What are retroviruses? How do they reproduce and what is the role of the enzyme reverse transcriptase?

What are retroviruses? How do they reproduce and what is the role of the enzyme reverse transcriptase?
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Retroviruses are viruses whose genetic material is RNA. HIV and the virus of SARS (severe acute respiratory syndrome) are examples of retrovirus. These viruses inoculate their RNA into the host cell and within the cell the viral RNA is reversely transcripted into DNA. DNA made from the viral RNA then commands the synthesis of viral proteins for the assemblage of new viruses and the breaking of the host cell to liberate them outside. The enzyme reverse transcriptase is the catalyst of the reverse transcription of RNA into DNA. The enzyme is part of the virus and it is also inoculated into the host cell. Virus Review - Image Diversity: retrovirus
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Retroviruses are so-named because their reverse transcriptase _____. a. reverses the flow of genetic information by stimulating information to proceed from RNA to DNA. b. reverses the normal multiplication of cells from a low rate to a high rate. c. reverses the ability of viruses to associate with cells. d. reverses the action of drugs on viruses and allows them to continue multiplying in living cells.

Description : Retroviruses are so-named because their reverse transcriptase _____. a. reverses the flow of genetic information by stimulating information to proceed from RNA to DNA. b. reverses the normal ... the action of drugs on viruses and allows them to continue multiplying in living cells.

Last Answer : a. reverses the flow of genetic information by stimulating information to proceed from RNA to DNA.

In which organism did the reverse transcriptase enzyme which performs DNA synthesis from RNA templates first appear?

Description : In which organism did the reverse transcriptase enzyme which performs DNA synthesis from RNA templates first appear?

Last Answer : Need answer

HIV often changes its shape due to the presence of an enzyme called (1) Reverse Transcriptase (2) Enterokinase (3) Nucleotidase (4) Nucleoditase

Description : HIV often changes its shape due to the presence of an enzyme called (1) Reverse Transcriptase (2) Enterokinase (3) Nucleotidase (4) Nucleoditase

Last Answer : (1) Reverse Transcriptase Explanation: Use of the reverse transcriptase enzyme is a unique characteristic of retroviruses such as HIV. After the virus releases its genetic material into a host cell, ... viral RNA into a complementary piece of DNA. This process is known as 'reverse transcription'.

The enzyme reverse transcriptase helps in the

Description : The enzyme reverse transcriptase helps in the

Last Answer : synthesis of DNA in the host cell.

HIV often changes its shape due to the presence of an enzyme called (1) Reverse Transcriptase (2) Enterokinase (3) Nucleotidase (4) Nucleoditase

Description : HIV often changes its shape due to the presence of an enzyme called (1) Reverse Transcriptase (2) Enterokinase (3) Nucleotidase (4) Nucleoditase

Last Answer : Reverse Transcriptase

Another name for reverse transcriptase is (A) DNA dependent DNA polymerase (B) DNA dependent RNA polymerase (C) RNA dependent DNA polymerase (D) RNA dependent RNA polymerase

Description : Another name for reverse transcriptase is (A) DNA dependent DNA polymerase (B) DNA dependent RNA polymerase (C) RNA dependent DNA polymerase (D) RNA dependent RNA polymerase

Last Answer : Answer : C

DNA directed RNA polymerase is (A) Replicase (B) Transcriptase (C) Reverse transcriptase (D) Polymerase III

Description : DNA directed RNA polymerase is (A) Replicase (B) Transcriptase (C) Reverse transcriptase (D) Polymerase III

Last Answer : Answer : B

The only correct statement about oncoviruses is (A) All the oncoviruses are RNA viruses (B) Reverse transcriptase is present in all oncoviruses (C) Viral oncogenes are identical to human protooncogens (D) Both DNA and RNA viruses can be oncoviruses

Description : The only correct statement about oncoviruses is (A) All the oncoviruses are RNA viruses (B) Reverse transcriptase is present in all oncoviruses (C) Viral oncogenes are identical to human protooncogens (D) Both DNA and RNA viruses can be oncoviruses

