Explain the Watson - Crick Model of DNA.

Explain the Watson - Crick Model of DNA.
by

1 Answer

Answer :

The structure of DNA molecule resembles a spirally twisted ladder called double helix. It has a pair of polynucleotide chain running anti-parallel (run parallel to each other but with opposite alignments) to each other. Each polynucleotide unit consists of Deoxyribose sugar, phosphate and a nitrogenous base. The Deoxyribose sugar is a pentose sugar (C5H10O5). Each strand of the ladder is made up of Deoxyribose sugar and phosphate arranged alternatively. The nitrogenous bases connect the two opposite strands like the rungs of a ladder.
by

Related questions

Double helical structure model of the DNA was proposed by (A) Pauling and Corey (B) Peter Mitchell (C) Watson and Crick (D) King and Wooten

Description : Double helical structure model of the DNA was proposed by (A) Pauling and Corey (B) Peter Mitchell (C) Watson and Crick (D) King and Wooten

Last Answer : Answer : C

What is Watson and crick Model of DNA?

Description : What is Watson and crick Model of DNA?

Last Answer : Each DNA molecule is made of thousands of small units called nucleotides. There are four types of nucleotides in DNA. I. Adenine (A) nucleotides II. Thymine (T) nucleotides III. Cytosine (C) ... two stands formed of nucleotides. These two are linked with each other by cross bands like a ladder.

Describe the molecular model of DNA in brief as given by Watson and Crick.

Description : Describe the molecular model of DNA in brief as given by Watson and Crick.  

Last Answer : Ans: 1. DNA is double helical structure resembles a twisted ladder. 2. Each strand shows 5'→ 3' polarity and one strand is antiparallel to the other. Every strand has deoxyribonucleotides. 3 ... consists of 10 base pairs. The angle between the successive nucleotides of the same strand is 36o. 

Fluid mosaic model of cell membrane was put forward by (a) Danielli and Davson (b) Singer and Nicolson (c) Garner and Allard (d) Watson and Crick.

Description : Fluid mosaic model of cell membrane was put forward by (a) Danielli and Davson (b) Singer and Nicolson (c) Garner and Allard (d) Watson and Crick.

Last Answer : (b) Singer and Nicolson

DNA synthesis in laboratory was first achieved by (A) Watson and crick (B) Khorana (C) A.Kornberg (D) Ochoa

Description : DNA synthesis in laboratory was first achieved by (A) Watson and crick (B) Khorana (C) A.Kornberg (D) Ochoa

Last Answer : Answer : C

Which of the following events occurred first? (1) DNA structure of genes was discovered by James D Watson and Francis Crick (2) Yuri Gagarin became the first man in space (3) World's first human heart transplant was performed by Dr. Christian Barnard (4) World's first test tube baby Louise Brown was born in U.K.

Description : Which of the following events occurred first? (1) DNA structure of genes was discovered by James D Watson and Francis Crick (2) Yuri Gagarin became the first man in space (3) World's first human heart ... by Dr. Christian Barnard (4) World's first test tube baby Louise Brown was born in U.K.

Last Answer : (1) DNA structure of genes was discovered by James D Watson and Francis Crick Explanation: Discovery of DNA structure of genes: 25 April, 1953; Yuri Gagarin's feat of becoming the first man in space: ... human heart transplant: 3 December, 1967; and World's first test tube baby: 25 July, 1978.

DNA test was developed by – (1) Dr. Alec Jeffreys (2) Dr. V.K. Kashyap (3) Watson and Crick (4) Gregor Mendel

Description : DNA test was developed by – (1) Dr. Alec Jeffreys (2) Dr. V.K. Kashyap (3) Watson and Crick (4) Gregor Mendel

Last Answer : (3) Watson and Crick Explanation: A genealogical. DNA test looks at a person's genetic code at specific locations. Results give information about genealogy or personal ancestry. James D. Watson and Francis Crick are the two scientists who discovered the structure of DNA in 1953.

