NEET-PG 2012 Practice Questions

Q: Which oil has the highest concentration of linolenic acid?

Soyabean oil. ***Soyabean oil*** - **Soyabean oil** contains approximately **7-10% linolenic acid (C18:3)**, an omega-3 fatty acid. - Among the given options, it has the **highest concentration** of this essential fatty acid. - **Linolenic acid** is crucial for **heart health** and **reducing inflammation**. *Coconut oil* - **Coconut oil** is primarily composed of **saturated fatty acids**, notably **lauric acid (C12:0)**. - It contains **negligible amounts** of **linolenic acid** (<0.5%). *Groundnut oil* - **Groundnut oil** (peanut oil) is rich in **oleic acid (C18:1)** and **linoleic acid (C18:2)**. - Its concentration of **linolenic acid** is very low (**~0.5-1%**), much lower than soyabean oil. *Safflower oil* - **Safflower oil** is known for its high content of **linoleic acid (C18:2)**, an omega-6 fatty acid. - It contains **minimal amounts** of **linolenic acid** (<1%).

Q: Effect of environment on genes is called?

Epigenetics. ***Epigenetics*** - **Epigenetics** refers to heritable changes in **gene expression** that do not involve alterations to the underlying **DNA sequence**. - These changes are often influenced by **environmental factors**, such as diet, stress, and exposure to toxins, which can affect how genes are turned on or off. *Positive Eugenics* - **Positive eugenics** aims to improve the human population by encouraging the reproduction of individuals deemed to have "desirable" traits. - This concept is ethically controversial and focuses on directed breeding rather than environmental gene influence. *Negative Eugenics* - **Negative eugenics** aims to reduce the prevalence of "undesirable" traits in the human population by discouraging or preventing the reproduction of individuals deemed to possess them. - Like positive eugenics, this is a highly controversial concept focused on limiting reproduction based on perceived genetic quality. *Euthenics* - **Euthenics** is a movement focused on improving human well-being and development by improving living conditions and the environment. - While it acknowledges the impact of the environment, it focuses on societal and lifestyle improvements rather than the direct molecular changes in gene expression.

Q: In winter, water vapours and pollutants come to lie in the lowermost layer of atmosphere by -?

Temperature inversion. ***Temperature inversion*** - **Temperature inversion** is an atmospheric phenomenon where a layer of cool air at the surface is trapped beneath a layer of warmer air. - This stable condition prevents the normal vertical mixing of air, causing pollutants and water vapors to accumulate in the lowest layer of the atmosphere, leading to conditions like **smog** and **fog**. *Acid rain* - **Acid rain** refers to precipitation (rain, snow, fog, etc.) that contains elevated levels of nitric and sulfuric acids. - It results from the emissions of sulfur dioxide and nitrogen oxides into the atmosphere, which then react with water, oxygen, and other chemicals, rather than directly causing pollutants to lie in the lowermost layer. *Greenhouse effect* - The **greenhouse effect** is a natural process where certain gases in Earth's atmosphere trap heat, warming the planet. - While it affects global temperatures, it does not directly explain the specific phenomenon of pollutants and water vapors being trapped in the lowermost atmospheric layer during winter due to atmospheric stability. *None of the options* - Since **temperature inversion** accurately describes the mechanism responsible for trapping pollutants and water vapors in the lowermost atmospheric layer, this option is incorrect.

Q: The odour of cyanide is similar to?

Bitter almond. ***Bitter almond*** - The classic description of **cyanide odor** is that of **bitter almonds**. This specific scent is a key indicator during forensic investigations or in cases of suspected poisoning. - However, not everyone can detect this smell due to a **genetic trait** that affects the ability to perceive it. *Rotten egg* - A **rotten egg** odor is characteristic of **hydrogen sulfide (H2S)**, a highly toxic gas. - This gas is often produced by the decomposition of organic matter and does not indicate cyanide exposure. *Fish* - A **fishy odor** is typically associated with compounds like **amines**, such as **trimethylamine**, which are found in decomposing fish or certain medical conditions like **trimethylaminuria**. - This smell is distinct from the bitter almond scent of cyanide. *Fruity* - A **fruity odor** can be associated with various substances, including **ketones** in conditions like **diabetic ketoacidosis** or certain **volatile organic compounds**. - This scent is not characteristic of cyanide poisoning.

Q: Who discovered the malarial parasite?

