The Pollination Story Diversity of Life Grade 7

The Pollination Story  The ovary of the flower is where the seeds develop.

The Pollination Story  As we know, the seeds contain an embryo, which is the living baby plant that has the potential to grow into a new baby plant.  Seeds start as ovules,  tinypreseeds in the ovary.

 The ovary is located at the base of the pistil in the center of the flower. The Pollination Story

 Inside each ovule is a single, female sex cell, the egg.

The Pollination Story  Some plants have one ovule in the flower, such as a peach or cherry flower.  Other plants have hundreds of ovules in the flower, such as a watermelon or tomato flower.

The Pollination Story  Before an ovule can develop into a seed, the egg must be fertilized.  An egg is fertilized when it joins with a male sex cell, the sperm.

The Pollination Story  The sperm cell is inside the pollen grain. Pollen grains are produced by the plant in the anthers at the tips of the stamens.

The Pollination Story  The process by which pollen gets from the male anther to the female pistil is called pollination.

The Pollination Story  Pollination is complete when a pollen grain, carried by air or an animal, lands on the sticky tip of the pistil, the stigma.

The Pollination Story  The pollen grain germinates and grows a root-like structure that goes down the length of the pistil. This is called the pollen tube.  The sperm cell from the pollen grain travels down the pollen tube into the ovule, and penetrates the membrane of the egg cell.

The Pollination Story  The contents of the two sex cells mix together, forming a single, fertilized cell.  The fertilized cell is alive and has the potential to develop into a new plant.

The Pollination Story  Sexual reproduction happens when a female sex cell (egg) and a male sex cell (sperm) merge to form a single cell with information from both the male and the female.

The Pollination Story

 Plants don’t get around much. In an egg must be fertilized by pollen from a different flower, how does that happen?  How does the pollen get from one flower to another?

The Pollination Story  Please read Flowers to Seed on page 40 of your science resource book to discover the answer.