Embryogenesis and seed development Flashcards
What are the male reproductive segments of a flower?
The stamen, which includes:
- anthers
- filaments
What are the female reproductive segments of a flower?
The pistil, which includes:
- stigma
- style
- ovary
What is the calyx of a flower?
The ring of sepals (leaf like structure) which protects the flower during budding.
What is the purpose of petals?
To attract pollinators
Where does pollen develop?
In the anther of the stamen.
Where are egg cells developed?
In the ovules
What is the pedical?
The flower stem
What is the receptacle?
The base of the flower in which the pistil and all other structure sit upon. Found at the head of the stem (pedicel).
What are the segments of a fruit?
Seed and pericarp (surrounding tissue made up of 3 layers).
Where is the seed derived from?
The fertilised ovule of a flower.
What makes up the pericarp (3 layers)?
- Exocarp (outer layer) skin
- Mesocarp (mid layer) flesh
- Endocarp (inner layer) pit
Why do plants produce seeds?
- Facilitates dispersal as plants cannot move themselves
- Provides essential nutrients to young
- Can remain dormant until conditions are suitable
What are the main visible differences to distinguish monocots from dicots?
Monocots have:
- flower parts in threes. - pollen is round (mono-aperturate),
- have one cotyledon
- scattered vascular bundles
- parallel leaf venation
- fibrous roots
- rare secondary growth.
Dicots have:
- Flowers in fours or fives
- three dents in pollen (tri-aperturate
- two cotyledons
- network of venation
- a ring of vascular bundles
- a taproot
- common to have secondary growth
What are the 3 distinct stages of embryogenesis in dicots?
- Globular
- Heart
- Torpedo
What are the 3 distinct stages of embryogenesis in monocots?
- Globular
- Scutellar
- Coleoptilar
What is the globular stage of embryogenesis (both dicots and monocots)?
Cells divide rapidly.
What is the heart stage of embryogenesis (dicots)?
cotyledons begin to clearly form/emerge.
What is the torpedo stage of embryogenesis (dicots)?
Ground meristem forms around procambrium, this will eventually develop into the vascular tissues.
What us the scutellum stage of embryogenesis (monocots)?
A single cotyledon begins developing.
What is the coleptilar stage of embryogenesis (monocots)?
Differentiates the embryo axis into the plumule (gives rise to shoots) and radicle (gives rise to roots)
What is the main difference between the reserves of monocot and dicot seeds.
Monocots have an endosperm throughout that acts as storage.
Dicots absorb the endosperm storage reserves into the cotyledons during embryogenesis.
What are storage proteins in seen reserves?
Manage reserves for N, C, and S, these are found primarily in endosperm for monocots and in the cotyledons for dicots.
What are the two types of seed dormancy?
Coat-imposed prevented (growth by coating) or embryo dormancy (embryo remains immature, regulated by hormones)
What is the radicle?
The first organ to emerge through seed coat.
Anchors seedling to soil in germination.
Begins growing roots.
What is epigeous germination?
Cotyledons exposed above the ground.
What is hypogeous germination?
Cotyledons remains at ground level or underground.
