GRE Scores

Dear Anis, GRE scores make a difference if it is mandatory and depends on what you want to study and also your grades cum profile.

yes it is accepted

Since you have not mentioned the country, choose from the following list.
http://www.masterstudies.com/Masters-Degree/Biotechnology/

Dear Priyanka,
It depends upto admission criteria of university, most of the German university requires entrance exam score+ English test score.but few might give exemption for english test score subject to other conditions.so it is advisable that you should contact to admission counselor of particular university.
all the very best

Hello, every university offer scholarships to international students on merit basis, there is no single criteria. Scholarships by Australian universities are however tough to get and they are not amongst the financial aid givers.

Dear Steffi, 2 years is a pretty long time to study GRE & TOEFL as generally the students take 3 to 6 months to prepare & give the tests.
Since you are doing B.Sc which reflects your interest to pursue your Ms in USA BUT, to remind you that US universities would need a 16 years of education background or a US comparable degree to give you admission for their Ms courses.

you need both. IELTS. is a must to prove your English language test. GRE. if the University asks you have to do prove your engineering aptitude

No, there is no negative marking.