GYMNOSPERMS

 

-         phlya Ginkgophyta, Gnetophyta, Cycadophyta and Coniferophyta

-         vascular plants with true roots

-         gymnosperms = “naked seeds”

-         cones/strobili

-         have seeds that develop on the surfaces of sporophylls instead of in ovaries like angiosperms

-         microsporangium produces pollen grains (sperm) and the megasporangium produces the egg

-         sporophyte generation is dominant

-         no water needed for fertilization – pollen travels with the wind

 

Pine trees

-         monoecious (separate male and female cones on the same plant)

-         have needle-shaped leaves that adapt the tree to dry conditions

-         produce cones – male and female

-         male cones produce microsporangia (pollen sacs) that produce microspores (4) which mature into pollen grains (microgametophyte) with wings for wind dispersal

-         female megasporocytes within the ovule undergo meiosis early producing megaspores (4) of which three degenerate and one is functional – this one undergoes mitosis to produce the female gametophyte (megagametophyte) = egg which lies in the archegonium

-         Fertilization – pollen sticks to female scales to a drop of fluid which  evaporates moving the pollen closer to the megasporangium and then the scales close.  Pollen tube then grows down into female gametophyte and the pollen divides into 2 sperm – one fertilizes the egg to produce a zygote and the other disintegrates.

-         Seed coat then surrounds embryo and wings develop for dispersal

 

Pine Life Cycle:

(Vodopich and Moore, pg 307)

 

Leaves arranged in bundles (fascicles)

http://www.science.siu.edu/landplants/Coniferophyta/images/Pine.needles.JPEG

Female (Ovulate) Cones

http://www.science.siu.edu/landplants/Coniferophyta/images/Pinus.cones.JPEG

 

Immature female cones (winter)

 

http://www.science.siu.edu/landplants/Coniferophyta/images/Pinus.yng.cone.JPEG

 

Male (Staminate) cones

http://web.gccaz.edu/~lsola/NonFlwr/PineM.jpg

 

                             

 

Cycads

 

- woody plants that produce seeds

- resemble palms

- dioecous

- male and female cones

- insect pollinated

- Zamia genus in the US

- variation in trunk length

- life cycle similar to other gymnosperms

 

Zamia Male strobilus

 

 

http://www.science.siu.edu/landplants/Cycadophyta/images/Zamia.cone.JPEG

 

Zamia Female Stobili

 

 

http://www.science.siu.edu/landplants/Cycadophyta/images/Zamia.pum.cone.JPEG

 

 

 

ANGIOSPERMS

 

-          flowering plants

-         angiosperm = seeds in a fruit

-          vascular seed plants

-          produce reproductive structures - flowers and fruits

-         differ from gymnosperms in that they produce seeds which are enclosed in ovaries as they develop

 

Text Box: lilies, orchids, grasses (corn, wheat) and palms
 

Text Box: roses, peas, sunflowers, oaks and maples 
 

 

 

 

http://trc.ucdavis.edu/biosci10v/bis10v/week8/dicotmonocot.gif

 

 

 

-     sporophyte generation dominates the life cycle

-         ovary develops into a fruit

-         ovules develop into seeds

-         flower produces microspores that are contained within pollen grains and the egg develops within the ovules

-         Fertilization (double) involves the release of pollen that sticks to the stigma and then a pollen tube grows down the style toward the ovules releasing 2 sperm

-         1 of the sperm fertilizes the egg to forming a diploid zygote (2n) which will develop into a seed

-         the second sperm unites with the large center cell (polar nuclei) of the female gametophye resulting in a triploid (3n) cell which develops into the endosperm (surrounds the embryo and provides nutrition for the seed until it can photosynthesize on its own)

 

Life cycle of a typical angiosperm

 

 

 

http://trc.ucdavis.edu/biosci10v/bis10v/week8/dicotmonocot.gif

 

FLOWERS:

 

 

 

http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20Laboratory/Seed%20Plants/Lily_flower.jpg

 

 

Sepals

      - protect developing bud

 

 

Petals (corolla)

      - function to attract pollinators

 

 

Stamens

      - anther and filament

      - microspores and microgametophytes are produced within the anther.

