Botany Unit Botany Unit Notes Notes Part II
Jan 13, 2016
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