Is it correct to say: Confusing reflex action with voluntary action?

Reflex is automatic, spinal-cord mediated. Voluntary involves conscious brain (moving hand deliberately).

Is it correct to say: Saying pituitary secretes only growth hormone?

Pituitary is 'master gland' — secretes GH, TSH, FSH, LH, ADH, oxytocin and prolactin among others.

Is it correct to say: Placing sensory neurons in the motor pathway?

Sensory neuron: receptor → CNS. Motor neuron: CNS → effector. Direction matters.

Is it correct to say: Assuming plants have a nervous system?

Plants respond to stimuli using hormones (chemical signals) — no nerves. Growth movements are tropisms.

Is it correct to say: Confusing endocrine and exocrine glands?

Endocrine: ductless, release hormones into blood. Exocrine: have ducts, release into cavities (sweat, sebum, saliva).

Is it correct to say: Insulin and glucagon both raise blood sugar?

Insulin LOWERS blood sugar (from pancreas β-cells). Glucagon RAISES it (from α-cells).

Control and Coordination

Nervous system, reflex arc, endocrine glands and plant hormones — Maharashtra SSC Science Part 2

📐 5 formulas✏️ 3 examples🎯 6 practice⚖️ 5 marks🏫 Maharashtra State Board📚 Class 10✓ 2025–26 syllabus

💡

Board Exam Tips

→Diagram of neuron with parts labelled — 3-mark question every SSC.
→Reflex arc with a real-life example (touching hot object) — repeat 3-mark.
→Endocrine glands + their hormones + function table — 4-mark HOTS.
→Plant hormones (auxin, gibberellin, cytokinin, ABA, ethylene) and one function each — 2 marks.
→Distinguish nervous vs hormonal control — SSC comparison ask.

📊 Diagram

Neuron with dendrites, cell body, axon and synapse labelled

📐 Formulas(5)

Reflex Arc Sequence★ Board fav

Stimulus \to Receptor \to Sensory neuron \to Spinal cord \to Motor neuron \to Effector \to Response

Nerve Impulse Speed

v \approx 100 m/s (myelinated)

Neurotransmitter Release at Synapse

Impulse \to C a^{2 +} influx \to Vesicles fuse \to Neurotransmitter release

Auxin Effect on Plants★ Board fav

Auxin \to Cell elongation \to Phototropism

Feedback Regulation of Hormones

Level high \to Gland stops secretion; Level low \to Gland secretes

✏️ Solved Examples

1Solved Exampleeasy4 steps

State any three differences between the nervous and hormonal systems of control.

Signal type

Nervous: electrical; Hormonal: chemical

2Solved Exampleboard4 steps

Explain reflex arc with a labelled diagram. Give one example.

Definition — an automatic response to a stimulus not involving conscious brain

Reflex action

3Solved ExampleHOTS5 steps

A patient has excessive urination and constant thirst. Which hormone deficiency is likely and from which gland? Suggest treatment.

Symptoms — polyuria (excess urine) and polydipsia (excess thirst)

Polyuria + polydipsia

⚠️ Traps & Common Mistakes

⚠️Common Mistakes6

1
Confusing reflex action with voluntary action
✓Reflex is automatic, spinal-cord mediated. Voluntary involves conscious brain (moving hand deliberately).
2
Saying pituitary secretes only growth hormone
✓Pituitary is 'master gland' — secretes GH, TSH, FSH, LH, ADH, oxytocin and prolactin among others.
3
Placing sensory neurons in the motor pathway
✓Sensory neuron: receptor → CNS. Motor neuron: CNS → effector. Direction matters.
4
Assuming plants have a nervous system
✓Plants respond to stimuli using hormones (chemical signals) — no nerves. Growth movements are tropisms.
5
Confusing endocrine and exocrine glands
✓Endocrine: ductless, release hormones into blood. Exocrine: have ducts, release into cavities (sweat, sebum, saliva).
6
Insulin and glucagon both raise blood sugar
✓Insulin LOWERS blood sugar (from pancreas β-cells). Glucagon RAISES it (from α-cells).

🎯 Practice Yourself

🎯Practice Yourself6 questions

Q1
State the function of cerebrum and cerebellum.
Q2
Name the hormones secreted by the thyroid gland and their function.
Q3
Give two examples of plant tropisms.
Q4
State one function each of insulin and adrenaline.
Q5
Which structure connects two neurons?
Q6
Name the hormone that helps in ripening of fruits.

📝 Notes

Control and Coordination — Maharashtra SSC

Chapter 3 of Science Part 2. Living organisms coordinate their internal environment and responses to external stimuli through two systems: nervous (fast) and hormonal (slow but sustained).

Nervous system architecture

Central nervous system (CNS): brain + spinal cord.
Peripheral nervous system (PNS): cranial nerves + spinal nerves.
Autonomic nervous system: sympathetic (fight/flight) + parasympathetic (rest/digest).

The neuron — the basic unit

Dendrites: receive signals.
Cell body (soma): processes information.
Axon: transmits impulse.
Myelin sheath: insulates axon, speeds transmission.
Synapse: gap where neurotransmitter is released to the next neuron.

Reflex arc — the fast reaction

Stimulus → receptor → sensory neuron → spinal cord (relay neuron) → motor neuron → effector → response.

Purpose: instant, life-saving reaction without waiting for brain processing.

Endocrine glands — SSC-favourite table

| Gland | Hormone | Function | |---|---|---| | Pituitary | GH, TSH, FSH, LH | Master gland; growth, other glands | | Thyroid | Thyroxine | Metabolism | | Parathyroid | PTH | Calcium homeostasis | | Adrenal | Adrenaline, cortisol | Fight or flight, stress | | Pancreas | Insulin, glucagon | Blood sugar | | Ovary | Estrogen, progesterone | Female sex characters | | Testis | Testosterone | Male sex characters |

Plant hormones — five to remember

| Hormone | Function | |---|---| | Auxin | Cell elongation, phototropism | | Gibberellin | Stem elongation, seed germination | | Cytokinin | Cell division, delay ageing | | Abscisic acid (ABA) | Stress response, seed dormancy | | Ethylene | Fruit ripening |

Tropisms — plant movements

Phototropism: response to light.
Geotropism (gravitropism): response to gravity.
Hydrotropism: response to water.
Thigmotropism: response to touch (climbers).
Chemotropism: response to chemicals (pollen tube).

Board vs CBSE

Both boards teach identical material. Maharashtra SSC gives more marks to labelled diagrams (neuron, brain, endocrine chart) — practise clear diagrams.