Oxygen is the answer for this question.
#19
Polar nuclei fuse to produce Diploid secondary nucleus.
#20
After fertilisation the antipodal cells undergo meosis
#21
In which of the following double fertilisation occurs.
Ans:- Angiosperm s
#22..
In angiosperms pollen grains germinate on the Anther.
The building and or construction of proteins or polypeptides occurs at the small granule like organelle called the ribosome. These are small spherical structures either found on the rough endoplasmic reticulum or freely floating in the cytoplasm.