DNA mRNA C Proposed by Protein A B The figure gives an important concept in the genetic implication of DNA. Fill the blanks A, B and C. (a) A-Maurice Wilkins, B-Transcription, C-Translation (b) A-James Watson, B-Replication, C-Extension (c) A-Erwin Chargaff, B-Translation, C-Replication (d) A-Francis Crick, B-Translation, C-Transcription

Description : DNA mRNA C Proposed by Protein A B The figure gives an important concept in the genetic implication of DNA. Fill the blanks A, B and C. (a) A-Maurice Wilkins, B-Transcription, C-Translation ... c) A-Erwin Chargaff, B-Translation, C-Replication (d) A-Francis Crick, B-Translation, C-Transcription

Last Answer : (d) A-Francis Crick, B-Translation, C-Transcription

The diagram shows an important concept in the genetic implication of DNA. Fill in the blanks A to C. DNA mRNA Proposed by Protein C A B (a) A - Transcription, B -Translation, C - Francis Crick (b) A - Translation, B - Extension, C - Rosalind Franklin (c) A - Transcription, B - Replication, C - James Watson (d) A - Translation, B - Transcription, C - Ervin Chargaff

Description : The diagram shows an important concept in the genetic implication of DNA. Fill in the blanks A to C. DNA mRNA Proposed by Protein C A B (a) A - Transcription, B -Translation, C - Francis Crick (b) ... , B - Replication, C - James Watson (d) A - Translation, B - Transcription, C - Ervin Chargaff

Last Answer : (a) A - Transcription, B -Translation, C - Francis Crick

Which of the following events occurred first ? (1) DNA structure of genes was discovered by James D Watson and Francis Crick (2) Yuri Gagarin became the first man in space (3) World’s first human heart transplant was performed by Dr. Christian Barnard (4) World’s first test tube baby Louise Brown was born in U.K

Description : Which of the following events occurred first ? (1) DNA structure of genes was discovered by James D Watson and Francis Crick (2) Yuri Gagarin became the first man in space (3) World's first human heart ... by Dr. Christian Barnard (4) World's first test tube baby Louise Brown was born in U.K

Last Answer :  DNA structure of genes was discovered by James D Watson and Francis Crick

DNA test was developed by (1) Dr. Alec Jeffreys (2) Dr. V.K. Kashyap (3) Watson and Crick (4) Gregor Mendel

Description : DNA test was developed by (1) Dr. Alec Jeffreys (2) Dr. V.K. Kashyap (3) Watson and Crick (4) Gregor Mendel

Last Answer : Watson and Crick

Explain DNA finger print technology.

Description : Explain DNA finger print technology.

Last Answer : The technique in biotechnology used for identifying individuals by determining the genetic relationships is called DNA finger print technology. The technique involves breaking down the DNA of individual into short ... of size and net electrical charge. They get arranged to form a finger print.

Briefly explain DNA replication.

Description : Briefly explain DNA replication.

Last Answer : DNA replication is the process of producing two identical replicas from one original DNA molecule. The process of replication begins with the breaking of hydrogen bonds between the nitrogenous bases of ... . The assembly of nucleotides on the parent DNA template is brought about by some enzymes.

What is DNA finger print?

Description : What is DNA finger print?

Last Answer : The series of bands in the form of fingerprint with a unique pattern is called DNA finger print.

On what basis the short fragments of DNA arrange themselves?

Description : On what basis the short fragments of DNA arrange themselves?

Last Answer : The short fragments of DNA get separated on the basis of their size and net electrical charge.

Write the importance of gel electrophoresis during DNA finger print technology.

Description : Write the importance of gel electrophoresis during DNA finger print technology.

Last Answer : Gel electrophoresis helps to break down the DNA of an individual into short fragments from which a DNA finger print can be obtained.

What is meant by DNA finger print technology?

Description : What is meant by DNA finger print technology?

Last Answer : The technique in biotechnology used for identifying individuals by determining the genetic relationships is called DNA finger print technology.

Mention any two applications of recombinant DNA technology in a) Animals breeding b) Plant breeding

Description : Mention any two applications of recombinant DNA technology in a) Animals breeding b) Plant breeding

Last Answer : Recombinant DNA technology is used for improving the quality of animal breeds. It is used to transfer nitrogen fixing gene from the bacteria into plants to enable them to obtain nitrogen.

Mention one application of recombinant DNA technology.

Description : Mention one application of recombinant DNA technology.

Last Answer : Recombinant DNA technology is used to transfer nitrogen fixing gene from bacteria into plants which enable them to get nitrogen.

What is meant by recombinant DNA technology?

Description : What is meant by recombinant DNA technology?