 

Ovules

      - will become seeds

      - contain megasporangium within which the megaspores are produced by meiosis

      - the megaspores produce megagametophytes, which, in turn, produce eggs

 

 

Carpel/Pistil

      - the stigma, style, and ovary

 

 

Ovary

      - the bottom portion of a pistil

      - contains ovules

      - enlarges and becomes the fruit and the ovules become seeds

 

 

Peduncle

      - flower stalk

 

 

Androecium

 

      - male parts of the plant

 

 

Gynoecium

 

      - female parts of the plant

 

 

 

Plants: Reproduction

 

A) Flowers
 

 

http://www.northernontarioflora.ca/images/flower_term1.jpg

 

 

 

Flower Type/Ovary Position:

 

Text Box: Ovary is superior; sepals, petals and stamens are inferior to the ovary

Text Box: Floral parts fuse halfway to the ovary

Text Box: Ovary is inferior; sepals, petals and stamens are on top of the ovary

 

                                     http://www.puc.edu/Faculty/Gilbert_Muth/art0021.jpg

 

 

 

Flower Symmetry:

 

 

           Radial (Actinomorphic)                               

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

              Bilateral (Zygomorphic)

 

 

http://images.google.com/imgres?imgurl=http://www.museums.org.za/bio/

images/enb5/enb05064_actino.jpg&imgrefurl=http://www.museums.org.za/bio/glossary/bio/actinomorphic_

zygomorphic.htm&h=300&w=300&sz=15&hl=en&start=10&tbnid=beVBe2Wf2FWQVM:&tbnh=116&tbnw=

116&prev=/images%3Fq%3DActinomorphic%26gbv%3D2%26ndsp%3D20%26svnum%3D10%26hl%3Den%26sa%3DN

 

 

 

 

Pollination

 

  1. Wind

 

  1. Insect

 

 

Flower Pollination and Fertilization:

 

 

 

-    4 microsporangia in each anther

-         each microsporangia produce microspore mother cells that undergo meiosis to produce 4 pollen grains per microsporocyte

 

http://images.iasprr.org/lily/tetrad.jpg

 

 

-         microsporocytes fall apart and the microspores are released

-         each microspore divides and produces a pollen vegetative and a generative cell

-         generative cell divides again to produce 2 sperm

 

 

undefined

http://www.iwebquest.com/pollinate/images/Pollen.jpg

 

 

 

-         double fertilization in the ovary – zygote and an endosperm

 

 

Life Cycle of the Flower:

 

(Vodopich and Moore, pg 316)

 

 

-         ovary develops into a fruit and ovules develop into seeds

-         flower produces microspores that are contained within pollen grains and the egg develops within the ovules

-         Fertilization (double) involves the release of pollen that sticks to the stigma and then a pollen tube grows down the style toward the ovules releasing 2 sperm

-         1 of the sperm fertilizes the egg to forming a diploid zygote (2n) which will develop into a seed

-         the second sperm unites with the large center cell (polar nuclei) of the female gametophye resulting in a triploid (3n) cell which develops into the endosperm (surrounds the embryo and provides nutrition for the seed until it can photosynthesize on its own)

-

 

 

B) Seeds

- mature ovule

- three main parts:

 

 

(Vodopich and Moore, pg 341)

            Proembryo stage

-         zygote divides to form a mass of cells = embryo

-         embryo consists of a basal cell, suspensor, and a two-celled proembryo

-         suspensor is the column of cells that pushes the embryo into the endosperm

         Globular stage

-         Cell division of the proembryo leads to the globular stage

-         radially symmetrical

-         little internal cellular organization

 

         Heart-shaped stage

-         Division of the globular stage produces bilateral symmetry and two cotyledons

