Plant ReproductionPlant Reproduction

A Quick ReviewA Quick Review

Plants Plants alternate generationsalternate generations..

- - GametophyteGametophyte - - haploidhaploid plant which plant which produces produces gametesgametes

- - gametesgametes - - haploidhaploid cells which cells which fuse fuse and develop into and develop into sporophytesporophyte

Fern Gametophyte Pollen – Male gametophyte

- - SporophyteSporophyte - - diploiddiploid plant which plant which produces produces sporesspores

- - sporesspores - - haploidhaploid cells which cells which develop into develop into gametophytegametophyte

Plants Plants alternate generationsalternate generations..

Fern Sporophyte Spider-plant Sporophyte

alternation of generationsalternation of generations

B. B. Development of Development of pollen and seedspollen and seeds led to the evolution of Seed Plantsled to the evolution of Seed Plants..

- - MaleMale gametophyte develops as the gametophyte develops as the pollenpollen grain grain

- - FemaleFemale gametophyte develops inside gametophyte develops inside ovulesovules

- eggs develop into - eggs develop into seedseed, a , a packaged packaged embryo with food supply & protective coaembryo with food supply & protective coatt

Pumpkin SeedsPollenSunflower Seeds

Plant ReproductionPlant ReproductionSexual Reproduction of Sexual Reproduction of

Seed PlantsSeed Plants

A.A. Gymnosperms (naked-seed)Gymnosperms (naked-seed)- - Gnetophytes, Cycads, Ginkgos, and ConifersGnetophytes, Cycads, Ginkgos, and Conifers

1. Reproduction 1. Reproduction in in Pollen ConesPollen Cones & & Seed ConesSeed Cones

- have - have “naked” seeds“naked” seeds, or seeds that are not , or seeds that are not covered, inside of covered, inside of conescones

Wollemi PineRed – Pollen ConesGreen – Seed cones

Black AdlerBrown – Pollen Cones

Black – Seed cones

- Small - Small male conesmale cones produce produce pollenpollen

((male gametophytemale gametophyte))

- Larger - Larger female conesfemale cones produce produce ovulesovules

((female gametophyte female gametophyte develops)develops)

A.A. Gymnosperms (naked-seed)Gymnosperms (naked-seed)- - Gnetophytes, Cycads, Ginkgos, and ConifersGnetophytes, Cycads, Ginkgos, and Conifers

Female Cone

Male Cone

2. 2. PollinationPollination - By - By windwind; ; pollen is blown pollen is blown on to female coneson to female cones

A.A. Gymnosperms Gymnosperms - - Gnetophytes, Cycads, Ginkgos, and ConifersGnetophytes, Cycads, Ginkgos, and Conifers

3.3. Fertilization - Pollen grows pollen tube Fertilization - Pollen grows pollen tube and takes 2 haploid sperm into ovuleand takes 2 haploid sperm into ovule

- 1 sperm - 1 sperm fertilizes the eggfertilizes the egg

- the other sperm is - the other sperm is discardeddiscarded

4. Seed Development - Egg develops into 4. Seed Development - Egg develops into a zygote (a zygote (the new sporophytethe new sporophyte) within ) within the seedthe seed

A.A. Gymnosperms (naked-seed)Gymnosperms (naked-seed)- - Gnetophytes, Cycads, Ginkgos, and ConifersGnetophytes, Cycads, Ginkgos, and Conifers

B. Angiosperms (covered-seed) B. Angiosperms (covered-seed) - all flowering plants- all flowering plants

1. 1. ReproductioReproduction takes place in n takes place in flowersflowers

- Have - Have covered seeds found inside a covered seeds found inside a fruitfruit that develops from a that develops from a flowerflower

Titan Arum Biggest Flower

Strawberry – only fruit with outside seeds!

Orchid Smallest Seed

B. Angiosperms (covered-seed)B. Angiosperms (covered-seed)- all flowering plants- all flowering plants

- FlowerFlower is composed of 4 specialized is composed of 4 specialized leaves leaves

1. 1. SepalsSepals - - covers developing flowercovers developing flower, , sterilesterile

2. 2. PetalsPetals - often - often brightly colored,brightly colored, sterilesterile

3. 3. Carpel/PistilCarpel/Pistil - - FemaleFemale reproductivereproductive structures structures

4. 4. StamenStamen - - Male reproductiveMale reproductive structures structures

Lily Foxglove Hibiscus

Lily Rose

B. Angiosperms B. Angiosperms - all flowering plants- all flowering plants

3. Carpel/Pistil - 3. Carpel/Pistil - Female reproductive structuresFemale reproductive structures

a.a. Stigma - sticky, Stigma - sticky, receives pollenreceives pollen

b.b. Style - stalk which Style - stalk which holds stigma upholds stigma up

c.c. Ovary - Ovary - contains one or more ovulescontains one or more ovules

B. Angiosperms B. Angiosperms - all flowering plants- all flowering plants

4. Stamen - Male reproductive structures4. Stamen - Male reproductive structures

a. Filament - a. Filament - holds anther upholds anther up

b. Anther - b. Anther - produces pollenproduces pollen

B. Angiosperms B. Angiosperms (board) (board)

Female vs. MaleFemale vs. Male

B. Angiosperms B. Angiosperms - all flowering plants- all flowering plants

2. Pollination - most flowers are pollinated by 2. Pollination - most flowers are pollinated by animals, some by windanimals, some by wind

- the shape, color, and scent of the flower - the shape, color, and scent of the flower can tell us what animal pollinates themcan tell us what animal pollinates them

Birds – Red/Hanging Flowers Insects – can see UV light!

