Molecular Basis of Inheritance BIOLOGY - Molecular Basis of Inheritance

The components of nucleotide are-

The formation of protein from m-RNA is called -

Both deoxyribose and ribose belong to a class of sugars called:

The transforming principle of Pneumococcus as found out by Avery, MacLeod and Mc Carty was:

Escherichia coli fully labelled with N15 is allowed to grow in N14 medium. The two strands of DNA molecule of the first generation bacteria have.

If the sequence of the coding strand in a transcription unit is written as follows:
5'-ATGCATGCATGCATGCATGCATGCATGC-3'
Write down the sequence of mRNA.

Briefly describe the following:
Bioinformatics.

Explain (in one or two lines) the function of the following:
tRNA.

If the sequence of one strand of DNA is written as follows:
5'-ATGCATGCATGCATGCATGCATGCATGC-3'
Write down the sequence of complementary strand in 5' → 3' direction.

Briefly describe the following:
Polymorphism.

Why is the Human Genome project called a mega project?

Group the following as nitrogenous bases and nucleosides:
Adenine, Cytidine, Thymine, Guanosine, Uracil and Cytosine.

If a double stranded DNA has 20 per cent of cytosine, calculate the per cent of adenine in the DNA.

List two essential roles of ribosome during translation.

Depending upon the chemical nature of the template (DNA or RNA) and the nature of nucleic acids synthesised from it (DNA or RNA), list the types of nucleic acid polymerases.

Differentiate between the following:

mRNA and tRNA.

What is DNA fingerprinting? Mention its application.

Which property of DNA double helix led Watson and Crick to hypothesise semi-conservative mode of DNA replication? Explain.

How did Hershey and Chase differentiate between DNA and protein in their experiment while proving that DNA is the genetic material?

Differentiate between the following:

Template strand and Coding strand.

In the medium where E. coli was growing, lactose was added, which induced the lac operon. Then, why does lac operon shut down some time after addition of lactose in the medium?

Differentiate between the genetic codes given below:

1. Unambiguous and Universal.
2. Degenerate and Initiator.

What are the characteristics of DNA?

With the help of a diagram explain the structure of DNA.

Who revealed biochemical nature of the transforming principle? How was it done?

For question, two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both assertion and reason are true, and reason is the correct explanation of assertion.
2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
3. Assertion is true, but reason is false.
4. Both assertion and reason are false

Assertion : Constitutive genes are continuously being expressed.

Reason : Constitutive genes are frequently needed for various metabolic functions.

For question, two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both assertion and reason are true, and reason is the correct explanation of assertion.
2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
3. Assertion is true, but reason is false.
4. Both assertion and reason are false.

Assertion: Sequences of bases in one polynucleotide chain of DNA can determine the sequence of bases in the other chain.

Reason: In a DNA, amount of adenine equals that of thymine and amount of guanine equals that of cytosine, i.e., A = T and C = G.

For question, two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both assertion and reason are true, and reason is the correct explanation of assertion.
2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
3. Assertion is true, but reason is false.
4. Both assertion and reason are false

Assertion: Regulator and operator genes are not associated with constitutive genes

Reason: Constitutive genes need not be repressed.

For question, two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both assertion and reason are true, and reason is the correct explanation of assertion.
2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
3. Assertion is true, but reason is false.
4. Both assertion and reason are false

Assertion: Ribosomes attached to endoplasmic reticulum release proteins into lumen of ER.

Reason: Such proteins are used for formation of hydrolytic enzymes or are modified.

For question, two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both assertion and reason are true, and reason is the correct explanation of assertion.
2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
3. Assertion is true, but reason is false.
4. Both assertion and reason are false.

Assertion: The concept of one gene-one enzyme was changed to one gene-one polypeptide.

Reason: Each enzyme may consist of two or more different polypeptides.

Why are vectors needed for replication of DNA during rDNA technology?

Read the following and answer any four questions from (i) to (v) given below:

In prokaryotes, DNA is circular and present in the cytoplasm but in eukaryotes, DNA is linear and mainly confined to the nucleus. DNA or deoxyribonucleic acid is a long polymer of nucleotides. In 1953, the first correct double-helical structure of DNA was worked out by Watson and Crick. Based on the X-ray diffraction data produced by Maurice Wilkins and Rosalind Franklin. It is composed of three components, i.e., A phosphate group, a deoxyribose sugar and a nitrogenous base. Different forms of DNA are B-DNA, Z-DNA, A-DNA, C-DNA and D-DNA.