-         cotyledons store digested food from the endosperm

-         tissue differentiation begins

-         root and shoot meristems appear

 

         Torpedo stage

-         cotyledons elongate

-         precambial tissue appears (develops into vascular tissue)

 

         Mature embryo

-         has large bent cotyledons on either side of the stem apical meristem

-         radicle (forms root) has a root apical meristem and a root cap (as root pushes through the soil, the outer (older) cells of the root cap are sloughed off and replaced by new cells from the root apical meristem)

-         hypocotol = region between apical meristem and radicle

-         endosperm is depleted and food is stored in the cotyledons

-         epicotyl = region between the attachment of cotyledons and stem apical meristem

 

                                                Mature Embryo – Torpedo Stage

 

Capsella embryo

http://images.google.com/imgres?imgurl=http://www.uri.edu/cels/bio/plant_anatomy/images/THUMB22.GIF&imgrefurl=http://

www.uri.edu/cels/bio/plant_anatomy/thumbnails.html&h=63&w=96&sz=5&hl=en&start=49&tbnid=JiFqtVnpuR-tYM:&tbnh=53&tbnw=81&prev=/images%3Fq%3Dmature%2Bembryo%26start%3D40%26gbv%3D2%26ndsp%3

D20%26svnum%3D10%26hl%3Den%26sa%3DN

 

Monocot and Dicot Seeds:

        http://biology.unm.edu/ccouncil/Biology_203/Images/FloweringPlants/seedgermmonodi.gif

 

 

(Vodopich and Moore, pg 342)

 

 

C) Fruits:

 

-         ripened ovaries

-         ovary wall develops into fruit wall from the carpels (one or many)

-         ovules develop into seeds

-         “true fruits”

-         “false fruits”

-         berries = aggregate fruits, dry fruits at maturity and then breaks open - fruit = capsule

-         ovary wall can develop into a fruit of different layers, including an inner one that is stony—a drupe (like a peach) 

-         when the ovaries of separate flowers fuse together to they form a compound or multiple fruit, such as a pineapple 

-         parthenocarpy = absence of seeds

-         possible to examine a fruit to determine the ovary’s position in the flower

                  - if scars or parts of old petal and sepals are at the tip of the fruit, the

                    flower was inferior (apple) and if at the base then superior (orange) 

 

 

Parts:

  

http://academic.kellogg.cc.mi.us/herbrandsonc/bio111/images/stems/seeds_4.jpg

 

 A) Pericarp - external part of a fruit which surrounds the seed

 

1.      exocarp

2.      mericarp

3.      endocarp

B) Seed

 

è Fleshy Fruits

 

      Simple fruits

                  - from a single ovary

 

                  - flesh mostly of ovary tissue

                               a) endocarp hard and stony; ovary superior and single-seeded                                          (cherry, olive, coconut): drupe

                              b) endocarp fleshy or slimy; ovary usually many seeded (tomato,                                                   grape, green pepper): berry

 

                  - flesh mostly of receptacle tissue (apple, pear, quince): pome

 

 

          Complex fruits

                  - from more that 1 ovary

                              a) fruit from many carpels on a single flower (strawberry, raspberry): aggregate fruit

                              b) fruit from carpels of many flowers fused together (pineapple): multiple fruit

 

è Dry Fruits

 

                  - fruits that split open at maturity (usually more than one seed)

                              a) split occurs along two seems in the ovary.  Seeds borne on one

                                  of the halves of the split ovary (pea and bean pods, peanuts): legume

                              b) seeds released through pores or multiple seams (poppies, irises, lilies): capsule

 

                  - fruits that do not split open at maturity (usually one seed)

                              a) pericarps hard and thick, with a cup at its base (acorn, chestnut): nut

                              b) pericarp thin and winged (maple, ash, elm): samara

                              c) pericarp this and not winged (sunflower, buttercup): achene (cereal grains): caryopsis

 

 

D) Stems:

 

