B.Sc

You can need to score more than 80% in order to take admission conveniently.

Kindly visit this link:
https://www.shiksha.com/science/course/b-sc-in-zoology-fergusson-college-fc-pune-fergusson-college-road-109830

The fee would be around INR 7000, one time payable.

If you want to go for M.Sc in microbiology or molecular biology then go for B.Sc in zoology rather botany because in microbiology and molecular biology as there is a great scope.

Yes, there is no gender issue in getting a government job for males in the nursing field. I have done B.Sc (Hons) in nursing, I did my practicals at Safdarjung Hospital. There we worked under the guidance of male staff too who worked there as a government employee. So, yes go for it. You will get a job in the government hospitals like AIIMS, Safdarjung and any other.
Good luck.

Yes, you can apply for B.Sc in Nursing. You are eligible for this.
Good luck.

According to me, for question papers, you should check their official website, you can get question papers there.
Good luck.

Yes, you can get admission for B.Sc in a government college with 70% marks but you will face problems in finding admission in DU north campus as their cut-offs are very high, chances are there to get admission in DU south campus and you can get admission in government universities located outside of Delhi and NCR region.
Good luck.

Hello,
You may refer below link for find B.Sc in physiology colleges. https://www.shiksha.com/science/colleges/colleges-Varanasi
Thanks.