Last Answer : Answer : D

Reverse transcriptase catalyses (A) Synthesis of RNA (B) Breakdown of RNA (C) Synthesis of DNA (D) Breakdown of DNA

Description : Reverse transcriptase catalyses (A) Synthesis of RNA (B) Breakdown of RNA (C) Synthesis of DNA (D) Breakdown of DNA

Last Answer : Answer : C

All of the following statements about RNA-dependent DNA polymerase are true except: (A) It synthesizes DNA using RNA as a template (B) It is also known as reverse transcriptase (C) It synthesizes DNA in 5’→3’ direction (D) It is present in all the viruses

Description : All of the following statements about RNA-dependent DNA polymerase are true except: (A) It synthesizes DNA using RNA as a template (B) It is also known as reverse transcriptase (C) It synthesizes DNA in 5’→3’ direction (D) It is present in all the viruses

Last Answer : Answer : D

Reverse transcriptase activity is present in the eukaryotic: (A) DNA polymerase α (B) DNA polymerase γ (C) Telomerase (D) DNA polymerase II

Description : Reverse transcriptase activity is present in the eukaryotic: (A) DNA polymerase α (B) DNA polymerase γ (C) Telomerase (D) DNA polymerase II

Last Answer : Answer : C

Reverse transcriptase is capable of synthesising (A) RNA → DNA (B) DNA → RNA (C) RNA → RNA (D) DNA → DNA

Description : Reverse transcriptase is capable of synthesising (A) RNA → DNA (B) DNA → RNA (C) RNA → RNA (D) DNA → DNA

Last Answer : Answer : A

RNA interference involves (a) synthesis of cDNA and RNA using reverse transcriptase (b) silencing of specific mRNA due to complementary RNA (c) interference of RNA in synthesis of DNA (d) synthesis of mRNA from DNA

Description : RNA interference involves (a) synthesis of cDNA and RNA using reverse transcriptase (b) silencing of specific mRNA due to complementary RNA (c) interference of RNA in synthesis of DNA (d) synthesis of mRNA from DNA

Last Answer : (b) silencing of specific mRNA due to complementary RNA

At which stage of HIV infection does one usually show symptoms of AIDS? (a) Within 15 days of sexual contact with an infected person (b) When the infected retro virus enters host cells (c) When HIV damages large number of helper T  - lymphocytes (d) When the viral DNA is produced by reverse transcriptase

Description : At which stage of HIV infection does one usually show symptoms of AIDS? (a) Within 15 days of sexual contact with an infected person (b) When the infected retro virus enters host cells (c) ... large number of helper T  - lymphocytes (d) When the viral DNA is produced by reverse transcriptase

Last Answer : (c) When HIV damages large number of helper T  - lymphocytes

Which of the following is correct regarding AIDS causative agent HIV? (a) HIV is enveloped virus containing one molecule of single-stranded RNA and one molecule of reverse transcriptase. (b) HIV is enveloped virus that contains two identical molecules of single-stranded RNA and two molecules of reverse transcriptase. (c) HIV is unenveloped retrovirus. (d) HIV does not escape but attacks the acquired immune response

Description : Which of the following is correct regarding AIDS causative agent HIV? (a) HIV is enveloped virus containing one molecule of single-stranded RNA and one molecule of reverse transcriptase. (b) HIV ... ) HIV is unenveloped retrovirus. (d) HIV does not escape but attacks the acquired immune response

Last Answer : (d) HIV does not escape but attacks the acquired immune response.

