Sexual Reproduction in Flowering Plants

Which of the following is not a limiting factor for seed germination?
Give an example of a flower which contain both stamen and carpel.
Mention any one point of difference between perpsin and trypsin.
Which of the following parts of the flowering plants is haploid?
1) Ovary 
2) Pollen 
3) Egg 
4) Anther 
5) Zygote
$$512$$ microspores will be formed following meiosis of how many spores?
Why is vivipary an undesirable character for annual crop plants?