Aresearcher has hypothesized that the chemical tributyltin (an additive in boat paint) seeps into the water causing reproductive defects in developing marine snails. in an experiment testing the effects of tributyltin on developing snails, which condition should be used as a control?

              In order to conduct experiment for checking the effect of tributylin on reproductive effects in marine the following treatments should be made

1. control condition:

                                    Consist of marine water having not tributylin .

2. Control condition

                                  Consist of marine water which is filtered and treated with chlorine in order to clean any other chemicals present in water

3. Condition

                    consist of marine water having tributyline

marine snails should be grown in all above mentioned condition and analysis should be carried out at reproductive and post reproductive stages. a comparative study will prove that either tributylin is responsible for reproductive defects or there are some other agents who bring about reproductive defects in snails.  

prophase: we can observe the chromosomes to coil up and condense. they become visible. nuclear membrane and envelope disintigrate.s

metaphase: chromosomes align at the center, the metaphase plate. spindle fibers attach to centromeres of the sister chromatids. they meet at kinetochores.

anaphase: sister chromatids are pulled towards each opposing centromere, set on different poles.

telophase: chromosomes are now clustered up only on either sides of the cell. nuclear membranes reform, and a new cell wall forms along the cell plate. this will lead to cytokinesis, the process that divides the cell membrane and forms the cell wall.