Week 14 L5: Plant Development 3 - Embryo Development Flashcards
Do plants have an axis when they germinate?
YES, have a sense of polarity
Are meristems formed early in development of the embryo?
yes, it can be seen between globular and heart that meristems are becoming visible
What forms of the meristem show polarity in the embryo?
SAM and root meristem
What are the stages of embryogenesis?
globular , heart , torpedo , mature.
What is the relationship between embryo and endosperm development?
develop in tandem
What is the endosperm like when the seed is mature?
very little endosperm left, seed been taken up by the embryo.
What is a transient endosperm?
endosperm has virtually disappeared by germination. When the seed is mature there is very little endosperm left
What are the different types of endosperm?
transitive and persistent
What is germination?
the development of a plant from a seed or spore after a period of dormancy.
What plants have transitive endosperm?
arabidopsis
What type of plant have persistent endosperm?
barley grain (and other cereal grains)
What does a persistent endosperm mean?
it supports the germinating seedling
Why would cereals want a persistent endosperm?
It has a large source of calories.
In sweetcorn what is the largest source of calories in the endosperm?
starch
What is it about grains which make them a good food source?
double fertilisation and persistent endosperm.
What is syncytial development?
nuclei in the endosperm are just dividing. increase number of nuclei very quickly.
development of early endosperm
What happens in double fertilisation?
process of double fertilization occurs, since one of the nuclei of the pollen grain fuses with the two polar nuclei of the embryo sac to form a cell with three nuclei and the other fuses with the nucleus of the ovum.
What are the stages of endosperm development in embryogenesis?
free nuclear development
cellularization
cellular growth
What are the filial tissues?
endosperm and embryo
are apoplasmically separated from the maternal tissue