Seeded vascular plants evolved more than 200 million years ago.

Plants that reproduce by means of seeds do not necessarily require abundant moisture in order to complete their life cycle. The fertilization, as well as seed disbursal of gymnosperms and angiosperms relies on wildlife, as well as wind and water!

AKA Gymnosperms and Angiosperms

When evolving a more terrestrial lifestyle, there were some very obvious hurdles to overcome:• Structural Support•Transport of materials• Fertilization without water• Seed disbursal

The seeds from coniferophytes are found within specially adapted cones, which are disbursed largely through the help of animals.

As a result of all these adaptations, seed plants are able to grow in much drier habitats than are plants that do not have seeds or vascular tissue.

The spermatophytes, which means "seed plants", are some of the most important organisms on Earth. Life on land as we know it is shaped largely by the activities of seed plants. Soils, forests, and food are three of the most apparent products of this group

Male and female cones look quite different.

As with the simpler plants, there is a sporophyte and gametophyte generation in seed plants.

• male and female cones

• microspore/megaspore

• pollen to archegonium

• fertilization (2N)

• seed dispersal

• germination

• sporophyte

Both genders are present on one plant…

Monoecio

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The flowering plants represent the most complex of all seed plants.

They have many adaptations to help spread their pollen.Some angiosperms produce not only flowers, but fruit as well.

A fruit is nothing more than a ripened ovary, with the accompanying seeds within.

Fruits represent a dispersal method that some flowering plants have adapted.

Fruits (in either sense of the word) are the means by which many plants disseminate seeds. Most plants bearing edible fruits, in particular, coevolved with animals in a symbiotic relationship as a means for seed dispersal and nutrition, respectively; in fact, many animals have become dependent on fruits as a source of food. They are known as “frugivores”. Many times,

when fruits are consumed, the seeds are left behind as a waste of the animals. The plants benefit because it helps them to disseminate their seeds…What type of symbiotic relationship?

Mutualism

Again, with angiosperms, there is an alternation between sporophyte and gametophyte generations.

• micro and megaspore production within male and female flower parts

• pollination

• fertilization

• germination of sporophyte

The tiny epicotyl is the embryonic plant shoot just starting to grow.

The seed coat, also called the “testa” is the outer membrane of the seed, which serves to protect the seed from the environmental conditions.

The cotyledon, or seed leaf is what will eventually become the leaves of the plant.

The radicle will become the root of the developing embryo

The hypocotyl is the stem-like embryonic structure below the epicotyl

The endosperm is the nutrient for the developing seedling (stored starch)

Monocots:

• Flower petals in multiples of three• Major leaf veins are

parallel • Vascular bundles are scattered throughout stem

Eudicots:

• Embryo with two cotyledons• Flower petals in multiples of four or five

• Major leaf veins are netted• Vascular bundles arranged in a ring

• Embryo with a single cotyledon

Tomorrow, you’ll be going out into the field. You’ll be finding examples of monocots and eudicots, based on their structure, for part B of the transpiration lab. In your lab group:

• Find one example of each, and pick it.

• Bring inside and put in large beaker for tomorrow

• Sketch each of your chosen plants in your quadrille, identifying it as a monocot or eudicot based upon its structure

• Prepare part B pre-lab for tomorrow