Reproduction is one of the most important characteristics of living beings. Give three reasons in support of the statement.

On cutting the body of an organism into many pieces it was observed that many of these pieces developed as new individuals. Name the process and list two organisms in which this process may be observed. Draw a schematic diagram to illustrate the changes that are likely to be observed during the development of new individuals in any one of the organisms named.

Explain how, new Bryophyllum plants can be produced from the leaves of the old plant ? Illustrate your answer with the help of a labelled diagram.

Explain budding in Hydra with the help of diagrams only.

What is placenta? Describe its two major functions.

What are the three types of methods used for birth control (or regulating child birth)? Give one example of each type.

State the advantages of sexual reproduction over asexual reproduction.

Explain the meaning of sexually transmitted diseases (STDs). Give two examples of STDs each, caused due to,

1. Bacterial infection.
2. Viral infection. State in brief how the spread of such diseases may be prevented.

What is placenta? State its function in human female.

What happens when

1. Planaria gets cut into two pieces?
2. A mature spirogyra filament attains considerable length?
3. On maturation sporangia burst?