Class 10 Biology



Control & Coordination

Exemplar Problems Short Answer Questions

Label the parts (a), (b), (c) and (d) and show the direction of flow of electrical signals in the following figure.

reflex arc

Answer:

  • Sensory neuron
  • Spinal cord
  • Motor neuron
  • Effector

Name the plant hormones responsible for the following

  • Elongation of cells
    Answer: Auxin
  • Growth of stem
    Answer: Giberellin
  • Promotion of cell division
    Answer: Cytokinin
  • Falling of senescent leaves
    Answer: Abscissic acid

Label the endocrine glands in the given figure.

endocrine system

Answer:

  • Pineal gland
  • Pituitary gland
  • Thyroid gland
  • Thymus

In the given figures, (a), (b) and (c), which appears more accurate and why?

geotropic movement

Answer: Figure (a) appears more accurate because it is showing positive geotropic movement in roots and negative geotropic movement in stem.

Match the terms of Column (A) with those of Column (B)

Answer:

Column A Column B
Olfactory receptors Nose
Thermo receptors Skin
Gustatoreceptors Tongue
Photoreceptors Eye


Label the parts of a neuron in the given figure.

neuron

Answer:

  • Dendrites
  • Cyton
  • Axon
  • Axon terminals

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.

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.

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.

Answer the following:

  • Which hormone is responsible for the changes noticed in females at puberty?
    Answer: Oestrogen
  • Dwarfism results due to deficiency of which hormone?
    Answer: Growth hormone
  • Blood sugar level rises due to deficiency of which hormone?
    Answer: Insulin
  • Iodine is necessary for the synthesis of which hormone?
    Answer: Thyroxine

Answer the following:

  • Name the endocrine gland associated with brain?
    Answer: Pineal Gland
  • Which gland secretes digestive enzymes as well as hormones?
    Answer: Pancreas
  • Name the endocrine gland associated with kidneys?
    Answer: Adrenal Gland
  • Which endocrine gland is present in males but not in females?
    Answer: Testis