Reproduction

Step 1: Cross pollination involves two plants. Step 2: Pollen moves from one plant to the stigma of another plant of the same species. Step 3: This can increase variation.

Step 1: After pollination the male gamete can reach the female gamete. Step 2: Their fusion forms a zygote. Step 3: This fusion is called fertilisation.

Step 1: Fertilisation involves fusion of male and female gametes. Step 2: Their fusion forms a new cell. Step 3: This cell is called a zygote.

Step 1: The ovule is present inside the ovary. Step 2: After fertilisation an embryo develops in it. Step 3: Therefore the ovule becomes a seed.

Step 1: The ovary of a flower contains ovules. Step 2: After fertilisation ovules become seeds. Step 3: The ovary grows into a fruit.

Step 1: A seed contains an embryo. Step 2: For germination it needs water air and suitable temperature. Step 3: Under favourable conditions a new plant comes out.

Step 1: The male reproductive system in humans produces sperms. Step 2: Sperm is the male gamete. Step 3: It can fuse with the ovum during fertilisation.

Step 1: The female reproductive system produces ova. Step 2: Ovum is the female gamete. Step 3: It can fuse with sperm to form a zygote.

Step 1: Testes are main organs of the male reproductive system. Step 2: Testes produce sperms. Step 3: Therefore sperms are produced in testes.

Step 1: Ovaries are main organs of the female reproductive system. Step 2: Ovaries produce ova. Step 3: Therefore ova are produced in ovaries.

Step 1: The ovum moves from ovary into the oviduct. Step 2: Sperm may meet the ovum there. Step 3: Therefore fertilisation usually occurs in the oviduct.

Step 1: After fertilisation the zygote divides to form an embryo. Step 2: The embryo attaches to the wall of the uterus. Step 3: Further development occurs in the uterus.

Step 1: The embryo develops in the uterus. Step 2: It needs food and oxygen from the mother's blood. Step 3: Placenta helps in this exchange.

Step 1: During adolescence the body moves toward reproductive maturity. Step 2: Hormone secretion increases at this time. Step 3: These hormones control body changes.

Step 1: The ovary may release an ovum periodically. Step 2: The uterine lining also prepares for pregnancy. Step 3: If pregnancy does not occur this lining breaks and comes out.

Step 1: The uterine lining thickens to support an embryo. Step 2: If fertilisation does not occur no embryo forms. Step 3: The lining then comes out as menstrual flow.

Step 1: Contraception reduces the chance of pregnancy. Step 2: It helps in family planning. Step 3: So its main purpose is to prevent unwanted pregnancy.

Step 1: A condom is a barrier method. Step 2: It prevents sperm from entering the female reproductive tract. Step 3: It can also help protect from many sexually transmitted diseases.

Step 1: Some contraceptive methods are temporary. Step 2: In surgical methods reproductive tubes are blocked. Step 3: Therefore this is considered a permanent method of contraception.

Step 1: Some diseases spread through contact of reproductive organs. Step 2: Unsafe sexual contact with an infected person increases risk. Step 3: Safe behaviour helps in prevention.

Step 1: First sperm and ovum fuse. Step 2: The zygote divides to form an embryo. Step 3: The embryo attaches in the uterus and develops further.

Step 1: After reaching the stigma the pollen grain germinates. Step 2: A pollen tube forms from it. Step 3: It carries the male gamete to the ovule.

Step 1: Sexual reproduction involves two parents. Step 2: Genetic information from both enters the offspring. Step 3: This creates new combinations and variation.

Step 1: In asexual reproduction one parent may be enough. Step 2: In sexual reproduction male and female gametes fuse. Step 3: Therefore they differ in number of parents and variation.

Step 1: Reproduction produces new organisms. Step 2: It can occur by asexual or sexual methods. Step 3: Its main importance is maintaining continuity of the species.