Significance of Protein

Q. Almost all enzymes are proteins, so which enzyme is not a protein?

Q. In lac- operon, repressor protein binds to

1. regulator gene
2. operator gene
3. Promoter gene
4. Structural gene

Q.

Why is tRNA Called So?

Q.

The letter 'i ' in the regulatory gene of lac operon refers to ________.

1. inducer
2. inhibitor
3. inheritable

4. All of the above

Q. RNA intereference is a mechanism for silencing gene expression at the

1. post-transcriptional level
2. level of replication.
3. level of transcription
4. level of translation

Q. Regulatory proteins are the accessory proteins that interact with the RNA polymerase and affect its role in transcription. Which of the following statement is correct about regulatory proteins?

1. They only increase expression
2. They only decrease expression
3. They interact with RNA polymerase but do not affect expression
4. They can act both as activators and as repressors

Q. Identifying all the genes that are expressed as RNA can be done by:
[0.7 mark]

1. Sequence annotation
2. Expressed sequence tags
3. DNA fingerprinting
4. DNA polymorphism

Q. Which RNA carries the amino acids from the amino acid pool to mRNA during protein synthesis?

1. rRNA
2. mRNA
3. tRNA
4. hnRNA

Q. Aquatic organisms whose osmotic concentration of the body fluids change with that of the ambient water osmotic concentration are:

1. Osmoregulator
2. Thermoconformers
3. Osmoconformers
4. Thermoregulator

Q.

What type of RNA carries the Amino Acids?

Q. Select correct match with respect to lac-operon model?

1. 
   Active repressor + inducer → Inactive repressor
2. 
   Active repressor + corepressor → Inactive repressor
3. 
   Inactive repressor + inducer → Active repressor
4. 
   Inactive repressor + corepressor → Active repressor

Q. Which is true
(a) centromere is found in animal cells which produces extra during cell division
(b) insulin gene is present in every body cell
(c) nucleosome is formed of nucleotides

Q.

Name the enzyme which is not a protein?

Q. Select the correct option with respect to tailing.

1. It occurs at the 5' end of the mRNA
2. It involves addition of methyl guanosine triphosphate
3. Tailing occurs during replication
4. Addition of adenylate residues

Q.

Who discovered RNA interference?

Q.

Name the nucleic acid present in a cell.

Q. tRNA attaches amino acid to its:

1. 3' end
2. 5' end
3. Anticodon loop
4. DHU loop

Q. (a) What is an operon ?

(b) Explain how a polycistronic structural gene is regulated by a common promoter and a combination of regulatory genes in a lac-operon. [5]

Q. Hershey and Chase’s experiment proving DNA as the genetic material was based on the principle of

1. transduction
2. transformation
3. transcription
4. translation

Q. Which of these operons is anabolic in nature?

1. Lac
2. Ara
3. Trp
4. Both a and b

Q. Regarding the assertion and reason, select the correct option.
Assertion [A]: Proteins are very important biomolecules in a living organism.
Reason [R]: Proteins make up the enzymes responsible for almost all the chemical reactions in an organism.

1. Both A and R are true and R explains A
2. A is true and R is false
3. Both A and R are false
4. Both A and R are true, but R does not explain A

Q. How RNAi silences the mrna of nematode?

Q.

What is the main function of RNA interference?

Q. Lac operon is called negative regulation because__________

1. the repressor protein inhibits the transcription of structural genes.
2. it gets active only in presence of lactose
3. the structural genes can digest lactose
4. both b and c

Q. In the absence of this, the repressor protein binds to the operator and blocks the path of RNA polymerase and prevents the expression of structural genes.

1. Permease
2. Regulator
3. Promoter
4. Inducer

Q. In polypeptide synthesis, amino acids are brought over ribosome-mRNA complex by

1. rRNA
2. tRNA
3. DNA
4. Nucleotides

Q. What is meant by ORDER OF ISOLATION with respect to last roman number written while naming Restriction endonuclease?

Q. Which gene is connected with multiple phenotypes?

1. Polygenic inheritance
2. Epistasis
3. Pleiotropy
4. Hypostasis

Q. mma why operon concept is not present in eukaryotes??

Q. What is the difference between complementary gene and supplementary gene?