The following are true about DNA synthesis: a. it requires DNA polymerase b. reverse transcriptase enzymes are involved c. moves in a 5'---> 3' direction d. the rate of error in DNA synthesis is 1 in 105 base pairs

Description : The following are true about DNA synthesis: a. it requires DNA polymerase b. reverse transcriptase enzymes are involved c. moves in a 5'---> 3' direction d. the rate of error in DNA synthesis is 1 in 105 base pairs

Last Answer : it requires DNA polymerase

Which one of the following makes use of RNA template to synthesise DNA? (a) DNA polymerase (b) RNA polymerase (c) Reverse transcriptase (d) DNA dependant RNA polymerase

Description : Which one of the following makes use of RNA template to synthesise DNA? (a) DNA polymerase (b) RNA polymerase (c) Reverse transcriptase (d) DNA dependant RNA polymerase

Last Answer : c) Reverse transcriptase

Which of the following viruses is a retrovirus with reverse transcriptase? a. HPV b. polio c. HIVd. Ebola

Description : Which of the following viruses is a retrovirus with reverse transcriptase? a. HPV b. polio c. HIV d. Ebola

Last Answer : c. HIV

The initial regimen for antiretroviral therapy of previously untreated HIV patient consist of: A. Two nucleoside reverse transcriptase inhibitors (NRTIs) + one protease inhibitor (PI) B. Two NRTIs + one non-NRTI C. Three NRTIs D. Any of the above

Description : The initial regimen for antiretroviral therapy of previously untreated HIV patient consist of: A. Two nucleoside reverse transcriptase inhibitors (NRTIs) + one protease inhibitor (PI) B. Two NRTIs + one non-NRTI C. Three NRTIs D. Any of the above

Last Answer : D. Any of the above

ndicate the anti-HIV regimen that is generally reserved for advanced cases of AIDS or for repeated treatment failures: A. Two nucleoside reverse transcriptase inhibitors (NRTIs) + one protease inhibitor (PI) B. Three NRTIs C. Two NRTIs + one non-NRTI D. One NRTI + one non-NRTI + one PI

Description : ndicate the anti-HIV regimen that is generally reserved for advanced cases of AIDS or for repeated treatment failures: A. Two nucleoside reverse transcriptase inhibitors (NRTIs) + one protease inhibitor (PI) B. Three NRTIs C. Two NRTIs + one non-NRTI D. One NRTI + one non-NRTI + one PI

Last Answer : D. One NRTI + one non-NRTI + one PI

According to current guidelines, previously untreated symptomatic HIV patients should be treated with: A. Zidovudine alone B. Zidovudine + zalcitabine C. Zidovudine + indinavir D. Any two nucleoside reverse transcriptase inhibitors + one protease inhibito

Description : According to current guidelines, previously untreated symptomatic HIV patients should be treated with: A. Zidovudine alone B. Zidovudine + zalcitabine C. Zidovudine + indinavir D. Any two nucleoside reverse transcriptase inhibitors + one protease inhibito

Last Answer : D. Any two nucleoside reverse transcriptase inhibitors + one protease inhibitor

Select the drug which directly inhibits HIV-reverse transcriptase without the need for intracellular activation by phosphorylation: A. Nelfinavir B. Nevirapine C. Stavudine D. Didanosine

Description : Select the drug which directly inhibits HIV-reverse transcriptase without the need for intracellular activation by phosphorylation: A. Nelfinavir B. Nevirapine C. Stavudine D. Didanosine

Last Answer : B. Nevirapine

Proto-oncogenes are: B A. DNA sequences in cells that are oncogenes themselves B. Cellular copies of genes that were first found in oncogenic retroviruses C. DNA viral sequences that are known to infect human cells D. Bacterial DNA counterparts

Description : Proto-oncogenes are: B A. DNA sequences in cells that are oncogenes themselves B. Cellular copies of genes that were first found in oncogenic retroviruses C. DNA viral sequences that are known to infect human cells D. Bacterial DNA counterparts

Last Answer : Cellular copies of genes that were first found in oncogenic retroviruses

Proto-oncogenes: a. are only found in malignant tissues b. are retroviruses capable of causing tumouc. inactivates oncogenes d. regulates cell growth and differentiationr

Description : Proto-oncogenes: a. are only found in malignant tissues b. are retroviruses capable of causing tumour c. inactivates oncogenes d. regulates cell growth and differentiation

Last Answer : regulates cell growth and differentiation

Which of the following statements is not true for retroviruses? (a) DNA is not present at any stage in the life cycle of retroviruses. (b) Retroviruses carry gene(c) The genetic material in mature retroviruses is RNA. (d) Retroviruses are causative agents for certain kinds of cancer in man. for RNA-dependent DNA polymerase.

