Question
Q.1 what is unisexual flower? can a unisexual flower be self pollinated? please clear my doubt.

Answer
These unisexual flowers are on the same plant, the plant is "monoecious," meaning one house. If the plant has both on the same plant then it can pollinate itself. But is the plant has only one type of flower (male or female) it will need another plant of different sex to pollinate.

Monoecious - an individual that has both male and female reproductive units (flowers, conifer cones, or functionally equivalent structures) on the same plant; from Greek for "one household". Individuals bearing separate flowers of both sexes at the same time are called simultaneously or synchronously monoecious. Individuals that bear flowers of one sex at one time are called consecutively monoecious;

Dioecious - refers to a plant population having separate male and female plants. That is, no individual plant of the population produces both microspores and megaspores; individual plants are either male (producing microspores) or female (producing megaspores).[5] From Greek for "two households". [Individual plants are not called dioecious; they are either gynoecious (female plants) or androecious (male plants).]
Androecious - plants producing male flowers only, produce pollen but no seeds, the male plants of a dioecious population.
Gynoecious - plants producing female flowers only, produces seeds but no pollen, the female of a dioecious population. In some plant populations, all individuals are gynoecious with non sexual reproduction used to produce the next generation.