Download App

Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 ScienceBIOLOGYMolecular Basis of Inheritance5 Marks
Question
What are the characteristics of DNA?
✓

Answer

Following are some features of DNA:
  1. DNA is made up of two polynucleotide chains, where the backbone is made up of sugar and phosphate groups and the nitrogenous bases project towards the centre.
  2. There is complementary base pairing between the two strands of DNA.
  3. The two strands are coiled in right-handed fashion and are anti-parallel in orientation. One chain has a 5′ → 3′ polarity while the other has 3′ → 5′ polarity.
  4. The diameter of the strand is always constant due to pairing of purine and pyrimidine, i.e., adenine is complementary to thymine while guanine is complementary to cytosine.
  5. The distance between two base pairs in a helix is 0.34nm and a complete turn contains approximately ten base pairs. The pitch of the helix is 3.4nm and the two strands are righthanded coiled.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Long Answer Type Questions [5M]" from Molecular Basis of Inheritance→Molecular Basis of Inheritance — all question types→BIOLOGY STD 12 Science question papers→Bihar Board STD 12 Science question papers→Bihar Board question paper generator→

Similar questions

A pregnant human female was advised to undergo M.T.P. It was diagnosed by her doctor that the foetus she is carrying has developed from a zygote formed by an XX egg fertilised by Y–carrying sperms. Why was she advised to undergo M.T.P.?
→
  1. Work out a cross upto F, generation between two pure-bred pea plants, one bearing violet flowers and the other white flowers.
  2.  
  1. Name this type of cross.
  2. State the different laws of Mendel that can be derived from such a cross.
→
Draw a diagram and briefly describe the life cycle of Plasmodium.###Make a labeled diagram and briefly describe the various stages of the life cycle of Plasmodium.
→
  1. Explain taking one example of vertebrates anatomy that evolution of life has occurred on earth.
  2. 'Nature selects for fittest.' Explain with suitable examples.
→
Collect 5 examples of palindromic DNA sequences by consulting your teacher. Better try to create a palindromic sequence by following the base-pair rules.
→
Name the modern technology of crop improvement. How is it beneficial in crop improvement? Explain. ###Write an essay on tissue culture.
→
What is ecological succession? What is climax community? How is climax community established?
→
Draw a labelled diagram of L.S. of a flower to show the growth of pollen tube reaching egg apparatus.
→
Name the law that states that the sum of allelic frequencies in a population remains constant. What are the five factors that influence these values?
→
Write the function of following parts of sperm :
(i) head
(ii) middle piece
(iii) tail
→