Reproduction

Step 1: Testes are male reproductive organs. Step 2: They produce sperms. Step 3: They also secrete male hormone linked with puberty changes.

Step 1: Ovaries are female reproductive organs. Step 2: They produce ova. Step 3: They also secrete female hormones that control body changes.

Step 1: Sperm is the male gamete. Step 2: It is motile to reach the ovum. Step 3: Ovum is larger and contains material for early development.

Step 1: Sperm and ovum may fuse in the oviduct. Step 2: The zygote divides and reaches the uterus. Step 3: The uterus provides a safe and nourishing place for embryo development.

Step 1: The embryo cannot eat food by itself. Step 2: Placenta helps exchange nutrients and oxygen from the mother's blood. Step 3: It also helps remove wastes from the embryo.

Step 1: The uterine lining thickens for a possible embryo. Step 2: If fertilisation does not occur no embryo forms. Step 3: So the lining breaks down and comes out as menstrual flow.

Step 1: During adolescence the body moves toward maturity. Step 2: Secretion of reproductive hormones increases. Step 3: These hormones affect reproductive organs and secondary characters.

Step 1: During adolescence many external changes appear in boys and girls. Step 2: These changes are controlled by reproductive hormones. Step 3: They are called secondary sexual characters.

Step 1: Contraceptive pills can be hormone based methods. Step 2: They may affect the release of ovum. Step 3: This reduces the chance of pregnancy.

Step 1: Condom is a barrier method. Step 2: It prevents sperm from entering the female reproductive tract. Step 3: It also reduces contact with infected fluids and helps prevent diseases.

Step 1: A copper device is an intrauterine method. Step 2: It is placed in the uterus. Step 3: It reduces the chance of pregnancy.

Step 1: In surgical methods the path of gametes is blocked. Step 2: This can prevent sperm and ovum from meeting. Step 3: Therefore it is considered a long term or permanent method.

Step 1: Pregnancy needs sperm and ovum to meet. Step 2: In sterilisation their path is blocked. Step 3: This reduces the chance of fertilisation.

Step 1: Some infections spread through reproductive tract contact. Step 2: Unsafe sexual contact can increase the risk. Step 3: Safe behaviour and condom use help in prevention.

Step 1: Sperm formation is sensitive to temperature. Step 2: A temperature slightly lower than body temperature is suitable. Step 3: Therefore testes lie in a pouch outside the body.

Step 1: Sperms are produced in testes. Step 2: They need to reach the passage for release. Step 3: Sperm duct transports them.

Step 1: Sperms must move through the female reproductive tract. Step 2: Fluid gives them a medium for movement. Step 3: It can also provide some nourishment and protection.

Step 1: Ovum comes from ovary into the oviduct. Step 2: Fertilisation usually occurs there. Step 3: Further embryo development occurs in the uterus.

Step 1: Fertilisation usually occurs in the oviduct. Step 2: If the oviduct is blocked sperm and ovum cannot meet easily. Step 3: Therefore the chance of pregnancy decreases.

Step 1: If fertilisation occurs an embryo may form. Step 2: The uterine lining remains to support the embryo. Step 3: So it does not come out as menstrual flow.