Reproduction

Step 1: Cutting is vegetative propagation. Step 2: A part of the same plant forms a new plant. Step 3: Thus qualities of a good variety can be maintained.

Step 1: Potato eyes are actually buds. Step 2: The new plant sprouts from these buds. Step 3: Without an eye sprouting is very unlikely.

Step 1: Bryophyllum leaves have buds on margins. Step 2: These buds can form new plants without seeds. Step 3: Therefore it is vegetative propagation not seed reproduction.

Step 1: Sexual reproduction combines genetic information from two parents. Step 2: This fusion creates new combinations. Step 3: Variation can be useful in changing environments.

Step 1: Successful reproduction needs compatible pollen and stigma. Step 2: Pollen from another species may not germinate or grow properly. Step 3: So the male gamete may not reach the ovule.

Step 1: In pollination pollen reaches the stigma. Step 2: For fertilisation the male gamete must reach the female gamete inside the ovule. Step 3: The pollen tube provides this path.

Step 1: In self pollination pollen reaches the stigma of the same plant. Step 2: This can limit genetic mixing. Step 3: Cross pollination involves different plants and may increase variation.

Step 1: Stamen is the male part and produces pollen. Step 2: Pistil is the female part and contains ovules. Step 3: Suitable pollen from another flower can still fertilise it.

Step 1: Ovules are present inside the ovary. Step 2: After fertilisation ovules become seeds. Step 3: The ovary becomes fruit so seeds remain inside the fruit.

Step 1: The ovule contains the female gamete. Step 2: After fertilisation the ovule becomes a seed. Step 3: Unhealthy ovules affect seed formation.

Step 1: Water activates the seed. Step 2: The growing embryo needs energy. Step 3: Respiration is needed for energy so air is required.

Step 1: Sperm production is sensitive to temperature. Step 2: A temperature slightly lower than body temperature is suitable. Step 3: The scrotum helps maintain such temperature for testes.

Step 1: Sperms are produced in testes. Step 2: Sperm ducts carry them forward. Step 3: If the duct is blocked sperms cannot reach the ovum.

Step 1: Sperms need to move through the female reproductive tract. Step 2: Fluid medium helps their movement. Step 3: The fluid also provides some nourishment and protection.

Step 1: The ovary produces ovum. Step 2: Fertilisation usually occurs in the oviduct. Step 3: A blocked oviduct makes meeting of sperm and ovum difficult.

Step 1: After fertilisation the zygote divides. Step 2: The embryo reaches the uterus. Step 3: The thick uterine lining provides a suitable place for development.

Step 1: The uterine lining helps the embryo attach. Step 2: It also supports early nourishment and protection. Step 3: A weak lining can affect embryo development.

Step 1: Placenta provides close contact between mother and embryo. Step 2: Nutrients and oxygen pass across thin surfaces to the embryo. Step 3: Wastes from embryo can pass toward the mother.

Step 1: In each cycle the uterus prepares for possible pregnancy. Step 2: So its lining becomes thick. Step 3: If fertilisation does not occur the lining breaks and comes out.

Step 1: In pregnancy the embryo attaches to the uterine lining. Step 2: This lining is needed for embryo development. Step 3: Therefore it does not break down and come out.