Notes: Vascular Seed Plants Vascular Plants= possess both xylem and phloem to conduct materials throughout the plant. Seed= a containing the offspring of the plant. Seeds provide two reproductive advantages: Protects plant embryo from drying out Allows for dispersal

Vascular seed producing plants are divided into the two groups seen below: 1. Gymnosperm (naked seed)- Examples include: Pine trees, spruce trees Most are evergreen meaning they have leaves all year round and are adapted to the cold. Possess needle-like or scale-like leaves. Seeds usually in cones Pollination is usually by the wind (hence no bright shiny flowers)

2.Angiosperms (Flowering plants)- Examples include: grasses, dogwoods, rosebush Largest and most diverse group of plants on Earth: 230,000 species Flowers are organs of reproduction

Pistil is the female reproductive organ made of 3 parts: Stigma: top of pistil and is sticky to catch pollen Style: long tube connecting stigma to ovary Ovary: contains eggs (ovules) that when fertilized will develop into seeds

The female reproductive organ develops into a fruit with seeds inside. Ex. Apples, tomatoes (fleshy fruits), peanuts, sunflowers and walnuts (dry fruits)

Stamen is the male reproductive organ. Anther- produces pollen (which is plant sperm in a protective coat) Filament- holds anther up in the air (like a long, thin stem)

Other parts of the flower: (which are not male or female) Sepals: modified leaves that protect flower bud until it opens. Petals: brightly colored to attract pollinators such as birds and bats.

Flowering plants are divided into two classes (each names after the number of leaves or cotyledons that emerge from the seed when they first germinate)

1. Monocots (which is short for Monocotyledon): Single cotyledon

Parallel veins

Floral parts in multiples of 3

Vascular bundles scattered

Fibrous roots

2. Dicots: (which is short for Dicotyledon)

Two cotyledons

Branched veins

Floral parts in multiples of 4 or 5

Vascular bundles arranged in a ring

Taproot

Seed and Fruit Development Pollination occurs when pollen is transfered from anther to stigma. A fertilized egg forms into an embryo inside of a seed. In an angiosperm the ovary ripens and forms into a fruit around the seed.

Plants have evolved to produce fruits of many shapes and sizes, each with the purpose to help disperse or spread the seeds. Characteristics of seeds dispersed by: Wind and water- light weight and or buoyant (can float) Animals- seeds are covered in an edible fruit or have hooks to stick to fur.

Once seeds are dispersed, they often enter a state of dormancy- when plant embryo is alive but not growing Environmental factors that cause a seed to end dormancy are: moisture and temperature Several adaptive advantages of dormancy in seeds include: Long distance dispersal Allows seed to germinate under ideal growth conditions