Bihar Board Class 10 · Science · Matric exam 2027
Chapter 7: Control and Coordination — notes
The chapter’s 8 parts in the book’s order — the first idea of each and the points Medha Ma’am writes on the board — and the summary at the end. The full lesson and a check question for each part are in the app.
1. Why living things need control and coordination
Okay, so, you know that moving things feel alive to us.
- • Movement = response to change in environment
- • Movement is carefully controlled, not random
- • Control and coordination: recognise event, then correct response
2. Nervous tissue and the neuron
Okay, so — think about touching something hot.
- • Receptors: tips of nerve cells detecting info
- • Gustatory receptors = taste; Olfactory receptors = smell
- • Path: dendrite tip -> cell body -> axon -> synapse
- • Synapse: the gap between two neurons
- • At synapse: chemicals cross gap, start impulse in next neuron
3. Reflex actions and the reflex arc
Okay, so, think about pulling your hand back from a flame.
- • Reflex arc: direct link between input nerve and output nerve
- • Formed in the spinal cord
- • Example: pulling hand back from a flame
- • Information also travels on to the brain
4. The human brain: fore-brain, mid-brain, hind-brain
Okay, so the spinal cord isn't just for reflexes.
- • Brain + spinal cord = central nervous system
- • Fore-brain: thinking, sensory areas, motor areas, hunger centre
- • Medulla (hind-brain): controls blood pressure, salivation, vomiting
- • Cerebellum (hind-brain): posture, balance, precision of voluntary actions
5. Protection of nervous tissue and how muscles move
Okay, so the brain is very delicate.
- • Brain: protected by bony box + fluid-filled balloon
- • Spinal cord: protected by vertebral column (backbone)
- • Muscle movement: special proteins change shape and arrangement
- • Result: muscle cell becomes shorter
6. Coordination in plants: movement without nerves or muscles
Okay, so — plants have no nerves, and no muscles.
- • Sensitive plant: quick movement, no growth - touch response
- • Seed germination: movement by growth - root down, stem up
- • Plants move by changing water content in cells (swell/shrink)
7. Tropic movements and plant hormones
Okay, so let's talk about how plants move.
- • Tropism: directional growth movement
- • Phototropism: shoot towards light, root away from light
- • Geotropism: root down, shoot up (response to gravity)
- • Auxin: shoot tip hormone, more on shady side, makes cells grow longer
- • Gibberellins: stem growth; Cytokinins: cell division; Abscisic acid: inhibits growth
8. Hormones in animals and the feedback mechanism
Okay, so animals also use chemical signals, not just nerves.
- • Adrenaline (adrenal glands): faster heartbeat, more blood to muscles, faster breathing
- • Thyroxin (thyroid, needs iodine): regulates metabolism; deficiency -> goitre
- • Growth hormone (pituitary): regulates growth; deficiency -> dwarfism
- • Testosterone (male), Oestrogen (female): puberty changes
- • Insulin (pancreas): regulates blood sugar
- • Feedback mechanism: rising sugar -> more insulin; falling sugar -> less insulin
Summary
Okay, so let's take stock of everything we've covered. Living things need control and coordination, to sense changes around them and respond correctly. In animals, this is done through nervous tissue — neurons passing electrical impulses across synapses. We saw how urgent dangers get handled fast, through reflex arcs formed in the spinal cord. The brain does the slower, bigger work — thinking, involuntary actions, balance — and it's divided into the fore-brain, mid-brain and hind-brain, all protected by the skull and the vertebral column. And at the end of it, it's the muscle cells that actually carry out the movement, using special proteins. Then we moved to plants. No nerves, no muscles there. Some movements are quick, from a change in water content, like in the sensitive plant. Others are slow, through growth — tropic movements like phototropism and geotropism — controlled by hormones such as auxin, gibberellins, cytokinins and abscisic acid. And finally, animals too use chemical coordination, through hormones — adrenaline, thyroxin, growth hormone, testosterone, oestrogen, insulin — released by endocrine glands. A feedback mechanism keeps the right amount of each hormone flowing. So tell me, between a reflex and a thought-out action, which one do you think is faster?
AskMedha · Medha Ma’am — Bihar Board Class 10 Science, Chapter 7. Written from the textbook, checked twice.
Questions parents and students ask
- How do I get the "Control and Coordination" notes as a PDF?
- Press "Save as PDF" — the phone’s print sheet opens; choose "Save as PDF" there. The PDF holds the notes only.
- Where are these notes written from?
- From the chapter’s own textbook text, part by part, in the book’s own terms; a second, independent model then checked every part against the book. The full lesson, a check question for each part and the practice are in the AskMedha app.
The same preparation, with Medha Ma’am — on your phone
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