Last Answer : The technique of manipulating the genes in the laboratory is called recombinant DNA technology. It involves the separation of desirable or useful gene from a cell and introduce it into another cell where it is made to express.

What is the significance of DNA technology?

Description : What is the significance of DNA technology?

Last Answer : Knowledge of DNA technology has led us to study the possibilities of many genetically related physical and physiological problems. Knowledge of DNA technology helps in improving the quality of ... applications in the field of agriculture, health, food management, conservation of environment etc.

Mention the significance of DNA.

Description : Mention the significance of DNA.

Last Answer : a) DNA has the coded information for controlling all the metabolic activities of the cell both directly and indirectly.b) By the property of self replication, it ensures the equal ... sometimes undergoes mutation and recombination which brings about variations in the characters of the off springs.

‘Replication of DNA is a significant phenomenon’. How?

Description : ‘Replication of DNA is a significant phenomenon’. How?

Last Answer : Replication of DNA ensures equal distribution of the genetic material to the future daughter cells.

What is meant by DNA replication?

Description : What is meant by DNA replication?

Last Answer : DNA replication is the process of producing two identical replicas from one original DNA molecule.

Give reason: The two strands of DNA molecule are complementary to each other but are not identical.

Description : Give reason: The two strands of DNA molecule are complementary to each other but are not identical.

Last Answer : The two strands of DNA are not identical because the nitrogenous bases are different in pairing. A purine base of one polynucleotide chain always pairs with a pyramidine base on the other. Adenine (A) pairs ... and Cytosine (C) pairs with Thymine (T). Hence the two strands of DNA are complementary.

Name the nitrogenous bases in a DNA molecule.

Description : Name the nitrogenous bases in a DNA molecule.

Last Answer : The four nitrogenous bases are Adenine (A), Guanine (G), Cytosine (C) and Thymine (T).

That some human diseases are genetically controlled was first established by (a) Gregor Mendel (b) A E Garrod (c) Watson and Crick (d) William Bateson

Description : That some human diseases are genetically controlled was first established by (a) Gregor Mendel (b) A E Garrod (c) Watson and Crick (d) William Bateson

Last Answer : Ans:(b)

Do you believe that Watson and crick went about their research in an ethical way why or why not?

Description : Do you believe that Watson and crick went about their research in an ethical way why or why not?

Last Answer : Need answer

Both α-helix and β-pleated sheet conformation of proteins were proposed by (A) Watson and Crick (B) Pauling and Corey (C) Waugh and King (D) Y.S.Rao

Description : Both α-helix and β-pleated sheet conformation of proteins were proposed by (A) Watson and Crick (B) Pauling and Corey (C) Waugh and King (D) Y.S.Rao

Last Answer : Answer : B

Transposable genetic elements (transposons) a. Were First Discovered By Watson And Crick. b. Are Smaller Than Insertion Sequences. c. Are Examples Of Plasmids. d. May Have Information For Antibiotic Resistance.

Description : Transposable genetic elements (transposons) a. Were First Discovered By Watson And Crick. b. Are Smaller Than Insertion Sequences. c. Are Examples Of Plasmids. d. May Have Information For Antibiotic Resistance.

Last Answer : d. May Have Information For Antibiotic Resistance.

Vitamin theory was proposed by (a) Hepkins and Funk (b) Holly and Khorana (c) Watson and Crick (d) Jensen and Meischer

Description : Vitamin theory was proposed by (a) Hepkins and Funk (b) Holly and Khorana (c) Watson and Crick (d) Jensen and Meischer

Last Answer : (a) Hepkins and Funk

Production of genetically modified plants is both a boon and bane. Explain.

Description : Production of genetically modified plants is both a boon and bane. Explain.

Last Answer : By genetically modifying plants we can increase the yield, improve the plant breeds, make them pest and disease resistant. We can also transfer nitrogen fixing gene. The greatest disadvantage of genetically modified plants is the sterility of seeds which is a threat to conservation of plant species.

Explain why there is deviation in the F1 generation of the 4’O clock plants with red and white flowers.

Description : Explain why there is deviation in the F1 generation of the 4’O clock plants with red and white flowers.

Last Answer : Red colour is expressed only in homozygous condition and the white colour is also expressed only in homozygous condition. But in heterozygous condition both the genes express. Hence intermediate pink coloured flowers are produced.

