Reproduction in humans revision igcse_fernando
- 1. Based on the exercises from http://www.biology-resources.com/biology-questions.html Reproduction in humans http://biodeluna.wordpress.com IGCSE Revision Questions
- 2. Which of the following are (a) alive, (b) capable of growing into a new individual: embryo, sperm, fetus, ovum, zygote
- 3. State the differences between the male gametes and the female gametes with regard to their size; their structure, their relative numbers. http://www.ceunit.com/ceus-HumanSexuality
- 4. Explain what is meant by ovulation. (b) How often does it occur in humans? http://www.britannica.com/EBchecked/topic-art/435788/19665/The-ovaries-in-addition-to-producing-egg-cells-secrete-and
- 5. When an ovum and sperms are observed under the microscope, it is seen that the sperms always swim towards the ovum. Which of the following is the best hypothesis to explain this observation? (a) It is necessary for the sperms to reach the ovum if fertilisation is to occur. (b) The sperms know instinctively where the ovum is. (c) The ovum produces chemicals which make the sperms swim towards it. (d) The sperms are attracted to the ovum by some means.
- 6. Explain why the chance of fertilisation in humans is restricted to only a few days each month. http://www.answers.com/topic/menstrual-cycle
- 7. The charts below show the menstrual period, the thickness of the uterus lining and the level of progesterone for the first 14 days of the menstrual cycle. Assuming that ovulation occurs on day 14, complete the charts for the next 20 days (a) assuming that fertilisation takes place (b) assuming that there is no fertilisation.
- 8. Name the male sex hormone and (b) the female sex hormone which help bring about the changes at puberty .
- 9. (a) What are the advantages of human milk over cows' milk for feeding babies? (b) Apart from the composition of the milk, what are the other advantages of breast-feeding?
- 10. (A) vagina, (B) cervix, (C) amnion, (D) uterus, (E) placenta, (F) oviduct, (G) fetus. (i) Ovum matures in ovary, (ii) ovum released from follicle, (iii) sperms deposited at top of vagina, (iv) ovum enters oviduct, (v) sperm fertilises ovum, (vi) embryo implants in lining of uterus.
- 11. Describe the events which lead to the formation of (a) identical twins, (b) fraternal twins. (c) conjoined Twins http://8e.devbio.com/article.php?id=113 http://embryology.med.unsw.edu.au/Defect/images/Smellie_twins.jpg http://www.inkycircus.com/jargon/men_whose_babies_we_want_to_bear_/page/3/
- 13. Why doesn't the fetus drown when it is in the amniotic fluid? Image dbtechno.com
- 14. After ovulation (a) what structure replaces the Graafian follicle, (b) what hormone does it produce?
- 15. Describe how you would design an investigation to find out whether the babies born to women who smoked during pregnancy had lower birth weights than babies born to non-smoking women. Discuss possible sources of error. Image from http://sigmailife.blogspot.com/2009/12/dont-do-it.html