Biol 156 Exam 1

• Synthesized from L-tryptophan
• Natural Auxin: IAA
• Synthetic Auxin: NAA, IBA, 2-4-D
• Synthesized in: Young leaves, primordia, & developing seeds
• Effects: Cell enlargement, cell division, vascular tissue differentiation, root initiationand apical dominance.

• Synthesized from: de novo form 5’ AMP (purines)
• Natural cytokinin: Zeatin.
• Synthetic cytokinin: BAP (N6-benzyl aminopurine).
• Site of synthesis: Root tips and developing seeds.
• Effects: Cell division and morphogenesis in tissue culture.

• Synthesized from: Ethylene is synthesized from methionine
• Site of synthesis: Most tissues in response to stress and in tissue undergoingprogrammed cell death or ripening..
• Effects: Release from dormancy, shoot and root growth and differentiation, leave and fruit abscission.

• Synthesized from: ABA is synthesized from mevalonic acid.
• Site of synthesis: Root and mature leaves.
• Effects: Stomatal closure, inhibition of shoot growth, negative regulation the effectsof gibberellins on α-amilase synthesis in cereal grain germination.

• Synthesized from: Gas are synthesized from geranylgeranyl diphosphate (GGDP).
• Site of synthesis: Young tissue of the shoot and developing seeds.
• Effects: Stem elongation, bolting in long day plants, induction of seed germination,induction of maleness in dioecious plants.

• Brassinosteroids
• Jasmonic acid
• Salicylic acid
• Polyamines
• Systemin (peptide hormone)
• ENOD40 (peptide hormone)

There is a correlation between hormone concentration and internodal growth

• S shaped curve
• Low response to low hormones
• Large response to more hormones
• Slows down again in response to a lot of hormones
• Could be result in change of receptor affinity

The process of becoming

• Faithfully followed blueprint
• Cell movement and gene expression
• Not influenced much by outside environment
• Single animal cell can only turn into entire animal up to certain point

• Always undergoing development
• Develop according to genetic blueprint but greatly influenced by environment & mediated by hormones
• Possibly due to lack of fixed development, differentiation is fully reversible
• Totipotent
• No gastrulation (cell migration)
• Adult plant structures develop from meristems
• Inability to move means plants had to evolve to handle fluctuating environments

Can be used to regenerate entire plant

• No circulatory System
• (stay small because no vascular system)

Have vascular system

475 million years

420 million years

• Waxy covering preventing desication
• Present in land plants, not green algae

• Special cellular array to permit gas exchange
• 4 cells working together (2 relax to open, tense to close)
• Closed during day, open at night

C3 & C4 (2 types of carbon molecules)

• Use organic molecules to capture and bind CO2 while stomata is open
• Close stomata when full
• Most desert plants are CAM

Gametangia

• Antheridium
• Produces sperm

• Archegonium
• Single egg

Within the archegonium

Alternate between mitosis and meiosis

Fertilization-> Sporophyte (2n) -> Spore Mother Cells -> Meiosis -> Spore (1n) -> Mitosis -> Gametophyte (1n) -> Male & Female

Diploid multicellular organism (most of plant)

Haploid multicellular organism (flower)

Each spore produces male OR female

1. Sporophyte (2n) -> Megasporangium -> Megaspore Mother Cells (in ovule) -> Meiosis -> Megaspore -> Female gametophyte (1n) -> female

2. Sporophyte (2n) -> Megasporangium -> Microspore Mother Cell (in anther) -> Meiosis -> Microspore -> Male gametophyte (1n) -> male

Zygote -> Embryo (in seed)

3n Endosperm (in seed) serves as nourishment for seed

Become 2 cell haploid polingrain

Divide 3 times to become 7 cells with 8 nucleii (embryo sac)

One central cell has 2 nucleii and gets fertilized to produce the endosperm which is 3n

• 2 Cotyledons
• Netted veination in leaves
• Vascular bundles in circles
• Taproot system

• 1 Cotyledon
• Parallel veination in leaves
• Scattered vascular bundles
• Fibrous root system