Life Sciences

Monoclonal antibodies are lab-made proteins that target specific antigens and can be used to treat viral infections like Nipah virus.

* I. Man-made proteins – Created by cloning a single immune cell type. * II. Bind to specific antigens – Help stimulate or guide immune response. * III. Used in viral infections – Applied in treating infections like Nipah virus.

All three statements are correct.

Viruses can survive in oceans, infect bacteria, and alter host cell transcription.

Statement I: False. Viruses can survive in ocean waters, and marine viruses are highly abundant.

Statement II: False. Viruses can infect bacteria; for example, bacteriophages specifically infect bacteria.

Statement III: False. Viruses can alter host transcription and modify host gene expression.

None of the statements are correct.

All four statements are correct.

* Medicinal mushrooms: Certain mushroom species have been used in traditional medicine for centuries and are still being studied for their potential health benefits. Examples include reishi mushrooms (Ganoderma lucidum) for immune system support and lion's mane mushrooms (Hericium erinaceus) for cognitive function.

* Psychoactive mushrooms: Some mushrooms contain psilocybin, a naturally occurring psychoactive compound that can induce hallucinations. These are commonly referred to as "magic mushrooms" or psilocybin mushrooms.

* Insecticidal mushrooms: Some mushroom species produce natural compounds that can repel or even kill insects. These compounds act as a defence mechanism for the mushrooms against insect pests.

* Bioluminescent mushrooms: A less common but fascinating property, bioluminescence, is found in some mushroom species. These mushrooms can produce and emit light, creating a glowing effect.

Statement 1 is Correct: Hyperthermophiles are microorganisms that can thrive in temperatures above 100°C (the boiling point of water). For example, *Pyrolobus fumarii* is an archaeon that lives in hydrothermal vents at temperatures up to 113°C.

Statement 2 is Correct: Psychrophiles (or cryophiles) are extremophilic organisms capable of growth and reproduction in cold temperatures, often ranging from -20°C to +10°C, which is below the freezing point of water (0°C).

Statement 3 is Correct: Acidophiles are microorganisms that thrive in highly acidic environments. Extreme acidophiles, such as *Picrophilus oshimae*, can grow optimally at pH levels below 3, with some species surviving at pH levels near 0.

The Wolbachia method is a biological method that utilises the Wolbachia bacteria to control the spread of mosquito-borne diseases, particularly dengue fever.

* Wolbachia naturally infects some insect species, but not Aedes aegypti mosquitoes, the primary vector for dengue fever transmission. Scientists introduce Wolbachia into Aedes aegypti populations. Wolbachia reduces the ability of these mosquitoes to transmit dengue virus.

* As Wolbachia spreads through the mosquito population, it can significantly reduce the incidence of dengue fever.

* This method offers a natural and sustainable approach to controlling dengue fever, a major public health concern in tropical and subtropical regions.

B cells and T cells are both key components of the human immune system, which defend the body against harmful invaders like viruses, bacteria, and parasites.

B cells produce antibodies that can specifically target and neutralize pathogens.

T cells help orchestrate the immune response by directly attacking infected cells or by stimulating other immune cells.


Statement 1 is incorrect: Adenoviruses have double-stranded DNA genomes. Retroviruses have single-stranded RNA genomes.

Statement 2 is correct: Adenoviruses are one of the many viruses that can cause the common cold. AIDS (Acquired Immunodeficiency Syndrome) is caused by the Human Immunodeficiency Virus (HIV), which is a type of retrovirus.

Fern: * Ferns typically require soil and moisture to grow, as they rely on water-conducting tissues and need a substrate to anchor their roots.

Lichen: * Lichens are a symbiotic association between a fungus and an algae or cyanobacteria. * Lichens are well-adapted to survive on surfaces without soil, such as rocks, tree bark, and even bare ground, as they can obtain their nutrients and moisture directly from the air and precipitation. * Lichens are sensitive to airborne pollutants, such as sulfur dioxide (SO2), nitrogen oxides (NOx), ozone (O3), and heavy metals (like lead and mercury). Sulfur dioxide, for instance, causes chlorosis (yellowing) and necrosis (cell death) in lichen thalli. This sensitivity makes lichens an effective indicator of air quality.

Moss: * Mosses are non-vascular plants that can grow on surfaces without soil, such as rocks, tree trunks, and even roofs. * Mosses have specialised structures that allow them to absorb water and nutrients directly from the environment.

Mushrooms: * Mushrooms are the reproductive structures of fungi, and they typically require a substrate, such as decaying organic matter, to grow. Mushrooms are not able to directly survive on a surface without soil or a nutrient-rich medium.

Therefore, among the given options, lichens and mosses are the most likely to be found surviving on a surface without soil in the natural environment.

* The term 'ACE2' is talked about in the context of the spread of viral diseases, particularly COVID-19.

* ACE2 stands for Angiotensin-Converting Enzyme 2. It's a protein found on the surface of many cell types in the human body, including those in the lungs, heart, kidneys, and intestines.

