11.3 Seeds and Pollen11.3 Seeds and Pollen

Seeds and pollen are plant Seeds and pollen are plant adaptations.adaptations.

11.3 Seeds11.3 Seeds

A A seedseed is a young plant that is enclosed in a is a young plant that is enclosed in a protective coating. protective coating.

Within the coating are enough nutrients to Within the coating are enough nutrients to enable the plant to grow.enable the plant to grow.

Seeds and spores can both withstand harsh Seeds and spores can both withstand harsh conditions.conditions.

Seeds plants have an advantage over seedless Seeds plants have an advantage over seedless plantsplants

11.3 Seeds11.3 Seeds

In all plants, fertilization brings about the growth of In all plants, fertilization brings about the growth of the next generation of the plant.the next generation of the plant.

Embryo Embryo = the immature form of an organism that has = the immature form of an organism that has the potential to grow and develop the potential to grow and develop

The The seed coatseed coat protects the immature plant until protects the immature plant until conditions (moisture, temp, etc.) are right for growth.conditions (moisture, temp, etc.) are right for growth.

GerminationGermination = beginning of growth of a new plant = beginning of growth of a new plant from a spore or seed. (sprouting!)from a spore or seed. (sprouting!)

Uses stored energy in seed until roots/shoots can Uses stored energy in seed until roots/shoots can function.function.

11.3 Seed bearing plants11.3 Seed bearing plants

Trees, bushes, flowers, and grasses are all seed Trees, bushes, flowers, and grasses are all seed plants.plants.

SeedsSeeds vsvs SporesSpores Multicellular embryoMulticellular embryo single cellsingle cell Have nuturient supplyHave nuturient supply no nutrient supplyno nutrient supply

Both: protective coating, can survive harsh Both: protective coating, can survive harsh conditions, contain parent DNAconditions, contain parent DNA

11.3 How Seeds Spread11.3 How Seeds Spread

SporesSpores Wind Wind

SeedsSeeds WindWind WaterWater AnimalsAnimals PoppingPopping

Inside a seedInside a seed

Seed Coat

Stored Nutrients

Seed

Embryo

11.3 Pine Trees11.3 Pine Trees

PollenPollen = small multicellular structure that holds a = small multicellular structure that holds a sperm cell (non-swimming plant sperm) sperm cell (non-swimming plant sperm)

Carried by: wind, water, animals (bugs/birds)Carried by: wind, water, animals (bugs/birds) Pinecone = reproductive structure of pine treePinecone = reproductive structure of pine tree Meiosis occurs in cones which produce sperm and egg Meiosis occurs in cones which produce sperm and egg

cells in separate mail & female conescells in separate mail & female cones Pollen is in male cones; Eggs in female cones (Gen1)Pollen is in male cones; Eggs in female cones (Gen1) Cone produces a sticky substance which “catches” the Cone produces a sticky substance which “catches” the

male pollen which grows a pollen tube . When pollen male pollen which grows a pollen tube . When pollen gets to egg, fertilization occurs and embryo grows.gets to egg, fertilization occurs and embryo grows.

Seeds are released & Sprout (Gen.2)Seeds are released & Sprout (Gen.2)

11.3 Gymnosperms11.3 Gymnosperms

Gymnosperms are Gymnosperms are

seed plants w/o fruitseed plants w/o fruitThere are 4 typesThere are 4 types

11.3 Gymnosperms11.3 Gymnosperms

Pollen and seeds are reproductive adaptations Pollen and seeds are reproductive adaptations that did not appear for millions of years after that did not appear for millions of years after mosses & ferns.mosses & ferns.

Today, most plants on earth reproduce with Today, most plants on earth reproduce with seeds (gymnosperms) & many seedless seeds (gymnosperms) & many seedless plants are extinct.plants are extinct.

Fossils prove gymnosperm “naked seed” Fossils prove gymnosperm “naked seed” plants are more than 250 million years old.plants are more than 250 million years old.

11.3 Conifers11.3 Conifers

Cone bearing trees = pine, fir, spruce, Cone bearing trees = pine, fir, spruce, hemlock, cypress, and redwood treeshemlock, cypress, and redwood trees

Live in cold climates with limited waterLive in cold climates with limited water Leaves are thick, needle-shaped, & have a Leaves are thick, needle-shaped, & have a

thick cuticlethick cuticle Keep needles for several years & therefore can Keep needles for several years & therefore can

produce sugar all year so some are called produce sugar all year so some are called “evergreens”“evergreens”

11.3 11.3 Other gymnospermsOther gymnosperms

Cycads – tropical, cone producing, palm-like Cycads – tropical, cone producing, palm-like plants; many produce poisonous compoundsplants; many produce poisonous compounds

Gnetophytes – tropical, cone producing, Gnetophytes – tropical, cone producing, chemicals from them have been used to treat chemicals from them have been used to treat coldscolds

Ginkgoes – have fleshy seeds that hang down. Ginkgoes – have fleshy seeds that hang down. Male seed coats smell bad. Male seed coats smell bad.