(a) What do you call the area of an ovum from where the sperm makes its entry?
(b) Name the enzyme produced by the sperm to facilitate its entry.

(a) The diagram given below is that of a developing human foetus in the womb. Study the same and then answer the questions that follow : (i) Name the parts '1' and '5' indicated by guidelines. (ii) What term is given to the period of development of the foetus in the womb ? (iii) How many days does the foetus take to be fully developed ? (iv) Mention two functions of the part labelled 2 other than its endocrine function. (v) Name the hormone (any one) produce by the part labelled 2 (vi) What is the function of the part marked 3 ? (b) Give the exact location of amnion. [ICSE 2011, 2014]

(a) Name the stage of plasmodium that gains entry into the human body. (b) Trace the stages of in the body of female anopheles after its entry. (c) Explain the cause of periodic recurrence of chill and high fever during malarial attack in humans.

A particle moving with uniform acceleration along a straight line ABC rosses point A at t=0 with a velocity 12 m s^(-1) .B is 40 m away from A and C is 64 m away from A . The particle passes B at t=4 s . a. After what time will the particle be at C ? b. What is its velocity at C ? c. What does the particle reach A again? d. Locate the point where the particle reverses its direction of motion. e. Find the distance covered by the particle in the first 15 s .

Describe the events that take place from the time of entry of the human sperm into the ovum till fertilisation is complete.

(a) Name the organ that produces sperms as well as secretes a hormone in human males. Name the hormone it secretes and write its functions. (b) Name the parts of the human female reproductive system where fertilization occurs. (c) Explain how the developing embryo gets nourishment inside the mother's body.

The diagram given below represents two reproductive cells A and B. Study the same and then answer the questions that follow: (i) Identify the reproductive cells A and B. (ii) Name the specific part of the reproductive system where the above cells are produced (iii) Where in the female reproductive system do these cells unite ? (iv) Name the main hormones secreted by the (1) ovary (2) testes. (v) Name an accessory gland found in the male reproductive system and state the function of its secretion.

Given below is the diagram of a human ovum surrounded by a few sperms. Study the diagram and answer the following questions : (a) Which one of the sperms would reach the ovum earlier ? (b) Identify 'D' and 'E'. Mention the role of 'E'. (c ) Mention what helps the entry of sperm into the ovum and write the changes occuring in the ovum during the process. (d) Name the specific region in the female reproductive system where the event represented in the diagram takes place.

Given below is a diagram of the reproductive system of a human female : (i) Name the parts numbered 1-6. (ii) Normally after how many days does an ovary release an egg? (iii) Where are the sperms released during coitus? (iv) What do the sperms do after being released ? (V) What is the function of the organ numbered 5 ? (vi) How many days does it normally take from the fertilisation of the egg up to the birth of the baby?

Study the diagram given below and then answer the questions that follow : (i) Name the part labelled A. Name any two hormones produced by the part labelled A. (ii) What happens to the part labelled B if : (1) fertilisation takes place? (2) fertilisation does not take place ? (iii) Where does fertilisation occur ? (iv) Draw a neat diagram of the human sperm as seen under high magnification and label the following parts: (a) Acrosome (b) Mitochondria.

A megnetic dipole with a dipole moment of magnitude 0.020 J/T is released from rest in a tutiliform magnetic field of magnitude 52 mT . The rotation of the dipole due to the magnetic force on it is unimpeded. When the dipole rotates through the orientations where its dipole moment is aligned with the magnetic field, its kinetic energy is 0.80 mJ . (a) What is the initial angle between the dipole moment and the magnetic field? (b) What is the angle when the dipole is next (momentarily) at rest?