Control & Coordination
Short Answer Questions
Question 34: Label the parts (a), (b), (c) and (d) and show the direction of flow of electrical signals in the following figure.
- Sensory neuron
- Spinal cord
- Motor neuron
Question 35: Name the plant hormones responsible for the following
- Elongation of cells
- Growth of stem
- Promotion of cell division
- Falling of senescent leaves
Answer: Abscissic acid
Question 36: Label the endocrine glands in the given figure.
- Pineal gland
- Pituitary gland
- Thyroid gland
Question 37: In the given figures, (a), (b) and (c), which appears more accurate and why?
Answer: Figure (a) appears more accurate because it is showing positive geotropic movement in roots and negative geotropic movement in stem.
Question 38: Label the parts of a neuron in the given figure.
- Axon terminals
Question 39: Match the terms of Column (A) with those of Column (B)
|Column A||Column B|
Question 40: What is a tropic movement? Explain with an example.
Answer: Tropic Movement: The movements which are in a particular direction in relation to the stimulus are called tropic movements. Tropic movements happen as a result of growth of a plant part in a particular direction. For example; the shoot usually grows in the direction of sunlight. This is called positive phototropic movement.
Question 41: What will happen if intake of iodine in our diet is low?
Answer: Iodine is an important constituent of thyroxine. Thyroxine governs the rate of general metabolism in the body. Lack of iodine in the diet can hamper general metabolism; which can lead to many complications. Moreover, deficiency of iodine also leads to a condition which is known as goiter. This manifests in the form of a permanent swelling in the neck.
Question 42: What happens at the synapse between two neurons?
Answer: Transmission of nerve impulses between two neurons takes place at through the synapse. The axon terminal of a neuron releases specialized chemicals; called neurotransmitters. These chemicals travel through the synapse and reach the dendrites of the next neuron. The nerve impulses travel along with the neurotransmitters.
Question 43: Answer the following:
- Which hormone is responsible for the changes noticed in females at puberty?
- Dwarfism results due to deficiency of which hormone?
Answer: Growth hormone
- Blood sugar level rises due to deficiency of which hormone?
- Iodine is necessary for the synthesis of which hormone?
Question 44: Answer the following:
- Name the endocrine gland associated with brain?
Answer: Pineal Gland
- Which gland secretes digestive enzymes as well as hormones?
- Name the endocrine gland associated with kidneys?
Answer: Adrenal Gland
- Which endocrine gland is present in males but not in females?