 Let's explore sexual reproduction in flowering plants and to begin with let's start by looking at the reproductive parts. So the two main reproductive parts are the male part which is called the stamen and the female part which is called the carpal or the pistol. Now one way I remember the stamen is the male reproductive part because there's the word men in it and that kind of helps me remember it. When it comes to female you might be wondering what is it the same thing carpal and pistol it's not really and the difference can be seen when we have multiple carpals. So some flowers have more than one carpals like what you see over here but they are fused together. In this case we will say it has three carpals but there is only one pistol because they're fused to form one pistol. So you can think of pistol as a team of carpal here I have one team of three carpals but it's also possible for us to have the three carpals which are separate which are not fused together. In this case we will say three carpal three pistol so because we have three different teams but we don't have to worry too much about because we'll not deal with such complicated flowers. Anyways if we further look at the male parts the male part stamen has actually two sub parts you have the long filament and then on top of the filament contains the anther and you can see small dots that are put over there that's the pollen grains that contains the male germ cells the sperm cells and similarly the female part also has sub parts carpal also has sub parts the top part which is very sticky which is where the pollen grain is supposed to sit that's called the stigma then there is this long style then finally we have the ovary the ovary contains the excels you can see tiny tiny tiny structures over here that's where the excels sit and for sexual reproduction somehow the sperm cells inside the pollen grain is supposed to come and reach the excels inside the ovary and we'll see how that happens soon but before we do that you may be wondering can flowers have both the male and the female parts together well some flowers to others don't there are some flowers like for example the flower of lily which has both the male which parts which you can see over here you can see the stamen you can see the nice yellow anther and it contains the carpals you can see the carpal over here it's a little hard to see it contains both such flowers are called bisexual flowers and most usual flowers that you think of like rose lilies sunflowers they're all bisexual flowers on the other hand if you look at the flowers of a papaya tree what you see over here is only the carpals you can only see the carpals over here in fact if you look closely you can see two carpal fused together so one pistol two carpal another pistol two carpal but again no worry so you only see female parts over here but on another papaya flower you can see only again you can see the nice yellow male anthers so this is the male flower so these are the flowers that only contain a female or male parts so these are unisexual flowers and when it comes to unisexual think big fruits and big vegetables like watermelon pumpkin papaya these are all usually having unisexual flowers now let's come back to our question how does a sperm cell inside these pollen grains reach the excels inside the ovary well for that there needs to be pollination is where the pollen grains go and sit on top of the stigma and there are a few ways in which that can happen so for example one way that can happen is when the pollen grains from one flower sits on the stigma of that very same flower that's one possibility another possibility is the pollen grains from one flower goes and sticks to the stigma of another flower but of the same plant or of the same tree and the third possibility is that you can have the pollen grains from one flower goes and sits on the stigma of a different flower from a different tree altogether or a different plant altogether so all these are pollinations but the first two is called self-pollination why self because it is happening within the same plant within the same flower or within the two different flowers of the same tree whatever it is same plant and in the third case because it's happening between two different plants or two different trees we will call this cross pollination now of course cross does not mean a cross species no no no same species obviously a lily flower has to pollinate with another lily flower only the cross means it's a cross to different plants or two different trees but how does it how does the pollination happen well it usually happens via wind or it can happen by insects insects love to sit and suck the nectar from the flower right so that time the pollen grains can get stuck to them and when they go and sit on a different flower it's possible that the pollen grains get stuck to the stigma but what happens next for that let's zoom in we have the pollen grain sitting on the stigma that's pollination and we have the sperm cells inside the pollen grain and we have the excels inside the ovary over here how does this reach over here well for that the pollen grain germinates and there is a tube that comes and the tube eventually finds its way towards the excels and then inside the tube the sperm cells travel they travel travel travel travel all the way and then finally reach and meet the excels and when that happens we say fertilization has happened the two cells unite to form a new cell and this new united new cell formed due to the you know due to the sperm cell and the excel uniting that new cell now is called the zygote the zygote keeps multiplying eventually it becomes a tiny baby plant which we call the embryo and the embryo eventually gets protected inside a seed and during this time we will find that the entire ovary swells up and that eventually becomes the part of the fruit and that's why we usually find the seed to be inside these fruits and then we animals eat the fruit and then the seed finds its way on the ground and when the conditions are right the seed can start germinating and eventually this plant can grow and form its own flowers and the cycle repeats amazing isn't it