IGCSE Biology Paper-3: Specimen Questions with Answers 303 - 304 of 358
Passage
Question 303 (1 of 1 Based on Passage)
Write in Short
Short Answer▾Using a label line and the letters given, label the diagram.
(i) P where gametes are formed
(ii) Q the sperm duct
(iii) R where testosterone is formed
(iv) S the urethra
Explanation
Question 304
Write in Short
Short Answer▾The list shows four different methods of birth control.
State the name of the method that these types of birth control belong to:
Use of a condom …
Vasectomy …
Use of a contraceptive pill …
Explanation
Barrier Methods
ovum and sperms are prevented from physically meeting with the help of barriers. Such methods are available for both males and females.
- Condoms: Condoms are barriers made of thin rubber/latex sheath that are used to cover the penis in the male or vagina and cervix in the female, just before coitus so that the ejaculated semen would not enter the female reproductive tract. This can prevent conception.
- Surgical Methods: Also called sterilization. Generally advised for the male/female partner as a terminal method to prevent any more pregnancies. Surgical intervention blocks gamete transport and thereby prevent conception. Sterilization procedure in the male is called ‘vasectomy.’ In vasectomy, a small part of the vas deferens is removed or tied up through a small incision on the scrotum whereas.
Oral Contraceptives
Administration of small doses of either progestogens or progestogen – estrogen combinations are another contraceptive method used by the females. They are used in the form of tablets and hence are popularly called the pills. Pills must be taken daily for a period of 21 days starting preferably within the first five days of menstrual cycle. After a gap of 7 days (during which menstruation occurs) it must be repeated in the same pattern till the female desires to prevent conception. They inhibit ovulation and implantation as well as alter the quality of cervical mucus to prevent/retard entry of sperms. Pills are very effective with lesser side effects and are well accepted by the females.