Reproduction

Step 1: In asexual reproduction genetic material is copied from one parent. Step 2: Small errors can occur during copying. Step 3: These errors can cause limited variation.

Step 1: Binary fission forms two cells from one cell. Step 2: Multiple nuclei and many daughter cells indicate multiple fission. Step 3: Identify the method by the number of offspring cells.

Step 1: Nuclear division divides genetic information. Step 2: Cytoplasmic division forms two separate cell bodies. Step 3: Binary fission is complete only when both divisions occur.

Step 1: In budding an outgrowth forms on the parent body. Step 2: It grows by receiving nutrition from the parent. Step 3: After enough development it can separate as a new organism.

Step 1: In fragmentation a broken part must form a new organism. Step 2: In complex organisms every part does not have this ability. Step 3: So fragmentation is more successful in simpler organisms.

Step 1: Wound healing only repairs the injured part. Step 2: In Planaria a small piece can form a whole organism. Step 3: Therefore it is a clear example of regeneration.

Step 1: Fungal spores are small and can spread. Step 2: They can remain protected for some time in difficult conditions. Step 3: Under favourable conditions they form new fungi.

Step 1: Spores have the ability to form new organisms. Step 2: But germination needs conditions like moisture and food. Step 3: In a dry place germination may not occur.

Step 1: In vegetative propagation new plants form from parts of one parent. Step 2: They often have very similar traits. Step 3: If they share the same weakness disease can spread fast.

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.