July 23, 2021
In this IBDP Biology blog post, we will be understanding the specific plant type: Angiosperms, also known as a flowering plant, let's get to it!
Angiosperms
Angiosperms: Any plant that has a flower
Animals are used to facilitate the transfer of male pollen to female reproductive parts for fertilisation and seed development within the ovaries
2 classes of Angiosperms:
Monocots
- One cotyledon
- Parallel veins
- Vascular bundles are complexly arranged
- Floral parts are usually in multiples of three
Dicots
- Two cotyledons
- Netlike veins
- Vascular bundles arranged in rings and taproot usually present
- Floral parts in four or five
Control Flowering in Angiosperms
- Apical meristem produces more stem and leaves till it recieves a stimulus which makes it change to producing flowers (floral meristem)
- This switch is a change in gene expression in the shoot apex cells
The switch to flowering is in response to a stimulus: the length of light and dark periods (photoperiods) in plants
- Short day plant: Chrystanthemums
- Long day plant: Iris
SIGNIFICANT FACTOR: LENGTH OF NIGHT
Floral Initiation: Caused by the growth and differentiation of apical cells
- Cell in shoot apex change how they divide and differentiate - because of changes in gene expression
- The
triggers for change in gene expression vary between plants but the most common is day length
That's all!
References:
- https://www.google.com/url?sa=i&url=http%3A%2F%2Fib.bioninja.com.au%2Fhigher-level%2Ftopic-9-plant-biology%2Funtitled-3%2Fmonocots-versus-dicots.html&psig=AOvVaw1JoxCI4KUhi1GRyUqNtW6D&ust=1627147146992000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCOCL_c_Z-fECFQAAAAAdAAAAABAD
- https://www.google.com/url?sa=i&url=http%3A%2F%2Ffruitandnuteducation.ucdavis.edu%2Fgeneraltopics%2FAnatomyPollination%2FVegetativeFloral_Development%2F&psig=AOvVaw2MvwMRvfi2DRZ-rpf8kdA0&ust=1627147237983000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCLDcivzZ-fECFQAAAAAdAAAAABAD
Drafted by Venetia (Biology)