R
Rishtaara
Science · Class 10

Control and Coordination

Nervous and hormonal coordination; reflex arc and endocrine glands.

4 sections15–25 min read6 MCQs · 2 examples

Chapter Overview

Organisms respond to stimuli via nervous and hormonal systems. Covers reflex arc, brain structure, plant hormones (tropisms), endocrine glands, and feedback regulation in humans.

Nervous System

  • Neuron: dendrite → cell body → axon → synapse
  • Reflex arc: receptor → sensory neuron → CNS → motor neuron → effector
  • Brain: cerebrum (thinking), cerebellum (balance), medulla (involuntary)

Plant Hormones

  • Auxin: cell elongation, phototropism
  • Gibberellins: stem growth
  • Cytokinins: cell division
  • Abscisic acid: wilting, dormancy

Endocrine System

  • Pituitary: master gland
  • Thyroid: thyroxine — metabolism
  • Adrenal: adrenaline — fight or flight
  • Pancreas: insulin and glucagon — blood sugar

Solved Examples

Step-by-step solutions — read each step before checking the final answer.

Reflex action

Touch hot object — explain reflex.

  1. 1Receptor in skin detects heat
  2. 2Impulse via sensory neuron to spinal cord
  3. 3Motor neuron → muscle contracts — hand withdraws
  4. 4Brain informed later

Answer

Spinal reflex — fast, involuntary

Diabetes link

Role of insulin?

  1. 1Pancreas secretes insulin
  2. 2Lowers blood glucose
  3. 3Deficiency → diabetes mellitus

Answer

Insulin regulates blood sugar

Key Points to Remember

  • Electrical impulse + chemical at synapse
  • Phototropism: growth towards light (auxin)
  • Adrenaline increases heart rate

Exam Tips

  • Draw reflex arc diagram
  • Tabulate plant hormones and functions
  • Know gland, hormone, function

Practice MCQs — Control and Coordination

Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.

Question 1 of 6Score: 0/0

Reflex arc centre is often: