Parts of the Flower (angiosperms)

Petal- Petals are used to attract insects into the flower, they may have guidelines on them and be scented. Stigma- Is covered in a sticky substance that the pollen grains will adhere to. Style- The style raises the stigma away from the Ovary to decrease the likelihood of pollen contamination. It varies in length.

Ovary- This protects the ovule and once fertilization has taken place it will become the fruit. Ovule- The Ovule is like the egg in animals and once fertilization has taken place will become the seed.

Gives support to the flower and elevates the flower for the insects. Flower stalk- Gives support to the flower and elevates the flower for the insects. Nectary- This is where a sugary solution called nectar is held to attract insects. Sepal- Sepals protect the flower whilst the flower is developing from a bud.

This is the stalk of the Anther. Filament- This is the stalk of the Anther. Anther- The Anthers contain pollen sacs. The sacs release pollen on to the outside of the anthers that brush against insects on entering the flowers. Once the pollen is deposited on the insect..it is transferred to the stigma of another flower. The ovule is then able to be fertilized.

Male Parts Female Parts Stamen Anther Filament Pistil Ovary Stigma Ovule Style

2 Types of flowers: Perfect vs. Imperfect a flower that has either all male parts or all female parts Imperfect- EX: cucumbers, pumpkin, and melons a flower that has both male and female parts in the same flower Perfect- EX: roses, lilies, and dandelions

Take another look...

Fruits and Seeds

Fruits

From ovary to fruit The ovary of the flower contains the ovules. As fertilized ovules develop into seeds, the ovary wall develops into the fruit. In science, the term “fruit” refers to a mature ovary that contains seeds.

Fruit anatomy

Types of dry fruits Capsule (Poppy) Legume (Bean pod) Achene (Sunflower) Follicle (Columbine) Silique (Money Plant) Nut (Hazelnut)

Types of fleshy fruits Drupe (Peach) Pome (Apple) Pepo (Cucumber) Berry (Tomato) Aggregate (Strawberry) Multiple (Pineapple)

Fruit dispersal The form of the fruit gives clues about its dispersal. Small, dry fruits with “wings” or “parachutes” may be wind-dispersed. Fleshy fruits are often animal dispersed. Explosive fruits can fling seeds away. Floating fruits may be water dispersed.

How are these fruits dispersed? Dandelion Coconut Maple Cocklebur Jewelweed

Thinking question: Why must fruits be dispersed away from the parent plant?

Seeds

Ovule to seed

Mature Seed

Seed anatomy

Seed dormancy Seeds can remain dormant in the soil for long periods of time. Dormancy helps ensure that seeds only germinate when conditions are right. When we weed or cultivate a bare patch of soil, the weeds that sprout up immediately usually come from the “seed bank” already in the soil.

Breaking dormancy Seeds require moisture and the right temperature to germinate. In addition, some seeds germinate only after certain environmental signals: Drying Temperature (period of cold or heat) Disruption of the seed coat

Thinking question What could be the advantage of waiting for each of these signals to germinate? Long period of cold High heat of a forest fire Drying out Disruption of the seed coat.

Germination: monocot

Germination: dicot

Concept check: Some students confuse pollination with fruit dispersal. Explain the difference. Some students confuse seed germination with plant growth. Explain the difference.