytokinins promote cell division and abscisic acid inhibits growth and its effects include wilting of leaves.

Q43: What is the function of receptors in our body? Think of situations where receptors do not work properly. What problems are likely to arise?
Ans: Functions of receptors:

• They sense the external stimuli such as heat or pain.
• They also trigger an impulse in the sensory neuron which sends message to the spinal cord.

When the receptors are damaged, the external stimuli transferring signals to the brain are not felt. For example, in the case of damaged receptors, if we accidentally touch any hot object, then our hands might get burnt as damaged receptors cannot perceive the external stimuli of heat and pain.

Q44: How does phototropism occur in plants?
Ans: The growth movement in plants in response to light stimulus due to auxin plant hormone is known as phototropism. The shoots show positive phototropism and the roots show negative phototropism. This means that the shoots bend towards the source of light whereas the roots bend away from the light source.