1. Name the linkage present between the nitrogen base and pentose sugar in DNA.

1. Phosphodiester bond
2. Phosphodiester bond
3. Hydrogen bond
4. None of these

2. The double helix structure of DNA was proposed by.

1. James Watson and Francis Crick.
2. Earwin Chargaff
3. Federick Griffith
4. Hershey and Chase.

3. The double chain of B-DNA is coiled in a helical fashion. The spiral twisting of B-DNA duplex produces.

1. Right and left part.
2. Major and minor grooves.
3. Upper and lower side.
4. Linear and circular part.

4. Assertion: The two strands of DNA helix have uniform distance between them.

Reason: A large sized purine always paired opposite to a small sized pyrimidine.

1. Both assertion and reason are true and reason is the correct explanation of assertion.
2. Both assertion and reason are true but reason is not the correct explanation of assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

5. Which of the following describes the structure of B-DNA?

S.no	Polynudeotide chains	Polynudeotide chains
(a)	Parallel	5
(b)	Anti-parallel	10
(c)	Parallel	15
(d)	Anti-parallel	20

Read the following and answer any four questions from (i) to (v) given below:

Mutation explains the relationship between gene and DNA. The effects of large deletions and rearrangement in a segment of DNA results in loss or gain of gene and its function. Insertion or deletion of one or two bases changes the reading frame from the point of insertion or deletion. A classical example of point mutation is a change of single base pair in the gene for beta globin chain that results in change of amino acid residue glutamate to valine and results into a diseased condition called sickle cell anaemia.

1. A mutation is a change produced by an alteration in the genetic mechanism and.

1. May arise spontaneously.
2. Is always induced by the environment.
3. Is never advantageous.
4. Is not inherited.

2. The DNA code for glutamic acid is CTC or CTT. The code for valine is CAA or CAT. In sickle cell haemoglobin, valine is present instead of glutamic acid.

Assuming a single base pair substitution has occurred, what is the mRNA code in the affected mutant?

1. CUU
2. GAA
3. GAG
4. GUA

3. A mutation involving the substitution of one nitrogenous base for another has altered the base sequence of a DNA molecule, coding for four amino acids, as shown below.

Normal A-G-C-A-T-G-G-A-T-C-C-T

Mutant A-G-C-A-T-G-C-A-T-C-C-T

The table shows six codons and the corresponding amino acids into which each is translated.

mRNA codon	Amino acid
AAG	Lysine
CUA	Leucine
GGA	Glycine
GUA	Valine
UAC	Tyrosine
UCG	Serine

The mutation has changed the amino acid.

1. Leucine to valine.
2. Lysine to glycine.
3. Serine to leucine.
4. Tyrosine to lysine.

4. Assertion : Insertion or deletion of three or its multiple bases, insert or delete one or multiple codons and so one or multiple amino acids.

Reason: Reading frame remains unaltered with insertion or deletion of three or its multiple bases.

1. Both assertion and reason are true, and reason is the correct explanation of assertion.
2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
3. Assertion is true, but reason is false.
4. Both assertion and reason are false.

5. Part of the amino acid sequences in normal and sickle cell haemoglobin are shown.

Normal haemoglobin	Sickle cell haemoglobin
Thr-Pro-Glu-Glu	Thr-Pro-Val-Glu

mRNA codons for these amino acids are

Glutamine (Glu) GAA GAG

Praline (Pro) CCU CCC

Threonine (Thr) ACU ACC

Valine (Val) GUA GUG

Which transfer RNA molecule is involved in the formation of this part of the sickle cell haemoglobin?

Read the following and answer any four questions from (i) to (v) given below:
Translation is the process of polymerisation of amino acids to form a polypeptide. The order and sequence of amino acids are defined by the sequence bases in the mRNA. The amino acids are joined by a bond called peptide bond. Ribosome is the site of protein synthesis.

1. Which ion is essential for association of both units of ribosome at the time of protein formation?

1. Mg²⁺
2. Mn²⁺
3. CI^-
4. Ca²⁺

2. During translation, how many initiation factors are required in eukaryotes for initiation reactions?

1. 3
2. 6
3. 7
4. 9

3. Which part of mRNA contains untranslated regions (UTR)?

1. 3' end
2. 5' end
3. Either 3' or 5' end
4. Both 5' end and 3' end

4. Name the enzyme that helps in combining amino acid to its particular tRNA?

1. Activating enzyme
2. Amino-acyl tRNA-synthetas
3. PeptidyI transferase
4. Both (a) and (b)

5. From the given list, select the translation machinery.

1. mRNA
2. Ribosomes
3. Amino acids
4. tRNAs
5. Peptidyl transferase
6. Amino acyl tRNA synthetase
7. Pyrophosphatase

1. (1), (2), (3), (4) and (6)
2. (1), (2), (3), (4) and (5)
3. (1), (2), (3), (4), (5) and (6)
4. (1), (2), (3), (4), (5), (6) and (7)