Fill in the Blanks Plant reproduction Online version Fill in the blanks plant reproduction activity by LATAM Global School 1 ovary fertilisation stigma tube nucleus grain ovule pollen ovule 1 . As the pollen sits on the , a pollen grows out of the pollen through the stigma and style and down into the . 2 . The of the cell travels down the tube into the ovary . 3 . The nucleus of the pollen cell meets the nucleus of the . This is when occurs . 4 . This fertilised will eventually develop into a new plant .