Biology

CO ORDINATION

1. Hypothalamus controls pituitary gland.

2.Brain is covered by three layers called meninges.

3.Afferent neurons are also called sensory neurons and efferent neurons are motor nerves.

4.Cerebellum maintains posture, equilibrium and muscle tone.

5. Interruptions in Myelin sheath (made up of Schwann cells) are called nodes of ranvier.

6.The functional and structural unit of the nervous system is neuron.

7. All the living organisms respond to stimuli.

8. Diencephalon is the centre for emotions, blood pressure, temperature, hungry and sleep.

9. Islets of langerhans (Insulin producer in pancreas) were discovered by Paul Langerhans in 1868.

10. Medulla oblongata controls cardiac, respiratory and vasomotor activities.

11. No. of cranial nerves are 12 pairs and spinal nerves are 31 pairs.

12. The dilation of pupil influenced by autonomous nervous system/ adrenal gland.

13. Adrenaline is also called Fight and flight hormone.

14. Ripening of fruits caused by ethylene.

15. Due to chemo tropism pollen tubes grow to reach ovule.

16. A point of contact between two neurons is synapse.

17. Closing of stomata, seed dormancy is caused by Abscissic acid.

18. Auxins influence the cell elongation, differentiation of shoots and roots.

19. Cytokinins promote cell division, opening of stomata, anti aging of leaves.

20. In 1926 F.W.Went discovered auxins.

21. Gibberellins promote elongation of stems, breaking the seed dormancy.

22. Thyroxin secreted by thyroid is responsible for growth rate and metabolic activity.

23. The nastic movement of touch me not plant is called thigmonasty or thigmo tropism.

24. In 1905 Starling had coined the term hormones which are secreted by ductless glands.

25. The shoots of creepers bends towards sunlight because of photo tropism.