When the colony of yeast is in water, it does not get nutrition, because water does not have nutrients. Sugar, on the other hand, provides nutrition. Once the yeast gets nutrition, it grows and begins producing buds. That is why, colonies of yeast fail to multiply in water, but multiply in sugar solution.

Gamete formation is the first step in sexual reproduction. Number of chromosomes is halved during gamete formation. As a result, the number of chromosomes in gamete is half the number of chromosomes in somatic cells. When male and female gametes fuse during fertilization, the number of chromosomes becomes equal to that in somatic cells. This explains how, offspring and parents of organisms reproducing sexually have the same number of chromosomes.

An exact copy of something is called a clone. During sexual reproduction, all the traits in an offspring are similar to the traits in the parent. Due to this, offspring formed after sexual reproduction exhibit remarkable similarity.

Unicellular organisms reproduce asexually and often do that by binary fission. Binary fission is similar to mitosis, in which two daughter cells are produced after cell division. Hence, cell division can be considered as a type of reproduction in unicellular organisms.

For a flower to produce fruits, it is necessary that pollination and fertilization take place. In the absence of stamens, as given here, cross pollination must have taken place to facilitate fertilization. The cross fertilization could be assisted by human or by some other agent of fertilization. This would have led to production of fruit.