Description : Which of the following statements is not true for retroviruses? (a) DNA is not present at any stage in the life cycle of retroviruses. (b) Retroviruses carry gene for RNA-dependent DNA ... mature retroviruses is RNA. (d) Retroviruses are causative agents for certain kinds of cancer in man.

Last Answer : (a) DNA is not present at any stage in the life cycle of retroviruses

RNA directed DNA polymerase is (A) Replicase (B) Transcriptase (C) Reversetranscriptase (D) Polymerase–III

Description : RNA directed DNA polymerase is (A) Replicase (B) Transcriptase (C) Reversetranscriptase (D) Polymerase–III

Last Answer : Answer : C

Manipulation of DNA in genetic engineering became possible due to the discovery of (a) restriction endonuclease (b) DNA ligase (c) transcriptase (d) primase

Description : Manipulation of DNA in genetic engineering became possible due to the discovery of (a) restriction endonuclease (b) DNA ligase (c) transcriptase (d) primase

Last Answer : (a) restriction endonuclease

One of the first enzymes synthesized by many bacteriophage is __________ , an RNA dependent RNA polymerase A.RNA transcriptase B.RNA polymerase C.RNA ligase D.RNA replicase

Description : One of the first enzymes synthesized by many bacteriophage is __________ , an RNA dependent RNA polymerase A.RNA transcriptase B.RNA polymerase C.RNA ligase D.RNA replicase

Last Answer : D.RNA replicase

Advantages of angiotensin converting enzyme inhibitors as antihypertensive include the following except: A. They tend to reverse left ventricular hypertrophy B. Their efficacy is not reduced by nonsteroidal antiinflammatory drugs C. They do not worsen blood lipid profile D. They do not impair work performance

Description : Advantages of angiotensin converting enzyme inhibitors as antihypertensive include the following except: A. They tend to reverse left ventricular hypertrophy B. Their efficacy is not reduced by nonsteroidal ... . They do not worsen blood lipid profile D. They do not impair work performance

Last Answer : B. Their efficacy is not reduced by nonsteroidal antiinflammatory drugs

Select the option which is not correct with respect to enzyme action. (a) Substrate binds with enzyme at its active site. (b) Addition of lot of succinate does not reverse the inhibition of succinic dehydrogenase by malonate. (c) A non-competitive inhibitor binds the enzyme at a site distinct from that which binds the substrate. (d) Malonate is a competitive inhibitor of succinic dehydrogenase.

Description : Select the option which is not correct with respect to enzyme action. (a) Substrate binds with enzyme at its active site. (b) Addition of lot of succinate does not reverse the inhibition ... from that which binds the substrate. (d) Malonate is a competitive inhibitor of succinic dehydrogenase.

Last Answer : (b) Addition of lot of succinate does not reverse the inhibition of succinic dehydrogenase by malonate.

The high virus selectivity of acyclovir is due to: A. Its preferential uptake by virus infected cells B. Need of virus specific enzyme for its conversion to the active metabolite C. Its action on virus directed reverse transcriptase which does not occur in noninfected cells D. Both ‘A’ and ‘B’ are correct

Description : The high virus selectivity of acyclovir is due to: A. Its preferential uptake by virus infected cells B. Need of virus specific enzyme for its conversion to the active metabolite C. Its action on ... reverse transcriptase which does not occur in noninfected cells D. Both A' and B' are correct

Last Answer : D. Both ‘A’ and ‘B’ are correct

Clinically, the angiotensin antagonists share the following features of angiotensin converting enzyme inhibitors except: A. Antihypertensive efficacy B. Potential to reverse left ventricular hypertrophy C. Lack of effect on carbohydrate tolerance D. Potential to induce cough in susceptible individuals

