The charge present on the DNA backbone is negative. The force required to accelerate the molecules toward
anode is directly proportional to no. of
(a) Sugar molecules
(b) Phosphate group
(c) Nitrogenous base
(d) Both phosphate and sugar molecules
Correct answer: (B) Phosphate group
Explanation:
The negative charge on the DNA backbone is due to the phosphate groups in the sugar-phosphate backbone.
- Each phosphate group (PO₄³⁻) carries a negative charge, making DNA a negatively charged molecule.
- During electrophoresis, the negatively charged DNA moves toward the anode (+) under the influence of an electric field.
- The force required to accelerate the DNA molecules is directly proportional to the number of phosphate groups, because each nucleotide contributes one phosphate group to the backbone.
Why Not the Other Options?
-
(A) Sugar molecules ❌
- The deoxyribose sugar in DNA does not contribute to the charge; it only provides structural support.
-
(C) Nitrogenous base ❌
- The bases (A, T, G, C) are uncharged at neutral pH, so they do not influence DNA’s migration in electrophoresis.
-
(D) Both phosphate and sugar molecules ❌
- While the sugar is part of the backbone, it does not carry a charge; only phosphate groups contribute to the negative charge.
Final Answer:
✅ (B) Phosphate group
58 Comments
Prami Masih
February 27, 2025Okay sir
Mahima Sharma
August 24, 2025Phosphate group
Arushi
April 1, 2025👍✔️
Anurag Giri
August 13, 2025Ans 2 bcoz The negative charge on the DNA backbone is due to the phosphate groups in the sugar-phosphate backbone.
Khushi Agarwal
August 13, 2025Option b is correct
Negative charge comes from phosphate group on DNA
Aman Choudhary
August 13, 2025option b is correct because of phosphate group
Soniya Shekhawat
August 13, 2025Option B is correct because DNA is negative charge due to by phosphate group are present in a DNA which is negatively charged…
Mohd juber Ali
August 14, 2025Option (B) is right bcz
(pH is more OH ion is more = -ve charge so aa move toward anode +ve electrode )
DNA ki backbone per negative charge phosphate group k karan hota h so negative charge anode electrode ki taraf move karta h
Priya dhakad
August 14, 2025The force required to accelerate the DNA molecules is directly proportional to the number of phosphate groups
Priya dhakad
August 14, 2025Option B is correct phosphate group
Anjani sharma
August 14, 2025Option b is correct negative charge on DNA is due to phosphate group
Mansukh Kapoor
August 14, 2025The correct answer is option 2nd
Negative charge on DNA is due to the phosphate group and no. of the phosphate group is directly proportional to the force required to pull it towards the anode
Karishma Don
August 14, 2025the phosphate group in dna is -ve charge so to accelerate the dna mol. towards anode the conc. of phosphate group should be high.
Sneha Kumawat
August 14, 2025The correct answer is phosphate group , phosphate group is negatively charge
Priyanka choudhary
August 15, 2025Correct answer is option B, because phosphate group nagetive charged hota h
Khushi Mehra
August 14, 2025Dna is negatively charged due to presence of phosphate group
Dipti Sharma
August 14, 2025(B) Phosphate group bcz it is responsible for negative charge
Deepika Sheoran
August 14, 2025Option b is correct answer
Negative charge comes from phosphate group on DNA.
Neelam Sharma
August 14, 2025Phosphate group
Priti khandal
August 14, 2025Phosphate group bcz it s responsible for negative charge
Priya khandal
August 14, 2025Phosphate group
Mitali
August 15, 2025(B) Phosphate group
shruti sharma
August 15, 2025phosphate group
Shivani
August 15, 2025Phosphate group is responsible for negetive charge on DNA
Divya rani
August 16, 2025Dna is negatively charged due to phosphate group so during electrophoresis dna moves towards anode which is a post ice electrode under electric field. So answer is B.
Aafreen
August 17, 2025Ans -2
DNA backbone is negatively charge due to phosphate group, so it’s move towards anode electrode which is positively charged
Kavita choudhary
August 17, 2025phosphate group
Kajal
August 17, 2025Phosphate group
Avni
August 17, 2025DNA is negatively Charged due to phosphate group
Neeraj Sharma
August 18, 2025In DNA the negative charge is because of phosphate group attached with the sugar molecule hence the negative charge on DNA is due to phosphate group so option B is correct
Bharti Yadav
August 24, 2025The negative charge on the DNA backbone is due to the phosphate groups
Priyanka choudhary
August 24, 2025B is right answer, because
Negative charge comes from phosphate group on DNA
Bhavana kankhedia
August 24, 2025Phosphate group
Anil Choudhary
August 24, 2025Phosphate group
Sonam Saini
August 24, 2025फास्फेट ग्रुप
Alec
August 24, 2025option b – phosphate group because force required to accelerate molecules towards anode is directly proportion to no. of phosphate groups.
Niti Tanwar
August 24, 2025Dna is negetive charged due to Phosphate group
Anjali
August 24, 2025DNA backbone is negatively charge due to phosphate group .
Aartii sharma
August 24, 2025Phosphate group
Anju
August 24, 2025Ans : b
As dna moves to anode and phosphate carries -ve charge
Falguni Prakash
August 24, 2025Negative charge is due to phosphate group
Kashish yadav
August 25, 2025Phosphate group
Ayush Dubey
August 25, 2025Phosphate group
sakshi khatri
August 25, 2025done
Devika
August 25, 2025Phosphate group
Surendra Doodi
August 28, 2025The negative charge on the DNA backbone is due to the phosphate groups in the sugar-phosphate backbone.and anode have positive charge….
Pratibha Jain
August 30, 2025Correct answer is option (B)
Phosphate group
Shriyanshi verma
August 30, 2025Option b is correct
Negative charge comes from phosphate group on DNA
Sheikh Aleen
August 30, 2025Phosphate group
Patel Radha
August 30, 2025Phosphate group
Anisha Beniwal
August 31, 2025Phosphate group
Vanshika Sharma
August 31, 2025DNa backbone is negatively charged due to phosphate group
Shobha Kanwar
August 31, 2025Option b is correct negative charge on DNA is due to phosphate group
Anisha jakhar
September 3, 2025(B) Phosphate group
Muskan Yadav
September 3, 2025Phosphate group
Somya Yadav
September 5, 2025Phosphate group
Meera Gurjar
September 13, 2025Phosphate group
Aakansha sharma Sharma
October 1, 2025Phosphate group is responsible for negetive charge on DNA