What is Dichogamy protandry, protogyny and unisexuality and self sterility
Dichogamy as a condition for the pollination of flowers refers to the ripening of the anthers and stigma of a bisexual flower at different times
Dichogamy in flower occur in two different categories.
The two category of dichogamy are
Protandry and protogyny
So what does protandry mean
Protandry refers to the condition in which the answers of a flower mature earlier than the stigma of the same flower or flowers of same plant so much so that the pollen grain are only useful to flowers of other plant which have matured stigmas to receive them
What this means is that there are condition what this means is under the conditions in which anchor what this means is under the conditions in which answers of a flower ca what this means is that there are conditions in which anther of a flower come much earlier than anthers of flowers on the same plant
A situation where protandry of course in flower it means the other flower shop standing beside can benefit from the power of the pollen grain from the nature flower which the hunter a situation where protandry occurs in flower it means the other flower crop standing beside can benefit from the power of the pollen grain from the mature flower which the anthers and stigma and not right at the same time
What is protogyny as a condition for pollination to take place in flowers?
Protogyny can be referred to as a condition in which the stigma of a flower matures earlier than its own pollen grains or those of other flowers of the same species or the same plant.
A situation where the pollen grains of a particular flower much i a situation where the pollen grains of a particular flower much earlier than it stigma of those or flowers of the same plant so that it can only receive pollen grains from flowers of other plant it is known as protogyny
what is unisexuality as a condition for pollination to take place
The worl unisexuality simply means a situation in which some plant bear only one male or female flower.
The reality of sexuality in pollination is that both the male and female flowers do not exist on the same plant so in all of these cross pollination takes place. A typical example of cross-pollination taking place under universa a typical example of cross pollination taking place under unisexuality is a pawpaw tree
On the other hand in on the other hand in monoecious plant, the male and female flowers are Borne by the same plant.
In the case of monoecious plant th in the case of monoecious plant the pollen grains may not reach the stigma of the female flowers because they are situated higher than the place where the anthers are.
So to understand several conditions that are necessary for cross-pollination to take place we can also look at self sterility
What is self sterility?
Self sterility refers to a situation in which some plants make themselves sterile
Whenever any plan whenever any plant exhibit self sterility the presence of pollen grain on their stigmas is injurious to further development of plant
Whenever this occurs the plant may wither and die
But if pollen grain comes from other plant fertilization examples of self sterility are found in passion flowers and tea