Smells Like…Smells Like…

Starfish Flower

The Wasp and Fig Story!The Wasp and Fig Story!

B. Angiosperms B. Angiosperms - all flowering plants- all flowering plants

3. Fertilization - Pollen grows pollen tube and 3. Fertilization - Pollen grows pollen tube and takes 2 haploid sperm into ovuletakes 2 haploid sperm into ovule

a. Double fertilization occursa. Double fertilization occurs

- one sperm - one sperm fertilizes the eggfertilizes the egg

- one sperm - one sperm fertilizes the fertilizes the endosperm, endosperm, or or nourishment for developing nourishment for developing seedlingseedling

Pollen Tube

Pollen Tube

B. Angiosperms B. Angiosperms - all flowering plants- all flowering plants

4. Seed and Fruit Development4. Seed and Fruit Development

- as seed develops, the ovary - as seed develops, the ovary surrounding it develops into a fruitsurrounding it develops into a fruit

- not all fruit is fleshy/edible!- not all fruit is fleshy/edible!

The Fleshy FruitsThe Fleshy Fruits

The Dry FruitsThe Dry Fruits

Watermelon in crazy shapes!Watermelon in crazy shapes!

So what is a fruit?So what is a fruit?Fruits have seeds!Fruits have seeds!

What about fruits without seeds?What about fruits without seeds?- Seedless fruits, or ‘Virgin fruits’ Seedless fruits, or ‘Virgin fruits’

- have been genetically engineered by humans have been genetically engineered by humans not to have seeds!not to have seeds!

OROR- Occur naturally through mutations! Occur naturally through mutations!

(bananas and watermelons!)(bananas and watermelons!)OROR- Seeds don’t develop if their not fertilized!Seeds don’t develop if their not fertilized!

(pineapple and cucumber!)(pineapple and cucumber!)

Pineapple Cucumbers Bananas

Watermelon

And what is a vegetable?And what is a vegetable?

Vegetables are every other part of the plant Vegetables are every other part of the plant that isn’t the ovary!that isn’t the ovary!

Onion – Root!

Carrot – Root!

Celery – Stem!

Lettuce – Leaves!

Broccoli – Whole plant! Little flowers at top!

C. Seed DispersalC. Seed Dispersal1. By 1. By AnimalsAnimals

a. a. fruitsfruits - animals - animals eat fruiteat fruit, seed pooped out, seed pooped out

b. b. sticky projectionssticky projections - “hitch-hikers” get - “hitch-hikers” get stuckstuck to animals, eventually fall or are picked offto animals, eventually fall or are picked off

Hitch-Hiker SeedsFruit Bat/Birds – Widest Dispersal

C. Seed DispersalC. Seed Dispersal2. By 2. By WindWind- little and lightlittle and light, may have “, may have “wingswings” ”

- ex. dandelion ex. dandelion

Dandelion

AcerTumbleweed

C. Seed DispersalC. Seed Dispersal

3. 3. WaterWater

--carried by water, buoyant carried by water, buoyant (float)(float)

-ex. coconut -ex. coconut

D. Seed Dormancy and GerminationD. Seed Dormancy and Germination

1. 1. DormancyDormancy - - embryo is alive, but not growingembryo is alive, but not growing

2. 2. GerminationGermination - - early growth stages of plantearly growth stages of plant

a. a. environmental conditionsenvironmental conditions will determine will determine if if seed germinatesseed germinates

1. 1. TemperatureTemperature

2. 2. MoistureMoisture

Plant ReproductionPlant Reproduction

Asexual Reproduction of Asexual Reproduction of Seed PlantsSeed Plants

A.A. Vegetative Reproduction Vegetative Reproduction - - asexualasexual production of new plants production of new plants

1. 1. Stolons Stolons - horizontal stems- horizontal stems

2. 2. PlantletsPlantlets - ‘little’ plants - ‘little’ plants

3. 3. Underground rootsUnderground roots

Grass - Stolons

Spider Plant - PlantletsAspen Tree –

Underground RootsLargest Organism!

106 acres!

B. Plant Propagation B. Plant Propagation - - humans using different ways to reproduce plantshumans using different ways to reproduce plants

1. 1. CuttingsCuttings - cut a stem off of and put it into soil - cut a stem off of and put it into soil

B. Plant Propagation B. Plant Propagation - - humans using different ways to reproduce plantshumans using different ways to reproduce plants

2. 2. Grafting and BuddingGrafting and Budding - plants are attached to - plants are attached to other plants in order to growother plants in order to grow

a. a. scionscion - the part of the plant being - the part of the plant being grafted; grafted; stems in grafting, buds in stems in grafting, buds in buddingbudding

b. b. stockstock - plant to which a scion is - plant to which a scion is attachedattached

Orange and Grapefruit Tree

Grafted Cactus Blooming

Pooktre! Tree Art!Pooktre! Tree Art!

Pooktre! Tree Art!Pooktre! Tree Art!

C. AgricultureC. Agriculture

1. Humans have been able to cultivate plants 1. Humans have been able to cultivate plants as food for centuries.as food for centuries.

2. Most people in the world depend on just 2. Most people in the world depend on just wheat, rice, and cornwheat, rice, and corn for the bulk of their for the bulk of their food supply.food supply.

Wheat CornRice