The reproductive parts of angiosperms are located in the flower.Stamens and carpels r the reproductive parts of a flower which contain the germ- cells.the 
flower may be uni sexual(papaya,watermelon) when it contains either stamens or
carpels or bisexual(Hibiscus,Mustard)when it contains both stamens and carpels
stamen is the male reproductive part and it produces pollen grains that are yellowish in must have seen this yellowish powder that often sticks
to our hands if we touch the stamen of a flower.Carpel is present on the center 
of a flower and is the female reproductive part.
                                  thus,pollen needs to be transferred from the stamen to
the stigma.on the other hand,if the pollen is transferred from one flower to another 
it is known as cross pollination.this transfer of one flower to another is achieved by wind, water or animals.
             after the pollen lands on a suitable stigma ,it has to reach the female
germ-cells which r in the ovary.for this,a tube grows out pollen grain and travels through the style to reach the ovary.
                after fertilization, the zygote divides several times to form an embryo within the ovule. the ovule develops a tough coat and is gradually converted into a seed.the ovary grows rapidly or ripens to form a fruit.Meanwhile, the
petals, sepals, stamens, style and stigma may shrivel and fall off.