Reproduction

Step 1: Copying gives offspring parent like information. Step 2: Small errors can create variation. Step 3: Too many errors can damage essential traits.

Step 1: Asexual offspring are similar to the parent. Step 2: Because of similarity they may share the same weakness. Step 3: A changing environment can affect the whole population.

Step 1: Nuclear division is necessary in binary fission. Step 2: Division of cytoplasm and separation of cells are also needed. Step 3: Without separate cells the process is not complete.

Step 1: In multiple fission genetic material can divide many times first. Step 2: Cytoplasm later divides around these parts. Step 3: This forms many daughter cells.

Step 1: In budding a small outgrowth forms on the parent body. Step 2: The outgrowth needs nutrition to grow. Step 3: After development it can separate as a new organism.

Step 1: Spirogyra is a simple filament like organism. Step 2: Its pieces can grow into new filaments. Step 3: In complex animals organs are specialised so every piece cannot form a whole organism.

Step 1: Repair only heals a damaged part. Step 2: In regeneration a small part of some organisms can form a whole body. Step 3: So it is not only wound healing.

Step 1: Spores are small and can spread. Step 2: Survival in difficult conditions can be challenging. Step 3: Thick walls protect them until conditions become favourable.

Step 1: Not all spores reach a suitable place. Step 2: If many spores are formed some may reach a moist food rich place. Step 3: This improves reproductive success.

Step 1: In vegetative propagation new plants arise from parts of the same parent. Step 2: Their traits can be very similar. Step 3: If weakness to a disease is shared many plants may be affected.

Step 1: In vegetative propagation a plant part forms a new plant. Step 2: The new plant is usually like the parent. Step 3: So identical copies of a good variety can be obtained quickly.

Step 1: Potato eyes are buds. Step 2: New shoots arise from these buds. Step 3: Without an eye the chance of forming a new plant decreases.

Step 1: Small buds form on margins of Bryophyllum leaves. Step 2: These buds can fall on soil and grow. Step 3: So this is seedless vegetative propagation.

Step 1: In sexual reproduction male and female gametes fuse. Step 2: Genetic information from both enters the new offspring. Step 3: This creates variation that can help the species.

Step 1: In self pollination pollen comes from the same flower or same plant. Step 2: Genetic mixing remains limited. Step 3: Cross pollination can increase variation by mixing information from different plants.

Step 1: Pollination only means pollen reaches the stigma. Step 2: Fertilisation needs the male gamete to reach the ovule. Step 3: If pollen tube fails fertilisation will not occur.

Step 1: Pollen from the correct species is needed for successful fertilisation. Step 2: Pollen from a wrong species may not germinate properly on stigma. Step 3: If the male gamete does not reach ovule seed will not form.

Step 1: Removing stamens prevents that flower from producing pollen. Step 2: If pistil is intact the stigma can receive outside pollen. Step 3: Suitable pollen can lead to fertilisation and seed formation.

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

Step 1: Pollination brings pollen to the stigma. Step 2: Fertilisation is needed for seed formation. Step 3: Without female gamete zygote and embryo cannot form.

Step 1: Water activates the seed. Step 2: The active embryo needs energy for growth. Step 3: Air is needed for respiration to obtain energy.

Step 1: Testes produce sperms. Step 2: Sperm production is better at slightly lower temperature than body temperature. Step 3: Scrotum helps maintain this suitable temperature.

Step 1: Testes produce sperms. Step 2: Sperm duct is the passage carrying sperms forward. Step 3: If the passage is blocked sperms cannot reach the ovum.

Step 1: Sperms need to move through the female reproductive tract. Step 2: Fluid medium helps movement. Step 3: It also provides nourishment and protection so deficiency can reduce success.

Step 1: Ovary produces ovum. Step 2: Fertilisation usually occurs in the oviduct. Step 3: A blocked oviduct prevents sperm and ovum from meeting.