Seed Plants

Stem consists of

-An alternating system of nodes, the points at which leaves are attached -Internodes, the stem segments between nodes

root functions

-Anchoring the plant -Absorbing minerals and water -Storing organic nutrients

Parenchyma Cells

-Have thin and flexible walls -Are the least specialized -Perform the most metabolic functions -Retain the ability to divide and differentiate

The vascular tissue of a stem or root is collectively called the stele

-In angiosperms the stele of the root is a solid central vascular cylinder -The stele of stems and leaves is divided into vascular bundles, strands of xylem and phloem

Lateral meristems

-Lateral meristems add thickness to woody plants, a process called secondary growth

Common Types of Plant Cells

-Parenchyma -Sclerenchyma -Water-conducting cells of the xylem •Tracheids •Vessel elements -Sugar-conducting cells of the phloem •Sieve tube members Companion cells

What do each growth produce?

-Primary growth produces the primary plant body, the parts of roots and shoots produced by apical meristems -Secondary growth produces the secondary plant body, the tissues produced by the vascular cambium and cork cambium

Convergence also occurred

-Water-conducting cells evolved independently in mosses and in the vascular plants -Vessel elements evolved independently in gametophytes and angiosperms

The two vascular systems are xylem and phloem

-Xylem conveys water and dissolved minerals upward from roots into the shoots -Phloem transports organic nutrients from where they are made to where they are needed

Five major groups of gymnosperms are living today:

1. Cycadophyta (cycads) 2. Ginkgophyta (ginkgos) 3. Gnetophyta (gnetophytes) 4. Pinophyta (pines, spruces, and firs) 5. Other cone-bearing species (redwoods, junipers, yews)

Two major lineages of Seed Plants

1. Gymnosperms (naked seed) produce seeds that do not develop in an enclosed structure ● 2. angiosperms (seed vessel), seeds develop inside a protective structure called a carpel

General Structure of the Flower

1. Sepals: leaf-like structures; outermost part of the flower 2. Petals: brightly colored; advertise flower to pollinators 3. Stamens: reproductive structures that produce male gametophytes (pollen grains), which in turn produce sperm 4. Carpels: produce female gametophytes, which in turn produce eggs

The diversification of angiosperms is associated with three key adaptations

1. Vessel elements 2. Flowers 3. Fruits

Each stamen consists of

1.A stalk called the filament. ● 2.Pollen-producing organs called anthers.

The carpel consists of

1.The stigma, the moist tip that receives pollen. ● 2.A slender stalk called the style. ● 3.The ovary at the base of the carpel.

axillary bud

A structure that has the potential to form a lateral shoot, or branch.

Gymnosperms

Gymnosperms are plants that have seeds and vasculature Most gymnosperms have only tracheids that move water

Seeds mature as the embryo develops

Inside the seed, cells derived from the female gametophyte become packed with nutrients provided by the sporophyte

occur in the anther.

Meiosis and pollen formation

Bryophytes

Mosses, liverworts, and hornworts These seedless, non-vascular plants, the gametophyte stage is dominant

Seed Germination

Once a seed reaches a location with appropriate conditions it will germinate unless it is dormant

Angiosperm involves two sperm cells

One sperm fuses with the egg to form the zygote, while a second sperm fuses with two nuclei in the female gametophyte to form a triploid (3n) nutritive tissue called endosperm

stratification

Seeds of some temperate forest trees need to be kept at temperatures < 450F

scarification

Some seeds need to go through the digestive system of an animal before they will germinate

Gnetophyta

The gnetophytes comprise about 70 species in three genera. 1. Vines and trees from the tropics. 2. Desert-dwelling shrubs in southwestern North America. 3. Welwitschia, an unusual plant with only two large leaves found in southwestern African deserts. •Gnetophytes have vessel elements in addition to tracheids.

nectary

The nectary produces nectar, which is harvested by many of the animals that visit flowers. located at the based of the petals

Leaves generally consist of

a flattened blade and a stalk called the petiole, which joins the leaf to a node of the stem

seed

a structure that includes an embryo and a store of nutrients provided by the mother surrounded by a tough, protective coat

Fruit

a structure that is derived from the ovary and encloses one or more seeds

root hairs

absorption of water and minerals increase the surface area

The vascular cambium

adds layers of vascular tissue called secondary xylem (wood) and secondary phloem

