Seed Plants Seed Plants

Gymnosperms & AngiospermsGymnosperms & Angiosperms

What is a seed??What is a seed??

A seed contains an embryonic sporophyteA seed contains an embryonic sporophyte It has a protective coat and enough nutrients to It has a protective coat and enough nutrients to

support the sporophyte until it is ready to support the sporophyte until it is ready to germinategerminate

Seeds differ depending on their mode of Seeds differ depending on their mode of species dispersal …eg: wind, animals, water species dispersal …eg: wind, animals, water etc.etc.

Gymnosperm = “Naked Seeds”Gymnosperm = “Naked Seeds”

In gymnosperms the In gymnosperms the seeds are uncovered or seeds are uncovered or “naked”“naked”

They are often exposed They are often exposed on the surface of scales on the surface of scales in conesin cones

Angiosperm SeedsAngiosperm Seeds

In angiosperms, the In angiosperms, the seeds are covered by seeds are covered by fruitfruit

Seed Plant Life CycleSeed Plant Life Cycle

A seed germinates into a sporophyteA seed germinates into a sporophyte The sporophyte produces megaspores and The sporophyte produces megaspores and

microspores by meiosismicrospores by meiosis The spores develop into megagametophytes The spores develop into megagametophytes

and microgametophytesand microgametophytes Fertilization takes placeFertilization takes place A seed is formedA seed is formed

Two Types of GametesTwo Types of Gametes

MicrosporesMicrospores develops into a develops into a

microgametophyte microgametophyte In seed plants this is the In seed plants this is the

POLLEN grainPOLLEN grain

MegasporesMegaspores Develops into a Develops into a

megagametophytemegagametophyte In seed plants this is the In seed plants this is the

EMBRYO sacEMBRYO sac

General Life Cycle…General Life Cycle…

In Gymnosperms….In Gymnosperms….

In Angiosperms…In Angiosperms…

GymnospermsGymnosperms

Includes Cycads, Gingko and ConifersIncludes Cycads, Gingko and Conifers

Gymnosperm Adaptations to Gymnosperm Adaptations to Land…Land…

SeedsSeeds allow for species dispersal on land allow for species dispersal on land NeedlesNeedles maintain water balance in dry cold maintain water balance in dry cold

climatesclimates Vascular tissueVascular tissue transports nutrients and transports nutrients and

water from surroundings throughout the plantwater from surroundings throughout the plant Pollen Pollen can be transported by wind, animals can be transported by wind, animals

or insects for fertilization or insects for fertilization

AngiospermsAngiosperms

An exceptionally large and successful group of An exceptionally large and successful group of plantsplants

Includes:Includes: All deciduous treesAll deciduous trees All broad leafed evergreen treesAll broad leafed evergreen trees All non-woody plants such as grasses, garden All non-woody plants such as grasses, garden

plants, flowering plantsplants, flowering plants

Some examples of angiosperms…Some examples of angiosperms…

Two Groups of Angiosperms..Two Groups of Angiosperms..Monocotyldons & DicotyldonsMonocotyldons & Dicotyldons

Flower StructureFlower Structure Heterospores (microspores & megaspores) are produced Heterospores (microspores & megaspores) are produced

within flowerswithin flowers SepalSepal

green, beneath the petals, protect the developing flowergreen, beneath the petals, protect the developing flower PetalsPetals

attract pollinatorsattract pollinators PistilPistil

vaselike structure in the centre of the flower, has 3 parts; stigma, style vaselike structure in the centre of the flower, has 3 parts; stigma, style & ovary& ovary

Stigma is an enlarged, sticky knob at the top of the pistil (sticks to pollen)Stigma is an enlarged, sticky knob at the top of the pistil (sticks to pollen) Style is the stalk between the stigma and the ovaryStyle is the stalk between the stigma and the ovary Ovary is the enlarged base containing ovulesOvary is the enlarged base containing ovules

StamensStamens grouped around the pistil, has 2 parts; the filament and the anthergrouped around the pistil, has 2 parts; the filament and the anther

Anther has 2 pollen sacsAnther has 2 pollen sacs Filament attaches the pollen sac to the flowerFilament attaches the pollen sac to the flower

Plant ReproductionPlant Reproduction

Pollen is produced by the stamenPollen is produced by the stamen Pollen moves away from the plant by wind or Pollen moves away from the plant by wind or

pollinatorspollinators The pollen lands on the pistil of another flower The pollen lands on the pistil of another flower

and fertilizes the eggs within the ovaryand fertilizes the eggs within the ovary The flower petal falls off and the ovary The flower petal falls off and the ovary

develops into a fruit that encloses the seedsdevelops into a fruit that encloses the seeds Fruits are dispersed in a variety of waysFruits are dispersed in a variety of ways EgEgeaten by animals, acorns, dandelions etc.eaten by animals, acorns, dandelions etc.

Flower StructureFlower Structure

AssignmentAssignment Prepare a summary chart comparing angiosperms and Prepare a summary chart comparing angiosperms and

gymnospermsgymnosperms

GymnospermGymnosperm AngiospermsAngiosperms

General General Characteristics Characteristics

Life Cycle and Life Cycle and Reproductive Reproductive StructuresStructures

Adaptations & Adaptations & Unique Unique CharacteristicsCharacteristics

Examples & Examples & ClassificationClassification