NCERT MCQ Solutions for Class 10 Science Chapter 6 Control and Coordination

The cerebrum is the largest part of the human brain and is responsible for voluntary actions such as thinking, decision-making, memory, reasoning and controlling all sensory and motor functions.

Reflex actions are rapid automatic responses to stimuli which are processed by the spinal cord to provide instant action without the delay of routing through the brain.

Nastic movement in plants like Mimosa pudica occurs in response to touch. It is independent of the direction of stimulus and caused by changes in cell turgor pressure.

Insulin is a protein hormone secreted by the pancreas in animals. It regulates glucose metabolism and is not involved in plant growth or development unlike auxin and gibberellin.

Adrenaline is a hormone secreted in response to stress or fear. It increases heartbeat and respiration rates preparing the body for a fight or flight response.

A neuron is the basic unit of the nervous system. It is specialized to conduct electrical impulses throughout the body facilitating communication between the brain and different body parts.

Auxins promote cell elongation in plant stems and roots. They also play a role in phototropism and gravitropism by regulating differential growth in response to stimuli.

The cerebellum coordinates voluntary movements and maintains posture and balance. It ensures smooth and precise motor activity by adjusting signals from the motor cortex.

Insulin is produced by beta cells of the pancreas. It lowers blood glucose levels by promoting its absorption by body cells and storage in the liver as glycogen.

Phototropism is the growth of plant parts toward or away from light. It is usually controlled by the hormone auxin which accumulates on the shaded side causing curvature.

Abscisic acid inhibits growth and promotes stomatal closure during water stress leading to wilting. It acts as a stress hormone and also regulates dormancy and seed development.

Medulla oblongata is part of the brainstem and controls involuntary actions such as heartbeat, breathing and digestion. It transmits signals between the brain and spinal cord.

Estrogen is a primary female sex hormone secreted by ovaries. It regulates the menstrual cycle, development of secondary sex characteristics and maturation of female reproductive organs.

Cytokinins promote cell division and differentiation especially in plant shoots. They work along with auxins and are found in areas with active growth like root and shoot tips.

Iodine is required by the thyroid gland for producing thyroxine. Its deficiency can lead to goitre and metabolic imbalances due to underproduction of thyroid hormones.

Olfactory receptors are located in the nasal cavity. They detect airborne chemicals and send signals to the brain allowing us to perceive different odors.

The pituitary gland controls the function of other endocrine glands by secreting hormones like growth hormone and TSH. It regulates growth, metabolism and reproduction.

The vertebral column or backbone encloses the spinal cord in a protective bony structure. It prevents injuries and supports the body’s central nervous system.

During stress or emergency the adrenal medulla secretes adrenaline to increase heart rate, respiration and alertness. This enables the body to respond quickly in fight or flight situations.

The cerebrum is the seat of intelligence. It manages memory, reasoning, emotions, voluntary movement and sensory perception making it the most advanced and largest brain region.