Why are plants important?

(Give 3 reasons)

• Flowering vascular plants
• Seeds that are covered by an ovule

• This is what develops from the flower's reproductive organ (ovule)
• It is a mature ovule
• Contains seeds 

• Flower = reproductive shoot that attaches to receptacle (stem)
• 4 floral organs on a flower: sepals, petals, stamens and carpels

False. 

The stamens and carpels are the reproductive organs

In angiosperms, the dominant generation is which of the following:

A. Gametophyte stage

B. Sporophyte stage 

B. Sporophyte stage

(This is the large plant that we see. Gametophytes are smaller and depend on sporophytes for nutrients)

"3 F's"

Flower, double Fertilization and Fruits

Complete Flowers - contain all 4 floral organs (ie. apple, roses)

Incomplete Flowers - lack one or more floral organs (ie. cucumbers and zucchini)

Clusters of flowers

ex. Umbels, Wild Carrots

• The transfer of pollen from anther to stigma
• Can occur by wind, water or animals 

Grapes - wind pollinated

Wheat - wind pollinated 

• Occurs when 2 sperm cels are discharged from pollen tube into embryo sac
• One sperm fertilizes the egg
• One sperm fertilizes the 2 polar nuclei (gives rise to endosperm)

• Stores nutrients to be used by seedling (in monocots)
• Food reserves are exported to cotyledons (in eudicots)

• It splits into a basal cell and terminal cell
• Basal cell produces a suspensor that anchors embryo to parent
• Terminal cell gives rise to most of embryo

• Flower parts in 3's
• Leaves in veins are parallel
• Primary root is replaced with fibrous root

• Flwoer parts in 4 or 5's
• Primary root usually becomes a tap root
• Leaves have net-like veins

• Embryo has 2 cotyledons
• Below cotyledon is embryonic axis called hypocotyl; above is epicotyl
• Radicle is embryonic root 

• 1 cotyledon called the scutellum
• Coleoptile covers young shoot (it's located above epicotyl)
• Coleorhiza covers young root
• Pericap is fused with seed coat

Can be physical or physiological

Physical - seed coat is impervious to water. Germination depends on being able to absorb water (must soften seed coat)

Physiological

1. Immature embryo; seed looks mature but embryo is not fully formed

2. Chemicals inhibit germination

3. Must alternate between cold and warm temperatures to break dormancy

• Species have staminate and carpellate flowers on seperate plants
• Seperate male and female flowers on same plant 
• Timing/Development of anthers

Staminate - only having functional stamen

Carpellate - only having funtional carpel

Meristem - area of concentrated cell division (growth point)

Apical Meristem - cells that become shoot of stem 

Monocots - scutellum emerges first; meristem is still underground and protected, thus exposure to stress will not kill it 

Dicot - damage to the hook will kill plant; once exposed, meristem is easily damaged by stresses (ie. frost)

• Simple - single or several fused carpels
• Aggregate - single flower with multiple seperate carpels (ie. Strawberries)
• Multiple - group of flowers called inflorescence (ie. Pineapple)
• Accesssory - other floral parts in addition to ovary (ie. Apples)

False. Flowering plants can produce sexually, asexually or both

Sexual - offspring are genetically different

Asexual - offspring are clones of parents; also called vegetative reproduction

The asexual reproduction of seeds from a diploid cell (no fusion of sperm and egg)

ie. Oranges, tangerines 

Means "virgin fruit". This is the production of fruit without fertilization of ovule; you get the fruit, but NO seeds

ie. Bananas 

Mass dividing undifferentiated cells that form where a stem is cut and produces adventitious roots 

ie. Sweet Potatoes 

Stock - provides root system

Scion - gets grafted onto stock

ie. Apple trees, grapes

Storage organs composed of shortened stems with thick fleshy leaves 

ie. Onions, lillies

• Also called runners
• These are above ground roots 
• ie. Stawberries 

Rhizome - stem that is usually underground (ie. Ginger)

Corms - solid, compressed stems that have nodes and internodes (ie. Gladiolus)

Tubers - modified stems that are storage organs and can also reproduce; these are formed on stolons (ie. Potatoes)

What are advantages and disadvantages of hybrids?

Adv - seed is uniform

Disadv - cannot keep seed for use next year

• More erratic weather patterns
• More flood, droughts, etc.
• More difficult to predict when rains will begin

• Relatively frost tolerant
• Seeds germinate at lower temperatures
• Storage at or near 0
• ie. Cabbage, carrots, peas, lettuce

• Not tolerant to frost
• Seeds germinate at warmer temperatures 
• Can receive chilling injuries
• ie. Tomatoes, peppers, sweet corn, sweet potatoes, soybeans, corn 

There was about a 10% yield loss for every 10 days that the temperature reaches 30 degrees or higher 

• Diversify crops
• Irrigation
• Mulches
• Compost
• Drough resistant crops

Queen Bee - only female that reproduces; one per hive

Worker bees - female bees with many functions

Drones - male bees; only function is to fertilize queen. They die after mating.

USA

The bees leave the hive and do not return; no worker bees 

• Bacteria (Prokaryote)
• Archaea (Prokaryote)
• Eukarya (ie. Animals, plants, fungi)

• Viruses
• Varroa Mites (Animalia) - suppresses immune system
• Nosema apis (Fungi) - invades digestive tract
• European foul brood (Bacteria) - infects larvae

Stamen - consists of a filament (stalk) and anther (terminal structure; pollen sacs located here)

Carpel - has ovary at the base, style (clear and slender neck) and stigma (tip of style that captures pollen)

Sepals - enclose and protect unopened floral buds

Petals - bright in colour