Description : Clinically, the angiotensin antagonists share the following features of angiotensin converting enzyme inhibitors except: A. Antihypertensive efficacy B. Potential to reverse left ventricular hypertrophy ... of effect on carbohydrate tolerance D. Potential to induce cough in susceptible individuals

Last Answer : D. Potential to induce cough in susceptible individuals

Which one of the following is incorrect about the characteristics of protobionts (coacervates and microspheres) as envisaged in the abiogenic origin of life? (a) They were partially isolated from the surroundings. (b) They could maintain an internal environment. (c) They were able to reproduce. (d) They could separate combinations of molecules from the surroundings.

Description : Which one of the following is incorrect about the characteristics of protobionts (coacervates and microspheres) as envisaged in the abiogenic origin of life? (a) They were partially isolated from ... were able to reproduce. (d) They could separate combinations of molecules from the surroundings.

Last Answer : (c) They were able to reproduce

Two plants can be conclusively said to belong to the same species if they (a) have more than 90 percent similar genes (b) look similar and possess identical secondary metabolites (c) have same number of chromosomes (d) can reproduce freely with each other and form seeds.

Description : Two plants can be conclusively said to belong to the same species if they (a) have more than 90 percent similar genes (b) look similar and possess identical secondary metabolites (c) have same number of chromosomes (d) can reproduce freely with each other and form seeds.

Last Answer : (d) can reproduce freely with each other and form seeds

Adult human RBCs are enucleate. Which of the following statement(s) is/are most appropriate explanation for this feature? (1) They do not need to reproduce. (2) They are somatic cells. (3) They do not metabolise. (4) All their internal space is available for oxygen transport. (a) Only (1) (b) (1), (3) and (4) (c) (2) and (3) (d) Only (4)

Description : Adult human RBCs are enucleate. Which of the following statement(s) is/are most appropriate explanation for this feature? (1) They do not need to reproduce. (2) They are somatic cells. (3) They do not metabolise. (4) All their internal ... Only (1) (b) (1), (3) and (4) (c) (2) and (3) (d) Only (4)

Last Answer : (d) Only (4)

Fungi in the division Deuteromycota are characterized by the fact that A- they only reproduce sexually B- they form sexual spores called deuterospores C- they are incapable of sexual reproduction D- a method of sexual reproduction has not been identified

Description : Fungi in the division Deuteromycota are characterized by the fact that A- they only reproduce sexually B- they form sexual spores called deuterospores C- they are incapable of sexual reproduction D- a method of sexual reproduction has not been identified

Last Answer : a method of sexual reproduction has not been identified

Adult human RBCs are enucleated. Which of the following statement(s) is/are most appropriate explanation for this feature ? (a) They do not need to reproduce (b) They are somatic cells (c) They do not metabolize (d) All their internal space is available for oxygen transport (1) only (a) (2) (a), (c) and (d) (3) (b) and (c) (4) only (d)

Description : Adult human RBCs are enucleated. Which of the following statement(s) is/are most appropriate explanation for this feature ? (a) They do not need to reproduce (b) They are somatic cells (c) They do not metabolize (d) All their internal space ... (a) (2) (a), (c) and (d) (3) (b) and (c) (4) only (d)

Last Answer : (4) only (d)

(a) What is the role of HCl in our stomach ? (b) What is emulsification of fats ? (c) Which protein digesting enzyme is present in pancreatic juice ? -Biology

Description : (a) What is the role of HCl in our stomach ? (b) What is emulsification of fats ? (c) Which protein digesting enzyme is present in pancreatic juice ? -Biology

Last Answer : (a)(i) It sterilises food by killing pathogens and other microbes. (ii) It has a pH of 2, which is perfect for entyaus such as pepsin to break down proteins as effectively as possible. ( ... as emulsification. (c) Trypsin is the enzyme secreted by the pancreas which aids in digestion of proteins.

