Question 1

The inactive form of Bt toxin is converted to the active form in the insect gut __________.

Accepted Answer

Bt toxin is produced by the bacterium Bacillus thuringiensis in an inactive form called protoxin. When an insect ingests this inactive toxin, it enters the gut where the pH is alkaline. The alkaline pH of the insect gut solubilizes the protein crystals, converting the inactive protoxin into its active form. The active toxin then binds to the surface of midgut epithelial cells, creating pores that cause cell swelling and lysis, eventually leading to the death of the insect. Answer: due to alkalin

Question 2

The human protein named -1-antitrypsin, obtained from transgenic animals, is used for the treatment of :

Accepted Answer

Transgenic animals that produce useful biological products can be created by the introduction of the portion of DNA (or genes) which codes for a particular product. The human protein -1-antitrypsin is produced by transgenic animals and is used to treat emphysema. Similar attempts are being made for the treatment of phenylketonuria (PKU) and cystic fibrosis. Answer: Emphysema

Question 3

The toxin proteins, isolated from Bacillus thuringiensis , coded by which of the following genes would control cotton bollworms and corn borer, respectively ?

Accepted Answer

The toxin proteins encoded by the genes cryIAc and cryIIAb control the cotton bollworms. The toxin protein encoded by the gene cryIAb controls the corn borer. Therefore, the genes that control cotton bollworms and corn borer respectively are cryIAc and cryIAb. Answer: cryIAc and cryIAb

Question 4

Given below are two statements : Statement I : Transfer RNAs and ribosomal RNA do not interact with mRNA. Statement II : RNA interference (RNAi) takes place in all eukaryotic organisms as a method of

Accepted Answer

Both transfer RNAs and ribosomal RNA interact with mRNA. RNA interference (RNAi) takes place in all eukaryotic organisms as a method of cellular defence.

Question 5

Silencing of specific mRNA is possible via RNAi because of

Accepted Answer

RNAi (RNA interference) takes place in all eukaryotic organisms as a method of cellular defense. This method involves silencing of a specific mRNA due to a complementary dsRNA molecule that binds to and prevents translation of the mRNA.

Question 6

Which of the following genetically engineered organisms was used by Eli Lilly to prepare human insulin?

Accepted Answer

The correct answer is bacterium. In 1983, Eli Lilly, an American company, prepared two DNA sequences corresponding to ' A ' and ' B ' chains of human insulin and introduced them in plasmids of E.coli (a gram negative bacterium) to produce insulin chains.

Question 7

Match List I with List II : Choose the correct answer form the options given below:

Accepted Answer

The correct answer is option (2) as -I antitrypsin Is used for treatment of Emphysema Cry I Ab gene Controls corn borer Cry I Ac gene Controls cotton bollworms Enzyme replacement therapy Can be used as treatment option in ADA deficiency.

Question 8

The B t toxin in genetically engineered B t cotton kills the pest by:

Accepted Answer

Option (1) is the correct answer because the activated toxin binds to the surface of midgut epithelial cells and creates pore that cause cell swelling and lysis and eventually cause death of the insect. B t toxin doesn't kill pest by affecting their respiratory system, nervous system and it doesn't alter the pH of body fluids. So, options (2), (3) and (4) are not the answer.

Question 9

Given below are two statements : Statement I : RNA interference takes place in all Eukaryotic organisms as method of cellular defense. Statement II : RNAi involves the silencing of a specific mRNA due

Accepted Answer

The correct answer is option (1) because Statement I is correct which states that RNA interference takes place in all eukaryotic organisms as method of cellular defense and Statement II is incorrect which states that RNAi involved the silencing of a specific mRNA due to a complementary ssRNA molecule that binds and prevents translation of mRNA. In statement II, it should be complementary dsRNA molecule that is involved in silencing of a specific mRNA. Options (2), (3) and (4) are incorrect as th

Question 10

Given below are two statements: Statement I : Bt toxins are insect group specific and coded by a gene cry IAc. Statement II : Bt toxin exists as inactive protoxin in B. thuringiensis. However, after i

Accepted Answer

The correct answer is option (2) as specific Bt toxin genes were isolated from Bacillus thuringiensis and incorporated into the several crop plants such as cotton. The choice of genes depends upon the crop and the targeted pest as most Bt toxins are insect-group specific. The toxin is coded by a gene named cry. There are a number of them, for example, the proteins encoded by the genes cry IAc and cry IIAb control the cotton bollworms, that of cry IAb controls corn borer.

Question 11

Match List-I with List-II : array llll List-I & & List-II \ .Genetically engineered Human Insulin & I. & Gene therapy \ . GM Cotton & II.& E. coli \ . ADA Deficiency & III.& Antigen-antibody interacti

Accepted Answer

In genetically engineered human insulin, E. coli is used as host cell. For creating GM cotton, bacteria Bacillus thuringiensis is used. Gene therapy is one of the treatment for ADA deficiency. ELISA test is based on antigen-antibody interaction.

Biotechnology and Its Applications — Previous Year Questions & Solutions