an investigation was done to determine the role of petals in insect pollination in apple flowers.when flowers are self pollinated,the tubes grow a little into the stigma and style and fertilization does not take place.(1)10 flowers with petals and 10 flowers without petals were used.(2)after 2 days the flowers were prevented from further pollination .(3)after 7 days the extent of pollination an fertilization was recorded.state the hypothesis for this investigation.