By Frank H. Osborne, Ph. D. Lab 10 - Flowers and Fruits Principles of Biology By Frank H. Osborne, Ph. D. Lab 10 - Flowers and Fruits

Flowers A. The flower is the reproductive structure of the plant. 1. Many flowers contain both male and female reproductive parts. 2. Some species of plants have only one type of flower on a plant. These species have male and female plants. An example is Holly.

Holly (separate plants) Corn (separate locations) Flowers Male Flower (Tassel) Holly (separate plants) Corn (separate locations) Female Flower (Silks)

B. Parts essential for reproduction 1. Female parts - the pistil a. Ovary i. The ovary is at the base of the pistil. ii. The ovary may have one or more chambers. iii. The ovary contains ovules which are the unfertilized female structures containing the egg.

B. Parts essential for reproduction 1. Female parts - the pistil b. Style i. The style is a conduit connecting the ovary to the stigma. ii. Pollen grains travel through the style.

B. Parts essential for reproduction 1. Female parts - the pistil c. Stigma i. The stigma is found at the end of the pistil. ii. The pollen stick to the stigma then send nuclei into the style and, through the style, to the ovary.

B. Parts essential for reproduction 2. Male parts - the stamens a. Anther i. The anther produces pollen which are the male reproductive structures of the plant.

B. Parts essential for reproduction 2. Male parts - the stamens a. Anther ii. The pollen fertilize the ovules by being attached to the stigma, traveling through the style into the ovary, and entering the ovules. b. The filament supports the anther.

C. Parts that are not essential for reproduction 1. Bract The bract is a structure that protects the immature flower. 2. Stalk a. The stalk is called a pedicel. b. The top part of the pedicel is called the receptacle. The flower is attached to the receptacle.

C. Parts that are not essential for reproduction 3. Sepals a. In many flowers, these protect the immature flower parts while they are developing. b. Sometimes they are green, sometimes they are the same color as the petals.

C. Parts that are not essential for reproduction 3. Sepals c. They are found outside the petals. d. There are generally three or five sepals in a flower.

C. Parts that are not essential for reproduction 4. Petals a. In many flowers, the petals are brightly colored to attract insects. b. They are found inside the sepals. c. There are generally three or five petals in a flower.

Snapdragon flower

Gladiolus flower

Pollination A. Pollen is produced in the anther. B. Pollen must get to the stigma in order to fertilize the flower. 1. Some flowers are pollinated by the wind. An example is grass. 2. Some flowers are pollinated by insects. 3. Some flowers can pollinate themselves.

Fruit Development A. After fertilization, the ovary of the flower develops into a fruit. B. Inside the fruit, the fertilized ovules develop into the seeds.

Dispersal of Seeds A. Wind dispersal 1. Some plants use wind to spread their seeds. 2. Their seeds are light and easily blown away. 3. Examples are maple trees and dandelions.

B. Animal dispersal 1. Acorns are the fruits of oak trees. The acorns are buried in the ground by squirrels. 2. Animals eat fruit, such as apples, and the seeds are deposited elsewhere.

The End Lab 10 Flowers and Fruits