Diffusion of gases occurs in the alveolar region only, and not in the other parts of respiratory system.Why ?

Why does disperson occur only on refraction and not on reflection ?

Mention the various parts of human respiratory system in their connect sequence.

Why do noble gases form compounds with fluorine and oxygen only?

Read the following statement about human respiration. (i) trachea divides at the level of 6th thoracic vertebra (ii) terminal bronchioles alveoli and their ducts form the respiratory part of this system (iii) contraction of diaphragm increases volume of thoracic chamber dorsoventrally (iv) the internal intercostals help in inspiration

Gases diffuse over the respiratory surface because of PO_(2)

(a) State in brief the functions of the following organs in the human female reproductive system: Ovary, Fallopian tube. (b) What is menstruation? Why does it occur?

''We withdraw our leg when stepped on thorn unknowingly." i] Trace the sequences of events which occur in this action. ii] Which part of human nervous system controls this action?

a] Name the parts of the human female reproductive system where i] fertilisation takes place, ii] implantation of the fertilised egg occurs. b] Explain how the embryo gets nourishment inside the mother's body. c] Write the function of following parts in human female reproductive system: i] Ovary ii] Oviduct iii] Uterus d] Describe in brief the structure and function of placenta. OR Explain the structure and important role of placenta during gestation period of woman.

(a) Name the human male reproductive organ that produces sperms and also secretes a hormone. Write the functions of the secreted hormone. (b) Name the parts of the human female reproductive system where- (i) Fertilisation takes place (ii) Implantation of the fertilised egg occurs. (c) Explain how the embryo gets nourishment inside the mother's body.