Developmental Biology

• Development is the process by which a multicellular organism arises, initially from a single cell.
• 5 stages of development: Growth, Cell Division, Differentiation, Pattern Formation, Morphogenesis
• Oviparity - eggs hatch outside mother
• Viviparity - embryo develops inside mother's body until birth
• Ovoviviparity - eggs hatch inside mother
• epigenesis - organs are formed de novo, anew at each generation
• Preformation - organs already present, fully formed into miniature form in one of the germ cells
• Plants develops by double fertilization
• Why is the development a gradual process?

  so that the complexity of the embryo increases progressively
• Berry

  Simple fleshy fruit
• Pepo

  Simple leathery fruit
• Drupe

  Simple hard stone fruit
• Hesperidium

  leathery and has succulent cavity and has oil glands
• Radial organization

  Rib, Peripheral Zone, and Central Zone
• Layer Organization

  Epidermal, Subepidermal, Corpus
• L1 + L2

  Tunica
• Dehiscent vs Indehiscent

  Fruit open at maturity vs Fruit that does not open at maturity
• Caryopsis vs Achene

  single seed that is attached to fruit wall vs not attached to fruit wall
• Follicle, Legume, Capsule

  one, two, and multiple sutures
• Aggregate fruit

  formed from a single flower with multiple free carpels
• Multiple fruit

  derived from more than a single flower that grows close to each other within a common stalk
• Accessory fruit

  has other plant tissues aside from the ovary
• Smallest and Largest Fruit

  Wolffia globosa and Atlantic giant pumpkin
• Primary signal for setting fruits

  Hormone
• what is a hormone?

  a chemical messenger that are required for the correct developmen
• A rich source of auxin

  pollen and a developing seed
• Main component of Pectin

  Galacturonic acid
• Main component of Middle Lamela

  Pectin
• Ripening hormone

  Ethylene
• Turgor

  pressure extended by the fluid inside the cell that presses the plasma membrane to cell wall
• Protruding structures of a seed that ant wants

  Elaiosome
• 3 parts of mature embryo in the seed

  Radicle, cotyledons, embryonic shoot
• an absolute requirement for germination

  Water
• absorption of water by dehyrdated seeds

  imbibition
• optimal temperature for most plant to germinate

  25 to 30C
• Oldest viable seeds

  Nelumbo nucifera
• Gravitropism

  Amyloplast
• Phototropism

  Phototropins
• "Touch" growth

  Thigmotropism
• protein from pollen that helps it avoid destruction/preserve it

  sporopollenin