If pollen tube enters the ovule directly through the micropyle it is called

If pollen tube enters the ovule directly through the micropyle it is called Porogamy
If the pollen tube enters the ovule through the chalaza it is called Chalazogamy.
If pollen tube enters the ovule either through integuments (eg. Cucurbita) or through the funiculus it is called Mesogamy
Transfer of pollen grains from anther to the stigma of a different plant is Xenogamy.