Botany Unit NotesBotany Unit NotesPart II

Seed Producing Seed Producing PlantsPlants

Plants require water to photosynthesize sugars and make food

Many plants even need water for reproduction!

The evolution of seed plants did away with the need for water in reproduction

This was one reason leading to the success of seed plants on Earth

Seed Producing Seed Producing PlantsPlants

Seed plants form male and female gametes Sperm are the male gametes

and they are in the form of pollen

The female gamete is an egg Pollination is when a pollen

grain fuses with the egg cell of the female plant/organ

Advantages for Advantages for SeedsSeeds

Seeds nourish and protect plant embryos Under the right conditions a seed will

germinate (next slide) Seeds allow plants to be dispersed other

places Seeds can pass through the digestive system

of most animals without being damaged

Seed GerminationSeed Germination

Types of Seed Types of Seed PlantsPlants

There are Two types of Seed Plants: GymnospermsGymnosperms are seed plants

that do not produce fruits Most have cones as reproductive

organs like pine trees and cycads Gymnosperm means “naked seed”

AngiospermsAngiosperms are the flowering plants that do produce fruits and have flowers as reproductive organs

“enclosed seed”

GymnospermsGymnosperms GymnospermsGymnosperms make up 3 distinct

groups: Gnetophytes – phylum Gnetophyta

makes up about 70 species today and are considered “living fossils”

Cycads – phylum Cycadophyta are palm-like plants that reproduce using large cones and appeared around 225 mya!

Conifers – phylum Coniferophyta are the traditional “pine trees” making up the majority of Gymnosperms with 500 species

Conifer Life CycleConifer Life Cycle

AngiospermsAngiosperms Angiosperms are also called

flowering plants They have flowers as their

reproductive organs Angiosperms produce many

different kinds of fruits Fruits are considered the wall

of tissue surrounding the seed Fruits come in many forms

like an apple or a dandelion

AngiospermsAngiosperms Angiosperms owe

their success to their ability to attract pollinators and seed dispersers

Animals that eat the fruits can pass the seed through their digestive tracts and deposit the seed far away from the original plant!

The FlowerThe Flower Flowers have

male and female organs

Ovule = egg Pollen = sperm Pollen “stick” to

the top of the stigma and travel down the style to the ovary (pollination)

Angiosperm Life Angiosperm Life CycleCycle

Angiosperm Angiosperm DiversityDiversity

Angiosperms are the most diverse plant group on the planet with over 230,000 species!

We can categorize Angiosperms based on three traits: Monocots & Dicots (aka. Eudicots) Woody & Herbaceous Annuals, Biennials, and

Perennials

Monocot vs. Monocot vs. DicotDicot

Monocot vs. Monocot vs. DicotDicot

Monocots have fibrous roots while Dicots have taproots

Woody vs. Woody vs. HerbaceousHerbaceous

A plant’s stem is an identifying characteristic

It can be herbaceous when it is soft and easily cut with sheers

It can also be woody and be rough to the touch like the bark of a tree

Plant LifespanPlant Lifespan Plants can live anywhere from one

year to several years Annuals – are plants that mature

from seeds, produce flowers & fruit, and die all in one year

Biennials – are plants that take two years to complete their life cycle storing some of their nutrients in underground rhizomes at the end of the first year

Perennials – are any flowering plants that live for more than two years