-         holds up leaves – important for photosynthesis

-         holds up flowers for pollination

-         xylem carries water and minerals up from roots to the leaves

-         phloem takes food back down to be stored and distributed as needed

-         herbaceous – green, flexible and has notches where leaves develop

-         woody -  covered by bark, have scars where twigs and fruit have dropped off and have small openings for transpiration

-         primary growth occurs from the apical meristems of shoots and roots è apical growth

-         secondary growth – increase in girth (diameter) of stems and roots (especially woody plants) è lateral growth

           

 

 

            Woody Stems:

 

 

(Vodopich and Moore, pg 333)

Text Box: pith

 

 

 

http://www.ri.net/schools/Narragansett/NHS/PerDwebpage/woodystem.GIF

 

 

 

Leaves:

 

-         leaf structure have been optimized for photosynthesis

o       a flat surface for maximum exposure to sunlight

                  chloroplasts are concentrated on upper surface to receive maximum exposure to sunlight

·        stomata regulate the entry of CO2 into the leaf and air spaces inside the leaf permit rapid diffusion

·        water is pulled into the leaf from the roots by transpiration, the evaporative loss of water from leaf surfaces

 

           Parts:

 

-         expanded, photosynthetic portion of the leaf = a blade/lamina.

-         between lamina and stem there may or may not be a stalk = petiole

-         all leaves have a bud where they attach to the stem - a bud defines a leaf, no matter what type of leaf it is

-         no apical meristem therefore that are determinate – limited growth

 

 

Complexity:

 

-         simple or compound

-         simple if a leaf has one lamina

-         compound if it has more than one lamina (individual laminas = leaflets

 

 

Venation:

 

-         if all the leaflets arise from the same point on the petiole, the leaf  = palmate

-         if the leaflets occur in pairs along the central stalk, the leaf = pinnate

 

 

            Arrangement:

 

-         the arrangement of leaves on a stem = phyllotaxy

-         Leaves may be arranged in three ways:

·        alternate - 1 leaf per node

·        opposite - 2 leaves per node

·        whorled - 3 or more leaves per node

 

 

 

http://www2.medford.k12.wi.us:8400/~swedltr/Course%20Pages/BiologyCourse_files/leafcollectioninstructions2006_files/image004.jpg

 

 

 

 

 

 

http://www.ncnhdistrict.org/images/leafstructure.jpg

 

 

 

 

Anatomy:

 

1.      Epidermis

 

-         outer layer of cells

-         upper and lower epidermis

-         covered by a cuticle, a waxy or fatty layer, that functions to reduce water loss

-         usually only one cell thick

-         stomata = specialized epidermal structures

·        consist of a pair of guard cells that form a pore for gas exchange

·        open and close in response to environmental clues

·        may occur on both leaf surfaces, but are more numerous on the lower surface

 

 

http://www.puc.edu/Faculty/Gilbert_Muth/art0077.jpg

 

 

 

2.      Mesophyll

 

-         mesophyll = "middle leaf"

-         ground tissue of the leaf

-         contains air spaces for the diffusion of gases

-         chloroplasts for photosynthesis

-         2 layers in dicots:

 

·        Palisade mesophyll

·        cells = chlorenchyma (parenchyma cells with chlorophyll) and are tightly packed, columnar cells

·        photosynthetic activity takes place here therefore, there are more chloroplasts than in the spongy layer

 

·        Spongy mesophyll

·        Cells = parenchyma and are irregularly shaped and less compact – appear "spongy"

·        photosynthetic activity is lower than in the palisade layer

 

 

3.      Vascular bundles

 

-         xylem towards the upper surface of leaf

-         phloem towards lower surface of leaf

-         vascular tissues of veins are enclosed by parenchyma cells or compactly arranged bundle sheath cells

                  - ensures that the vascular system is not exposed to the air and that

                     all substances entering and leaving the vascular tissues must pass

                     through the sheath

-         veins of dicots are usually bordered by collenchyma or sclerenchyma for strength