Angiosperm Radiation

allow angiosperms to transport water, pollen, and seeds efficiently

Where are vessel elements found?

angiosperms and a few gymnosperms -Vessel elements align end to end to form long micropipes -Water travels between vessels through perforation plates

Sieve plates

are the porous end walls that allow fluid to flow between cells along the sieve tube

•The vascular tissue of most angiosperms contains

both tracheids and vessel elements

Seeds are dispersed by what

by wind, water, or animals

vascular tissue system

carries out long-distance transport of materials between roots and shoots

Where do microsporangia and megasporangia develop?

cones

Bark

consists of all the tissues external to the vascular cambium, including secondary phloem and periderm

microsporangia

contain a cell that divides by meiosis to form microspores, which then divide by mitosis to form pollen grains—tiny male gametophytes

Megasporangia

contain a mother cell that divides by meiosis to form a megaspore, which undergoes mitosis to form the female gametophyte, which contains egg cells

The stamen

contains the anther, where microsporangia develop

The carpel

contains the ovary in which the ovules are found -Ovules contain the megasporangia

What were key adaptions that allowed early plants to colonize

cuticle, stomata, and vascular tissue

Each plant organ has

dermal, vascular, and ground tissues

Fruits

develop from the flower's seed-producing organ and contain seeds

How are angiosperms different from gymnosperms in Heterospory

double fertilization

Apical meristemsterm-82

elongate shoots and roots, a process called primary growth

Meristems do what

generate cells for new organs

Cork Cambium

gives rise to the secondary plant body's protective covering, or periderm -Periderm consists of the cork cambium plus the layers of cork cells it produces

Apical dominance

helps to maintain dormancy in most nonapical buds

What happened when pollen evolved?

heterosporous plants lost their dependence on water for fertilization

Lenticels

in the periderm allow for gas exchange between living stem or root cells and outside air

"double dormancy"

in which they need both scarification and stratification

apical bud [terminal bud]

is located near the shoot tip and causes elongation of a young shoot

Stamens and carpels later became enclosed

modified leaves called sepals and petals -The four structures then diversified to produce a fantastic array of sizes, shapes, and colors -Specialized cells inside flowers also began producing a wide range of scents

angiosperms have traditionally been divided into the two major groups

monocotyledons (monocots) and the dicotyledons (dicots) -The groups are divided based on differences in their cotyledons, or first leaves

companion cell

nucleus and ribosomes serve both cells

Petals

often brightly colored and advertise the flower to pollinators. The entire group of petals in a flower is called the corolla.

Where are Megasporangia found?

ovules

In woody plants

primary and secondary growth occur simultaneously but in different locations

carpel

produces the female gametophytes, which produce eggs.

roots

rely on sugar produced by photosynthesis in the shoot system

shoots

rely on water and minerals absorbed by the root system

Stamens

reproductive structures that produce male gametophytes (pollen grains), which in turn produce sperm.

Three different plant organs

roots, stems, and leaves

Angiosperms

seed plants that have vasculature that includes both tracheids and vessel elements Angiosperms also have seeds that develop inside vessels ("angio" means vessel) and ovaries that develop into fruits

Ferns and their allies:

seedless vascular plants and the sporophyte stage is dominant

Green Algae

single-celled Any body of water will have Algae in it

Flowers contain two key reproductive structures

stamens and carpels

Female gametophyte

stays attached to the sporophyte as pollen grains arrive and produce sperm that fertilize the eggs

leaf

the main photosynthetic organ of most vascular plants

Pollen grains

the microspore germinates to form a tiny male gametophyte that is surrounded by a tough coat of sporopollenin

Seeds allow embryos

to be dispersed to a new habitat, away from the parent plant

two types of water-conducting cells

tracheids and vessel elements, are dead at maturity

•Sieve-tube elements

transport nutrients and are alive at functional maturity, though they lack organelles •Sieve plates are the porous end walls that allow fluid to flow between cells along

two lateral meristems

vascular cambium and cork cambium

initials

which remain in the meristem and give rise to new cells, and other cells called derivatives, which become specialized in developing tissues

Where are tracheids found?