* Here's why ACE2 is significant:

* Receptor for SARS-CoV-2: The spike protein on the surface of the SARS-CoV-2 virus, the virus that causes COVID-19, binds to the ACE2 receptor in human cells. This binding is a critical step in the process of how the virus infects cells. * Multiple organ infection: Since ACE2 is expressed in various organs, it provides the virus with multiple potential entry points. This can contribute to the multi-organ complications sometimes associated with COVID-19. * Focus of research: Understanding the interaction between the virus and ACE2 is a major area of research for scientists developing vaccines and treatments for COVID-19.



Statement 1 is correct. Plant cells have rigid cell walls made of cellulose, a complex carbohydrate, which animal cells lack. Animal cells rely on a plasma membrane for structure and protection.

Statement 2 is incorrect. Both plant and animal cells have a plasma membrane, a phospholipid bilayer that controls what enters and leaves the cell. It's a fundamental component for all cells.

Statement 3 is correct. Mature plant cells typically have a single, large central vacuole that stores water, nutrients, and waste products. Animal cells can have vacuoles, but they are usually smaller and more numerous.

Statement 1 is correct. Pneumococcal Conjugate Vaccines (PCVs) are effective in preventing several serious diseases caused by Streptococcus pneumoniae bacteria. This includes pneumonia, meningitis (inflammation of the meninges surrounding the brain and spinal cord), and sepsis (a life-threatening blood infection).

Statement 2 is also correct. The growing prevalence of antibiotic-resistant strains of Streptococcus pneumoniae is a major concern. PCV vaccination helps reduce dependence on antibiotics, particularly for these resistant strains. This lowers the risk of antibiotic overuse and emergence of further resistance.

Statement 3 is incorrect. While most people experience no serious side effects with PCV vaccines, there can be mild reactions like redness, swelling, or soreness at the injection site. Serious allergic reactions are rare.

Statement 1 is incorrect. While genetic factors can contribute to susceptibility to infections, they are not directly related to the occurrence of multi-drug resistance in microbial pathogens.

Statement 2 is correct. Incorrect use of antibiotics, including taking incorrect doses or not completing the full course of treatment, can contribute to the development of drug resistance in microbial pathogens.

Statement 3 is correct. The widespread use of antibiotics in livestock farming can lead to the development of drug-resistant pathogens that can affect both animals and humans.

Statement 4 is incorrect. While individuals with chronic diseases may be more susceptible to infections, this factor is not directly related to the occurrence of multi-drug resistance in microbial pathogens.

Option A is correct. Both Hepatitis B virus and HIV (Human Immunodeficiency Virus) can be transmitted through blood-to-blood contact, sexual contact, and from mother to child during childbirth.

Option B is incorrect. Unlike Hepatitis C, there is a vaccine available for Hepatitis B. The Hepatitis B vaccine is highly effective in preventing Hepatitis B virus infection.

Option C is correct. According to global health statistics, the number of people infected with Hepatitis B and C viruses combined is indeed several times more than those infected with HIV.

Option D is correct. Many individuals infected with Hepatitis B and C viruses may not show any symptoms for years or even decades. This is known as chronic hepatitis, and it can lead to severe liver damage if left untreated.


All of the listed factors - birds, dust blowing, rain, and wind blowing - can contribute to the spread of plant diseases

Statement 1 is correct: Birds can act as vectors, carrying and spreading plant pathogens from one location to another through their feathers, feet, or droppings.

Statement 2 is correct: Dust and soil particles blown by the wind can carry and spread plant diseases, especially fungal spores and bacterial cells.

Statement 3 is correct: Rain can splash and disperse plant pathogens, such as fungi and bacteria, from the soil or infected plant parts to uninfected plants.

Statement 4 is correct: Wind can transport and spread airborne plant pathogens, such as fungal spores and bacterial cells, over long distances.

Statement 1 is correct: Viruses that infect bacteria are known as bacteriophages or phages. These viruses use bacterial cells as hosts to replicate and propagate.

Statement 2 is correct: Certain viruses, called mycoviruses, can infect and replicate within fungal cells, using them as hosts.

Statement 3 is correct: Viruses that infect plants are known as plant viruses. They can hijack the cellular machinery of plant cells to replicate and spread within the plant.

Hence, option D is the correct answer.

Influenza (H1N1) virus is a subtype of influenza A virus that was the most common cause of human influenza (flu) in 2009 and is associated with the 1918 outbreak known as the Spanish Flu. It is an orthomyxovirus that contains the glycoproteins haemagglutinin and neuraminidase. For this reason, they are described as H1N1, H1N2 etc., depending on the type of H or N antigens they express with metabolic synergy.

- Haemagglutinin causes red blood cells to clump together and binds the virus to the infected cell. - Neuraminidase is a type of glycoside hydrolase enzyme which helps to move the virus particles through the infected cell and assist in budding from the host cells.

