Advertisements
Advertisements
Question
Answer the following question in your own words.
Describe the structure of the DNA molecule.
Advertisements
Solution
- All organisms have the same DNA structure. Watson and Crick modelled DNA in 1953. In this model, two parallel nucleotide threads coil around each other. A ‘double helix’ describes this arrangement. Like a coiled ladder, its construction is flexible.
- The DNA strands include many tiny ‘nucleotide’ molecules. Four nitrogenous bases are adenine, guanine, cytosine, and thymine. Cytosine and thymine are pyrimidines and adenine and guanine are purines.
- A nitrogenous base, phosphoric acid, and sugar molecule form the nucleotide.
- Four types of nitrogenous bases equal four types of nucleotides.
- DNA has a chain of nucleotides. Each ladder rail is constructed of alternately connected sugar and phosphoric acid molecules, like the DNA molecule's two threads. Every ladder step is two nitrogenous bases connected by hydrogen bonds. Adenine always connects with thymine, cytosine with guanine.
Structure of DNA
DNA (Watson and Crick’s Model)
APPEARS IN
RELATED QUESTIONS
Answer the following question in your own words.
Express your opinion about the use of DNA fingerprinting.
Fill in the blank:
DNA acts as director of ______ synthesis.
State whether the following sentence is true or false:
Each spiral of the DNA has 12 nucleotides.
State whether the following sentence is true or false:
Genes are arranged in a linear order on a chromosome.
State whether the following sentence is true or false:
In any specimen of DNA, the total molar amount of A + G = T+ C.
Choose the correct answer:
This structure is not present in all chromosomes ___________
Choose the correct answer :
DNA model was given by ___________
Give Technical Term:
The individual having similar pair of genes.
Multiple Choice Question:
The molecular knives of DNA are _______.
Multiple Choice Question:
Place the following event of translation in the correct sequence
i. Binding of met-tRNA to the start codon.
ii. Covalent bonding between two amino acids.
iii. Binding of second tRNA.
iv. Joining of small and large ribosome subunits.
New nucleotides are added and a new complementary strand of DNA is formed with the help of enzyme DNA polymerase.
Name the bond which binds the nucleotides in a DNA.
What is the biological significance of DNA?
____________ were used by Friedrich Miescher for his experiments.
A nucleoside differs from a nucleotide in not having a ______.
A unique chemical substance isolated from the nuclei of pus cells by Friedrich Miescher was initially named ______.
