Reproduction

Step 1: Water helps the seed swell and become active. Step 2: Air is needed for respiration. Step 3: Suitable temperature allows growth processes to work properly.

Step 1: Sperms are produced in testes. Step 2: Testes also produce male hormones. Step 3: These hormones are linked with many changes during puberty.

Step 1: Sperms are formed in testes. Step 2: Slightly lower temperature than normal body temperature helps sperm formation. Step 3: Therefore testes are present in a sac outside the body.

Step 1: The sperm duct carries sperms forward. Step 2: Hormone production occurs in cells of the testes. Step 3: Therefore cutting the duct blocks sperm passage but hormone production is a different process.

Step 1: Eggs are produced in ovaries. Step 2: Ovaries also produce female hormones. Step 3: These hormones are linked with reproductive cycle and puberty changes.

Step 1: During ovulation the egg is released from the ovary. Step 2: It enters the fallopian tube. Step 3: Fusion with sperm usually occurs in this tube.

Step 1: Fusion of male and female gametes forms a zygote. Step 2: The zygote divides repeatedly. Step 3: The group of divided cells develops into an embryo.

Step 1: The embryo needs nutrients and oxygen for growth. Step 2: Attachment to the uterine wall allows exchange of materials. Step 3: This supports safe development of the embryo.

Step 1: The embryo cannot take food by itself. Step 2: It receives nutrients and oxygen from the mother. Step 3: Placenta also helps in removal of wastes.

Step 1: The uterus prepares an inner lining for pregnancy. Step 2: If pregnancy does not occur this lining is not used. Step 3: The lining comes out with blood and this is menstruation.

Step 1: The body begins to mature during adolescence. Step 2: Hormones control many body changes. Step 3: Voice change hair growth and other characters are linked with this.

Step 1: Condom prevents sperm from reaching the egg. Step 2: It can also reduce direct contact. Step 3: Therefore it helps prevent unwanted pregnancy and some infections.

Step 1: Copper T is placed in the uterus. Step 2: It can reduce the chance of pregnancy. Step 3: Some pills act on hormones and affect ovulation.

Step 1: Surgery is done on sperm duct in males or fallopian tube in females. Step 2: This blocks the route of gametes. Step 3: Therefore it is considered a long term contraceptive method.

Step 1: Two gametes fuse in sexual reproduction. Step 2: If each carries half number their fusion restores the normal number. Step 3: This keeps chromosome number stable across generations.

Step 1: Two gametes fuse in fertilisation. Step 2: If both provide full number the total will exceed normal. Step 3: Therefore half number maintains stability in reproduction.

Step 1: Sexual reproduction can combine information from two parents. Step 2: This creates new genetic combinations. Step 3: Variation increases the chance of adaptation in changing environments.

Step 1: In asexual reproduction offspring form from one parent. Step 2: Large new combinations of genetic information usually do not form. Step 3: Therefore variation may be low.

Step 1: Stamen is the male reproductive part. Step 2: Pistil is the female reproductive part. Step 3: A flower with only stamens is male and a flower with both is bisexual.

Step 1: Pistil is the female reproductive part of flower. Step 2: Stamen is the male reproductive part. Step 3: If only pistil is present the flower is female.