Dev. Bio

• found in snapdragon:
• prevents terminal flower formation
• suppresses FLO

• specifies floral meristem:
• stimulates CEN to prevent terminal flowers from forming

flowering plants that are regulated by photoperiod (day length)

• phytochromes-respond to red light (day)
• cryptochromes-respond to blue light (night)

8 hours or less of light

12 to 16 hours of light

• Whorl 1 (W1)-Sepals (Se)
• Whorl 2 (W2)-Petals (Pe)
• Whorl 3 (W3)-Stamens (St)
• Whorl 4 (W4)-Carpels (Ca)

Green "leaves" at base of flower

Petals of flower around W3 and W4

Within the flower on outside of pistil:

• Anther-contains pollen sacs that produce mail gametes
• Filament

Very center of flower that is comprised of:

• Stigma-top of pistil
• Style-neck of pistil
• Ovary with eggs-body of pistil

• leafy (lfy)
• apetala (ap1)
• cauliflower (cal)

• A homolog of flo
• A transcription factor
• Moves between cells in meristem before activating other flower genes

ap1 and cal are closely related and redundant-would need a double mutant to resemble broccoli/cauliflower

• Perfect flower:
• A required for sepals
• A+B required for petals
• B+C required for stamen
• C required for carpel

• 1-ABC gives leafs only
• 2-A mutants yield carpal and stamen
• 3-B mutants yield sepals and carpal
• 4-C mutants yield sepals and petals
• 5-B+C mutants yield all sepals
• 6-A+B mutants yield all carpals
• 7-A+C mutants yield hybrid petal and stamen 

• sporophyte-diploid, makes spores
• gametophyte-haploid, makes gametes

Circle starting at bottom:

Fertilization-Mitosis-Sporophytes-Spore mother cell-Meiosis-Spores-Mitosis-Gametophytes-Gametes

• sporophyte-makes spores
• dominant generation in angiosperm
• zygote produces seed (zygotes found in carpal)
• carpal becomes fruit
• fruit possibly eaten by animal
• seeds deposited/seeds germinate
• plant grows/plant produces flowers

• minor generation
• stamen produce pollen grains (microspores)

• Tube cell (n)-haploid, allows digestion of enzymes, allows for formation of generative cell
• Generative cell (n)-located inside tube cell
• Lands on stigma of pistil (may contain multiple carpals)

• One or more ovules attached by a "placenta" to the ovary wall
• Fully developed ovules called seeds
• Ovules produce 4 megaspores (n) (unequal cytokinesis)

• 3 of 4 will degenerate
• 4th megaspore (the largest) will mitotically divide producing 8 nuclei in 7 cells (embryo sac)

the endosperm-this becomes the food source

an embryo

• Stalk-attachment
• Nuclellus-nutritive tissue
• Integaments-exclose the nuclellus

(Didn't go over much in class)

• Dicots have 2 cotyldons
• Monocots have 1 cotyldon
• Suspensor-support tissue (will get squashed)
• Protoderm-epidermal layer of embryo