What is incomplete dominance? Illustrate and explain Carl Correns experiment of incomplete dominance.

Description : What is incomplete dominance? Illustrate and explain Carl Correns experiment of incomplete dominance.

Last Answer : When the results of monohybrid cross and dihybrid crosses do not follow the Mendel's principles then it is called incomplete dominance. Carl Correns conducted hybridization experiments using the ... pink flowers. This was deviation from Mendelian inheritance. This is called incomplete dominance.

Explain Mendel’s law of Independent Assortment.

Description : Explain Mendel’s law of Independent Assortment.

Last Answer : Combinations of characters which are not present in the parental forms are produced in the next generation. When there are two pairs of contrasting characters, the distribution of the members of one pair into the gametes is independent of the distribution of the other pair.

Explain Mendel’s law of segregation.

Description : Explain Mendel’s law of segregation.

Last Answer : The two pairs of factors separate during the formation of gametes. They do not blend but separate into different gametes. The gametes combine together by random fusion at the time of gamete formation.

Give reason: Though biotechnology is a boon to mankind, it may cause serious threat in future. OR Mention the limitations of biotechnology.

Description : Give reason: Though biotechnology is a boon to mankind, it may cause serious threat in future. OR Mention the limitations of biotechnology.

Last Answer : a) The use of biotechnology in plants has resulted in seed sterility which causes severe threat to the conservation of plant species. b) Genetically modified foods are a threat to human and ... , moral and cultural problems. e) Cloning can be used for illegal purposes and destructive activities.

Mention the applications of biotechnology.

Description : Mention the applications of biotechnology.

Last Answer : a) Biotechnology helps in large scaled synthesis of life saving drugs like antibiotics, vaccines, artificial hormones. b) It helps in improvement of plant and animal breeds, pests and pathogen ... used to transfer nitrogen fixing gene from bacteria into plants which enable them to get nitrogen.

Name the first clone and the person who developed it?

Description : Name the first clone and the person who developed it?

Last Answer : The first clone was a sheep called Dolly. It was developed by Dr.Wilmut.

What is meant by cloning?

Description : What is meant by cloning?

Last Answer : The group of molecules or cells or organism which is derived from the same parent by an asexual process is called a clone.

What is meant by cloning?

Description : What is meant by cloning?

Last Answer : The technique of obtaining genetically similar molecules, cells, tissues or organism from a common precursor invitro process is called cloning.

What is gel electrophoresis?

Description : What is gel electrophoresis?

Last Answer : The technique of breaking down the DNA of individual into short segments using specific enzymes is called gel electrophoresis.

What is meant by genetic engineering?

Description : What is meant by genetic engineering?

Last Answer : The technique of inducing desirable changes in the genetic material such as DNA of an organism is called genetic engineering.

What is meant by biotechnology?

Description : What is meant by biotechnology?

Last Answer : The application of technological procedures on organisms or their processes or their products to obtain new substances for human welfare is called biotechnology.

Mention the types of mutations. How do they occur?

Description : Mention the types of mutations. How do they occur?

Last Answer : Mutations are of two types – gene mutation and chromosome mutation. Gene mutation can occur naturally or it can be induced. Mutations are due to change in the base sequence of DNA.

What is meant by mutations?

Description : What is meant by mutations?

Last Answer : Any change in the structure or composition of genetic materials such as gene or chromosomes is called mutation.

Give reason: Genetic material present in the mother cell must get doubled.

Description : Give reason: Genetic material present in the mother cell must get doubled.

Last Answer : The daughter cells produced by cell division must receive the same genetic materials in same quantity so as to resemble the parent cell. Hence the genetic material present in the mother cells must be doubled.

What is meant by complimentary base pairing?

Description : What is meant by complimentary base pairing?

Last Answer : The pairing of Adenine (A) with Thymine (T) and Guanine (G) paring with Cytosine (C) is called complimentary base pairing.

What are purines and pyramidines?

Description : What are purines and pyramidines?

Last Answer : Nitrogenous bases Adenine (A) and Guanine (G) are called purines. Nitrogenous bases Cytosine (C) and Thymine (T) are called pyramidines.

What are nucleotides composed of?

Description : What are nucleotides composed of?

Last Answer : Each polynucleotide unit consists of Deoxyribose sugar, phosphate and a nitrogenous base.