Lecture 14: Flowers & Fertilisation Flashcards
the main reproductive structure of the plant is known as the
flower
The main reproductive structure, the flower, is derived from
the shoot apical meristem
the function of the flower is to
generate gametes
2 systems of a plant
shoot & root
root system of a plant includes
- Taproot
- Lateral roots
Shoot system of a plant includes
- Flower
- Terminal bud (shoot apex)
- Node
- internode
- Axillary bud
- Terminal bud of branch
- Vegetative branch
- Leaf: Petiole & blade
- stem
standard floral structure =
- Receptacle
- Sepal
- Ovule
- Petal
- Stamen: Anther & Filament
- Carpel: Stigma, Style, Ovary.
Female gametes in flowers form
within the carpels
-The cells that form the gametes are not laid down early in development
(contrast with animals)
Male gametes in flowers form
within the stamens
-The cells that form the gametes are not laid down early in development
(contrast with animals)
Arabidopsis thaliana
- A model for studying plant development
- sequenced genome encoding c. 25000 genes
- short life cycle (seed-seed/3months)
- small (limited growth space)
- tools for identifying & characterising gene function
how to identify developmental genes using molecular genetics
•Create mutants with altered phenotype.
•Clone mutated gene responsible for phenotype.
•Examine where and when gene is expressed and what type of protein the gene encodes.
-Mutation leads to only a few combinations of flower parts
ABC model of flow formation
order= Sepal, petal, stamen, carpels, carpels, stamen, petal, sepal (SPSC)
-ABC forms triangle (aBc)
what determines organ fate
specific spatial/temporal combinations of transcription factors
ABC model: A domain gene =
A function alone = Sepal
ABC model: B domain gene =
A+B function = Petal