In June 2009, the World Health Organization (WHO) declared the new strain of swine-origin H1N1 as a pandemic. This strain is often called swine flu by the public media.

Guinea, Sierra Leone, and Liberia were in the news for the outbreak of the Ebola virus.

The most widespread outbreak of the Ebola virus disease began in 2013 and continued until 2016, causing major loss of life and socio-economic disruption in the West African region, mainly in the countries of Guinea, Liberia, and Sierra Leone. The first cases were recorded in Guinea in December 2013. Later, the disease spread to neighboring Liberia and Sierra Leone.

Therefore, option B is the correct answer.

Hibernation is a state of decreased physiological activity and lowered body temperature that certain animals, such as bats and bears, undergo during the winter months to conserve energy and survive periods of limited food availability.

Statement 1 is correct: Bats, especially those living in temperate regions, often enter a state of hibernation during the colder months when their food sources (insects) are scarce.

Statement 2 is correct: Bears, including the brown bear, black bear, and polar bear, are well-known hibernators.

Statement 3 is correct: Many rodent species, including groundhogs and chipmunks, are true hibernators.

Thus, all three statements are correct.

Mites, scorpions, and spiders are all classified within the class Arachnida.

Crabs, although arthropods like the others belong to the class Crustacea.

Therefore, the crab is the odd one out due to its different taxonomic classification.

Statement 1 is incorrect: The Government introduced the Pentavalent vaccine, which also fights against Diphtheria. This implies that Diphtheria is still prevalent.

Statement 2 is incorrect: Chickenpox is still widespread among the population.

Statement 3 is correct: Smallpox has been eradicated from India. India declared itself free of smallpox in 1979.

Statement 1 is correct: Viruses do not have metabolic machinery of their own. They lack enzymes needed for ATP generation and therefore must depend entirely on a host cell.

Statement 2 is incorrect: Viruses cannot be grown on artificial or synthetic media. They need living host cells (bacteria, plants, animals, or cell cultures) to replicate.

Statement 3 is incorrect: Transmission can occur through: - Physical contact, respiratory droplets - Contaminated water/food - Airborne routes - Fomites (inanimate objects) - Biological vectors (mosquitoes, ticks, etc.)

Hence, vectors are not the only mode of transmission.

* Chikungunya is a mosquito-borne viral disease that cannot be spread through tattooing.

* Hepatitis B is a liver infection that can lead to liver failure and cancer. It's spread through contact with the blood, open sores, or body fluids of an infected person.

* HIV is a virus that destroys the white blood cells responsible for fighting infections. It can result in AIDS, the final stage of infection. It spreads mainly through unprotected sex, sharing drug needles, or contact with infected blood.

* Bacteria can be cultured and grown in various artificial culture media, such as nutrient broth, agar plates, or other specific media formulations. Bacteria can metabolize and utilize the nutrients provided in these synthetic culture media to grow and reproduce.

* Fungi can also be cultured in artificial media, such as potato dextrose agar, Sabouraud dextrose agar, or other specialized fungal growth media. Fungi can utilize the organic compounds and nutrients present in these synthetic media to support their growth and development.

* Viruses, on the other hand, are obligate intracellular parasites and cannot be directly cultured in artificial or synthetic media. Viruses require living host cells to replicate and propagate, as they lack the necessary machinery for autonomous growth and reproduction.

Statement 1 is correct: The Zika virus is primarily transmitted by the Aedes aegypti mosquito, which is the same mosquito that transmits the dengue virus in tropical and subtropical regions.


Statement 2 is correct: While Zika virus is primarily transmitted through mosquito bites, the virus can also be transmitted from person to person through sexual contact.

Therefore, both the statements 1 and 2 are correct.

* Cnidarians: Many cnidarian species, such as corals, develop symbiotic relationships with single-celled algae called zooxanthellae. This symbiosis is crucial for the survival and growth of coral reefs.

* Fungi: Fungi are known to form various symbiotic relationships with other organisms, including * Mycorrhizal associations with plant roots, where the fungus helps the plant absorb nutrients in exchange for carbohydrates. * Lichens are a symbiotic relationship between a fungus and an algae or cyanobacteria.

* Protozoa: Some protozoa living in the digestive tracts of termites and ruminant animals, helping them break down cellulose.

Therefore, all three groups - cnidarians, fungi, and protozoa - have species that can form symbiotic relationships with other organisms.

Among marine creatures, the sea cow and sea lion are mammals, while the sea horse is a fish.

1. Sea Cow: The sea cow, a herbivorous marine mammal, resides in the Indian and Pacific Oceans, growing to 3m and weighing around 600kg. Sadly, it's vulnerable due to habitat degradation and hunting.

2. Sea Horse: The sea horse, a carnivorous marine fish, is found in shallow tropical waters. It grows to 35cm, weighs around 200g, and is vulnerable due to habitat damage and fishing.

3. Sea Lion: The sea lion, a carnivorous marine mammal, breeds on Pacific beaches. It grows to 2.5m, weighs around 350kg, and is Endangered.