Lecture 4 Flashcards
What is the first step of seed development after seed maturation
embryogenesis
What are the two different patterns of embryogenesis
apical-basal and radial
What are the three types of tissues in a plant
epidermis, vascular, and ground tissue
What are the three primary meristems
protoderm, procambium, and ground meristem
What is protoderm
future epidermis, formed by divisions parallel to the surface in outermost cells of embryo
What is procambium
future vascular tissue
What is ground meristem
future ground tissue
How is embryogenesis the same in all angiosperms
polarity established, embryo proper and suspensor
Which end will form the large basil cell during the first stage of division
micropylar end
Where does the suspensor develop during the first stage of division
micropylar end
Before there is an actual embryo, what are the cells called
proembryo
What does the suspensor do
supports the development of the embryo through providing it nutrients and growth hormones then undergoes apoptosis
What limits the suspensor from going into another embryo
the embryo proper
Where does the developing embryo get its nutrients during embryogenesis
from the parent plant
What three things happen during seed maturation
Funiculus seperates and the seed desiccates, Metabolism slows down, and seed coat hardens
How do monocots and eudicts differ with food storage during development
monocots store food as endosperm, eudicots have cotyledons that absorb all the endosperm and store it in their leaves
What is the epicotyl
short stem above the hypocotyl that has 1-2 foliage leaves and then a shoot apical meristem
What is the plumule
embyronic shoot that is covered by the protective coleoptile
What is the coleorhiza
a protective sheath that covers the radicle
What is the pericarp
the mature ovary wall
What is germination
Resumption of growth of the embryo, Cell enlargement and cell division
What four external factors do seeds need to grow
water, oxygen, temperature, and light
What is dormancy
Fail to germinate even in favorable conditions
What are some causes of dormancy
Physiological immaturity, and impermeable seed coat
What are some examples to break dormancy
Pass through digestive tract, Rainfall, Mechanical cracking, Heat of fire, Light from canopy opening
What is the first structure to emerge from a growing seed
taproot (primary root)
What are characteristics of taproot
first structure to emerge, produces lateral roots, and short lived in monocots
What is the definition of epigeous
the type of seed germination in which the cotyledons are carried above ground level
Explain the process of epigeous
when the hook reaches the soil surface, it straightens out and pulls the cotyledons and plumule up into the air
What is the definition of hypogeous
the type of seed germination in which the cotyledons stay underground
Explain the process of hypogeous
the epicotyl is the structure that elongates and forms the hook, this protects the young leaves and shoot tip, as the epicotyl straightens out the plumule is raised above the soil surface, since elongation occurs above the cotyledons, they remain in the ground where they eventually decompose
Where do monocots get their food during germination
get food from endosperm
