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Doctors Medicines MCQs Q&A

Which of the following statements is/are incorrect? 1. Viruses lack the enzymes necessary for the generation of energy. 2. Viruses can not be cultured in any synthetic medium. 3. Viruses are transmitted from one organism to another by biological vectors only. Select the correct answer using the codes given below.

Which of the following statements is/are incorrect? 1. Viruses lack the enzymes necessary for the generation of energy. 2. Viruses can not be cultured in any synthetic medium. 3. Viruses are transmitted from one organism to another by biological vectors only. Select the correct answer using the codes given below. Correct Answer 3 only

The correct answer is 3 only.

Key Points

  • Viruses
    • Viruses have no metabolic enzymes and cannot generate their own energy. Hence 1 statement is correct.
    • Viruses require a growth medium containing living cells, therefore, cannot be cultured in any synthetic medium. Hence 2 statement is correct.
    • Viruses are transmitted from one organism to another not only by biological vectors but also by mechanical vectors. Hence 3 statement is incorrect.
    • Mechanical vector like an arthropod vector which transmits an infective organism from one host to another but it is not essential to the life of cycle of the parasite.
    • Viruses did not find a place in classification since they are not truly living if we understand living as those organisms that have a cell structure.
    • The viruses are non-cellular organisms that are characterized by having an inert crystalline structure outside the living cell.
    • Viruses are obligate parasites. Once they infect a cell, they take over the machinery of the host cell to replicate themselves, killing the host.
    • The name virus that means venom or poisonous fluid was given by Pasteur.
    • In addition to proteins, viruses also contain genetic material, which could be either RNA or DNA.
    • No virus contains both RNA & DNA.
  • In general,
    • Viruses that infect plants have single-stranded RNA &
    • Viruses that infect animals have either single or double-stranded RNA or double-stranded DNA
    • Bacteriophages (viruses that infect bacteria) are usually double-stranded DNA viruses.
  • The protein coat called capsid made of small subunits called capsomeres protects the nucleic acid.
  • These capsomeres are arranged in helical or polyhedral geometric forms.

Related Questions

Which of the following statements is/are incorrect? 1. Viruses lack the enzymes necessary for the generation of energy. 2. Viruses can be cultured in any synthetic medium. 3. Viruses are transmitted from one organism to another by biological vectors only. Select the correct answer using the codes given below.
Which of the following statements is/are correct? 1. Viruses lack enzymes necessary for the generation of energy. 2. Viruses can be cultured in any synthetic medium. 3. Viruses are transmitted from one organism to another by biological vectors only. Select the correct answer using the codes given below. 
Read the following passage and answer the item that follows. Your answers to this item should be based on the passage only. Many farmers use synthetic pesticides to kill infesting insects. The consumption of pesticides in some of the developed countries is touching 3000 grams/hectare. Unfortunately, there are reports that these compounds possess inherent toxicities that endanger the health of the farm operators, consumers and the environment. Synthetic pesticides are generally persistent in environment. Entering in food chain they destroy the microbial diversity and cause ecological imbalance. Their indiscriminate use has resulted in development of resistance among insects to insecticides, upsetting of balance in nature and resources of treated populations. Natural pest control using the botanical pesticides is safer to the user and the environment because they break down into harmless compounds within hours or days in the presence of sunlight. Plants with pesticidal properties have been in nature for millions of years without any ill or adverse effects on the ecosystem. They are easily decomposed by many microbes common in most soils. They help in the maintenance of biological diversity of predators and human health hazards. Botanical pesticides formulated from plants are biodegradable and their use in crop protection is a practical sustainable alternative. On the basis of the above passage, the following assumptions have been made: 1. Synthetic pesticides should never be used in modern agriculture. 2. One of the aims of sustainable agriculture is to ensure minimal ecological imbalance. 3. Botanical pesticides are more effective as compared to synthetic pesticides. Which of the assumptions given above is/are correct?
Read the following passage and answer the item that follows. Your answers to this item should be based on the passage only. Many farmers use synthetic pesticides to kill infesting insects. The consumption of pesticides in some of the developed countries is touching 3000 grams/hectare. Unfortunately, there are reports that these compounds possess inherent toxicities that endanger the health of the farm operators, consumers and the environment. Synthetic pesticides are generally persistent in environment. Entering in food chain they destroy the microbial diversity and cause ecological imbalance. Their indiscriminate use has resulted in development of resistance among insects to insecticides, upsetting of balance in nature and resources of treated populations. Natural pest control using the botanical pesticides is safer to the user and the environment because they break down into harmless compounds within hours or days in the presence of sunlight. Plants with pesticidal properties have been in nature for millions of years without any ill or adverse effects on the ecosystem. They are easily decomposed by many microbes common in most soils. They help in the maintenance of biological diversity of predators and human health hazards. Botanical pesticides formulated from plants are biodegradable and their use in crop protection is a practical sustainable alternative. Which of the following statements is/are correct regarding biopesticides? 1. They are not hazardous to human health. 2. They are persistent in environment. 3. They are essential to maintain the biodiversity of any ecosystem. Select the correct answer using the code given below.
Which of the following statements refers to the process of 'parthenogenesis'? 1. It is a natural form of asexual reproduction in which the growth and development of embryos occur without fertilisation. 2. It is a mode of reproduction in which a male organism's sperm fertilizes a female organism's egg outside of the female's body. 3. It is a mode of reproduction in which a male organism's sperm fertilizes a female organism's egg inside of the female's body  Select the correct answer using the codes given below.
With reference to the usefulness of the by-products of sugar industry, Which of the following statements is/are correct 1. Bagasse can be used as biomass fuel for the generation of energy. 2. Molasses can be used as one of the feedstocks for the production of synthetic chemical fertilizers. 3. Molasses can be used for the production of ethanol. Select the correct answer using the codes given below:
There are two medium L1 and L2 of refractive index n1 and n2 respectively (n2  > n1 > 1). In which of the following condition the total internal reflection may occur: a) When the light travel from medium L1 to medium L2. b) When the light travels from medium L2 to medium L1. c) When the light travel from medium L1 to air. d) When the light travels from air to medium L2. Which of the following statement is correct?
One bacterium splits into eight bacteria of the next generation. But due to environment, only 50% of one generation can produced the next generation. If the seventh generation number is 4096 million, what is the number in first generation?
Consider the following statements regarding the laws of evolution from Lamarck's thesis and choose the correct answer:
1. The internal forces of life tend to increase the size of an organism not only as a whole but in every part as well
2. Each organ or part is the outcome of the new movement which in turn is initiated by a new and continuous need or want
3. All that has been acquired by an individual organism during its lifetime is transmitted by heredity to its offsprings in the next generation
Biomass gasification is considered to be one of the sustainable solutions to the power crisis in India, In this context, which of the following statements is/are correct? 1. Coconut shells, groundnut shells and rice husk can be used in biomass gasification. 2. The combustible gases generated from biomass gasification consist of hydrogen and carbon dioxide only. 3. The combustible gases generated from biomass gasification can be used for direct heat generation but not in internal combustion engines. Select the correct answer using the codes given below: