Test: Control & Coordination - 1 - Class 10 MCQ

Plants do not have any nervous system, but if we touch a sensitive plant such as Mimosa pudica, the leaves of the plant close down. This is due to nastic movement. The response of the plant parts in response to an external stimulus, where the direction of response is not determined by the direction of the stimulus, is known as nastic movement. In sensitive plants like Mimosa pudica, this movement is achieved by changing cell shapes through altering the water content and turgor pressure within their cells, leading to the observed movement.

The cerebellum, located in the hindbrain, is responsible for maintaining posture and balance, and for the precision of voluntary movements.

Auxin is a plant hormone that promotes cell elongation on the side of the plant away from the light, causing the plant to bend towards the light (phototropism).

Thyroxin is a crucial hormone produced by the thyroid gland, and understanding its synthesis and function is important. Here are some key points:

• Iodine is essential for the production of thyroxin. Without it, the thyroid cannot synthesise this hormone.
• Thyroxin regulates metabolism of proteins, carbohydrates, and fats in the body, ensuring proper energy balance.
• Deficiency of iodine can lead to conditions such as goitre, which is characterised by a swollen neck.
• Iron is not necessary for the synthesis of thyroxin, making statement D incorrect.

In summary, while iodine is vital for thyroxin production, iron does not play a role in its synthesis.

The hormone that is deficient in diabetic patients is insulin.

Insulin plays a crucial role in:

• Regulating blood sugar levels.
• Facilitating the uptake of glucose by cells.
• Preventing high blood sugar, which can lead to serious health issues.

In diabetes, the body either does not produce enough insulin or cannot use it effectively, resulting in elevated blood sugar levels.