What is the role of NADP reductase enzyme in proton gradient development? -Biology

Description : What is the role of NADP reductase enzyme in proton gradient development? -Biology

Last Answer : answer:

What is the role of the enzyme DNA primase?

Description : What is the role of the enzyme DNA primase?

Last Answer : Primase is an enzyme that synthesizes short RNA sequences called primers which serve as a starting point for DNA synthesis. Since primase produces RNA molecules, the enzyme is a type of RNA ... strand of nucleotides. Therefore, primase serves to prime and lay a foundation for DNA synthesis.

Platelets contain an enzyme which has important role in clotting in blood. This enzyme is known as (A) Cholinesterase (B) Transaminase (C) Decarboxylase (D) Thrombokinase

Description : Platelets contain an enzyme which has important role in clotting in blood. This enzyme is known as (A) Cholinesterase (B) Transaminase (C) Decarboxylase (D) Thrombokinase

Last Answer : Answer : D

What role does enzyme pepsin play? (1) It converts fats into acids (2) If converts fats into glycerol (3) It converts proteins into peptones (4) It converts starch into sugar

Description : What role does enzyme pepsin play? (1) It converts fats into acids (2) If converts fats into glycerol (3) It converts proteins into peptones (4) It converts starch into sugar

Last Answer : (3) It converts proteins into peptones Explanation: Pepsin is an endopeptidase that breaks down proteins into peptone and polypeptides. If is produced in the stomach and is one of the main digestive enzymes.

Which one of the following statements about cytochrome P450 is wrong? (a) It is a coloured cell. (b) It is an enzyme involved in oxidation reactions. (c) It has an important role in metabolism. (d) It contains iron

Description : Which one of the following statements about cytochrome P450 is wrong? (a) It is a coloured cell. (b) It is an enzyme involved in oxidation reactions. (c) It has an important role in metabolism. (d) It contains iron

Last Answer : (a) It is a coloured cell.

What is the role of NAD+ in cellular respiration? (a) It functions as an enzyme. (b) It functions as an electron carrier. (c) It is a nucleotide source for ATP synthesis. (d) It is the final electron acceptor for anaerobic respiration.

Description : What is the role of NAD+ in cellular respiration? (a) It functions as an enzyme. (b) It functions as an electron carrier. (c) It is a nucleotide source for ATP synthesis. (d) It is the final electron acceptor for anaerobic respiration.

Last Answer : c) It is a nucleotide source for ATP synthesis.

Role of an enzyme in reactions is to/as (a) decrease activation energy (b) increase activation energy (c) inorganic catalyst (d) none of the above.

Description : Role of an enzyme in reactions is to/as (a) decrease activation energy (b) increase activation energy (c) inorganic catalyst (d) none of the above.

Last Answer : (a) decrease activation energy

Potentiation of bradykinin appears to play a role in the following effects of angiotensin converting enzyme inhibitors except: A. Fall in BP in the short term B. Fall in BP in the long term C. Cough in susceptible individuals D. Angioedema in susceptible individuals

Description : Potentiation of bradykinin appears to play a role in the following effects of angiotensin converting enzyme inhibitors except: A. Fall in BP in the short term B. Fall in BP in the long term C. Cough in susceptible individuals D. Angioedema in susceptible individuals

Last Answer : B. Fall in BP in the long term

How do Spirogyra and Mucor reproduce asexually ?

Description : How do Spirogyra and Mucor reproduce asexually ?

Last Answer : Spirogyra and Mucor are both organisms that reproduce asexually through fragmentation. Spirogyra reproduces asexually by fragmentation, which occurs when the filament breaks into individual cells that can ... , and in this way, Mucor can reproduce asexually through fragmentation of the mycelium.

How do small mammals reproduce in the ISS (International Space Station)?

Description : How do small mammals reproduce in the ISS (International Space Station)?

Last Answer : Artificial insemination. For humans, a lot of bungee cords. Seriously, there have not been any known experiments.

Who should reproduce?

Description : Who should reproduce?

Last Answer : If you voted for Trump .. Feel free to fill in the blank.