Flowers & Seeds

Life Science - Middle School

Flower parts pistil style stigma ovary eggs petal sepal anther stamen filament sperm travels down tubes to eggs pollen transferred to stigma insect picks up pollen from anthers ovary eggs pollen pollen tubes grow down to ovary seed coat embryo endosperm (cotyledons) germinating seed seedling Flower Pollination & Fertilization In order for a seed to form, pollen has to get from a stamen to a pistil. Insects, animals and wind make this happen. Cross-pollination is the transfer of pollen from the anther of one flower to the stigma of another flower. Self-pollination is the transfer of pollen from anther to stigma on the same flower or to the stigma of another flower on the same plant. Once pollen grains land on a pistil, pollen tubes grow from the pollen through the pistil to the bottom of the ovary. Sperm cells from the pollen travel through the pollen tubes to join the egg cells in the ovary of the flower. The joining of an egg cell with a sperm cell is called fertilization which results in forming a seed. The Structure of a Seed Most plants begin as a seed. The outer layer of a seed is the seed coat which provides protection. The embryo is inside the seed; it’s a new plant ready to germinate. The endosperm is stored food for the new plant. How do seeds get around? Seeds are dispersed in several different ways. Seeds sometimes just fall from the parent flower onto the soil nearby the parent plant. Other seeds are dispersed by animals moving them from one place to another. Still others are eaten by animals and then go through the animal’s digestive system. When the animal rids its body of waste, the seeds are then dispersed in soil where the seeds can germinate when the conditions are right. Germination When the conditions are right, a seed will germinate. Roots will grow out from the seed and down into the soil. The stem of the plant will then grow upwards. This seed travels with the wind. This seed hitches a ride on animal fur. Seeds can be found in all shapes and colors. These seeds might be eaten by animals and transported through their digestive tracts! The Structure of a Flower The flower is the seed factory of the plant it is where the flower produces seeds. A flower’s sepals cover a developing flower bud protecting it while it grows. The petals of a flower are often bright and colorful which aids in pollination by attracting insects and animals to the flower. The stamen is the male organ of a flower and includes the anther and the filament. The anther contains pollen that is a necessary for plant reproduction. The pistil is the female organ of a flower and includes the stigma, style & ovary. Eggs can be found in the ovary. A perfect flower is a flower with both a stamen and a pistil. An imperfect flower is a flower with only a stamen or a pistil but not both. 1 2 3 4 All About Seeds © Copyright NewPath Learning. All Rights Reserved. 9 4-4503 Flowers and Seeds
Key Vocabulary Terms anther pistil dispersal pollen egg pollen tube embryo pollination endosperm seed coat fertilization seedling filament sepal flower sperm germinate stamen ovary stigma petal style All About Seeds Flower Pollination & Fe rtilization Cross-pollination is ___________________________ ____________________________________________ . Self-pollination is _____________________________ ____________________________________________ . Describe the process of pollination: _____________________________________ _____________________________________ _____________________________________ _____________________________________ _____________________________________ _____________________________________ The Structure of a Seed Describe the parts of a seed. __________________________ How do seeds get around? Describe some of the ways that seeds are dispersed. __________________________ __________________________ __________________________ Germination Describe the process of germination. ___________________________________________________________ ___________________________________________________________ The Structure of a Flower What is the purpose of a flower? ________________ ___________________________________________ Describe the following plant structures: Eggs ________________________ Ovary _______________________ Petals _____________________________________ Pistil ______________________________________ Sepals ____________________________________ Stamen ___________________________________ What is a perfect flower? _____________________ ___________________________________________ What is an imperfect flower? __________________ __________________________________________ 1 2 3 4 © Copyright N ewPath Learning. All Rights Reserved. 94-4503 Flowers and Seeds Flower parts \|xiBAHBDy01714rzu