xylem of all vascular plants •Water moves from cell to cell through pits

Anthophyta (Angiosperms)

•Angiosperms have ovules, which develop into seeds -Ovules are surrounded by ovaries, which develop into fruit •In most terrestrial habitats today, angiosperms supply the food that supports virtually every other species, including humans

Traits of Fruit

•Fruits are mature ovaries that ripen when pollinated •Fruits can be fleshy or dry •Fruits protect seeds and aid in dispersal

Ground tissue system

•Ground tissue internal to the vascular tissue is pith; ground tissue external to the vascular tissue is cortex •Ground tissue includes cells specialized for storage, photosynthesis, and support

Dermal tissue system

•In nonwoody plants, the dermal tissue system consists of the epidermis •A waxy coating called the cuticle helps prevent water loss from the epidermis •In woody plants, protective tissues called periderm replace the epidermis in older regions of stems and roots -Trichomes are outgrowths of the shoot epidermis and can help with insect defense

Differences between Monocots and Eudicots

•Monocots have one cotyledon, the first leaf, while dicots have two •Monocots have scattered vascular tissue throughout the stem while the vascular tissue is arranged in a circle in dicot stems •Monocot leaves have parallel veins while dicot leaves have branching veins •Monocot flower petals are in multiples of three while the petals of dicot flowers are in multiples of four or five

Pinophyta

•Pines have a unique arrangement of needle-like leaves. •Their seeds are important food items for many birds and small mammals. •Their wood is the basis of building and paper products.

Secondary Growth

•Secondary growth occurs in roots and stems but rarely in leaves •Secondary growth is characteristic of gymnosperms and many eudicots, but not monocots

Common information on wood

•Secondary xylem accumulates as wood, and consists of tracheids, vessel elements (only in angiosperms), and fibers •Early wood, formed in the spring, has thin cell walls to maximize water delivery •Late wood, formed in late summer, has thick-walled cells and contributes more to stem support •Tree rings are visible where late and early wood meet, and can be used to estimate a tree's age •As a tree or woody shrub ages, the older layers of secondary xylem, the heartwood, no longer transport water and minerals •The outer layers, known as sapwood, still transport materials through the xylem •Older secondary phloem sloughs off and does not accumulate

advantage and disadvantage of asexual reproduction

•The advantage of asexual reproduction is that it is very efficient •The major disadvantage is that genetically similar populations are more likely to succumb to diseases

Phylum Anthophyta

•The angiosperms are the most species-rich of the land plants, with over 250,000 known species •They are the most common and abundant plants in most terrestrial environments. •The defining adaptation of angiosperms is the flower.

Seed Plants

•The seed plants are a monophyletic group that consists of the gymnosperms and the angiosperms •They are defined by the production of seeds and pollen grains •They are found in virtually every type of habitat, and they adopt every growth habit known in land plants •Seed plants are all heterosporous

Common information on Vascular Cambrium

•The vascular cambium is a cylinder of meristematic cells one cell layer thick •It develops from undifferentiated parenchyma cells •In cross section, the vascular cambium appears as a ring of initials •The initials increase the vascular cambium's circumference and add secondary xylem to the inside and secondary phloem to the outside

General Facts about fruit

•Tissues derived from the ovary are often nutritious and brightly colored •Whereas the evolution of flowers made efficient pollination possible, the evolution of fruit made efficient seed dispersal possible

Seed Dispersal

•Wind, water, or animals can carry them to new locations, enhancing dispersal •Other methods -Ballistic -Water -Animal feet/legs

flowers

•a reproductive structure that produces gametes, attracts gametes from other individuals, nourishes embryos, and develops seeds and fruits.

Sepals

•are leaflike structures that make up the outermost part of the flower. They are usually green and photosynthetic. •They are arranged in a circle or whorl attached to the receptacle and enclose the flower bud as it develops and grows. •The entire group of sepals in the flower is called the calyx.

Sclerenchyma cells

•are rigid because of thick secondary walls strengthened with lignin •They are dead at functional maturity

asexual reproduction

•does not involve fertilization and results in the production of clones―genetically identical copies of the parent plant -Sprouting -Layering -Fragmentation

All seeds need

•light, water, an optimum temperature, and oxygen to germinate

cork cambium

•replaces the epidermis with periderm, which is thicker and tougher