Charles Louis Alphonse Laveran. ***Charles Louis Alphonse Laveran*** - **Charles Louis Alphonse Laveran** was a French physician who, in **1880**, observed parasites in the blood of a malaria patient. - He was awarded the **Nobel Prize in Physiology or Medicine in 1907** for his discovery of the role of protozoa in causing diseases, specifically recognizing the malarial parasite. *Ronald Ross* - **Ronald Ross** was a British physician who, in **1897**, demonstrated that **malaria is transmitted by mosquitoes**. - While he elucidated the **transmission cycle**, it was Laveran who first identified the parasite itself in human blood. - He received the **Nobel Prize in 1902** for this work. *Paul Muller* - **Paul Muller** was a Swiss chemist who was awarded the **Nobel Prize in Physiology or Medicine in 1948** for his discovery of the insecticidal properties of **DDT (dichlorodiphenyltrichloroethane)**. - His work was significant in combating insect-borne diseases like malaria, but he was not involved in the discovery of the malarial parasite. *Pampania* - This name does not correspond to any recognized figure in the discovery of the malarial parasite or its transmission. - This is a distractor option in the original examination question.

Q: Largest intestinal protozoan is?

Balantidium coli. ***Balantidium coli*** - *Balantidium coli* is the **largest protozoan parasite** known to infect humans, specifically found in the intestines. - It causes **balantidiasis**, an intestinal infection, and is notable for its ciliated trophozoite stage. *E. coli* - *E. coli* is a **bacterium**, not a protozoan. - While it is a common inhabitant of the intestines, it is significantly smaller than parasitic protozoa. *Giardia* - *Giardia lamblia* (or *intestinalis*) is a **flagellate protozoan** that causes giardiasis. - Though an intestinal parasite, it is considerably smaller than *Balantidium coli*. *T. gondii* - *Toxoplasma gondii* is an **intracellular protozoan parasite** known for causing toxoplasmosis. - It is much smaller than *Balantidium coli* and primarily infects cells, not existing as a large free-living form in the intestine.

Q: Which of the following statements about corneal dystrophy is true?

It is typically bilateral.. ***It is typically bilateral.*** - **Corneal dystrophies** are inherited genetic disorders that usually affect both eyes symmetrically. - This bilateral presentation is a key characteristic distinguishing them from other corneal conditions. *It is caused by inflammation.* - **Corneal dystrophies** are primarily genetic and degenerative, not inflammatory. - While inflammation can cause corneal damage (e.g., keratitis), it is not the underlying cause of dystrophy. *It involves neovascularization.* - **Neovascularization** (growth of new blood vessels) is typically a response to chronic inflammation, hypoxia, or infection in the cornea. - It is generally not a feature of primary corneal dystrophies, which are characterized by abnormal deposits or structural changes within the corneal layers. *It is usually unilateral.* - As inherited genetic conditions, **corneal dystrophies** almost always affect both eyes. - Unilateral involvement would suggest a different etiology, such as trauma, infection, or a localized acquired condition.

Q: What is the treatment of choice for amblyopia?

Occlusion therapy. ***Occlusion therapy*** - **Occlusion therapy** involves patching the stronger eye to force the weaker, amblyopic eye to work harder, thereby strengthening its neural connections. - This treatment is most effective when initiated during the **critical period of visual development** in childhood. *Corrective spectacles* - While essential for addressing **refractive errors** that may contribute to amblyopia, spectacles alone are often insufficient to resolve the amblyopia. - Spectacles primarily optimize the image quality on the retina, but don't directly address the **cortical suppression** of the amblyopic eye. *Surgical intervention* - **Surgical intervention** is typically reserved for correcting structural issues like **strabismus** (misalignment of the eyes) that contribute to amblyopia. - Surgery for strabismus aims to align the eyes, which can then be followed by occlusion therapy or other treatments to address the functional amblyopia. *Convergent exercises for vision therapy* - **Vision therapy exercises**, including convergent exercises, may be used as an adjunct to occlusion therapy or in cases of **convergence insufficiency**. - However, they are not the primary or solitary treatment of choice for amblyopia, which requires direct stimulation of the amblyopic eye.

Q: Guanethidine is used in the treatment of which of the following conditions?

Thyrotoxic ophthalmopathy. ***Thyrotoxic ophthalmopathy*** - Guanethidine is an **adrenergic neuron blocker** that can be used topically to reduce the sympathetic overactivity in the eye associated with thyrotoxicosis. - It helps alleviate symptoms like **retraction of the eyelids** and proptosis by blocking norepinephrine release from sympathetic nerve endings. *Ptosis* - **Ptosis** is primarily caused by weakness of the levator palpebrae superioris muscle or oculomotor nerve dysfunction, not sympathetic overactivity. - Guanethidine would not address the underlying muscular or neurologic deficit causing ptosis. *Bell's palsy* - **Bell's palsy** involves sudden, temporary weakness or paralysis of the muscles on one side of the face due to a dysfunction of the facial nerve. - Treatment typically involves corticosteroids and antivirals; guanethidine has no role in its management. *Horner's syndrome* - **Horner's syndrome** is characterized by miosis, ptosis, and anhidrosis, resulting from damage to the sympathetic nerve supply to the eye and face. - Guanethidine's mechanism of action would exacerbate, rather than treat, the existing sympathetic deficit in Horner's syndrome.

Q: What is the mechanism of action of quinolones?

Inhibit DNA gyrase. ***Inhibit DNA gyrase*** - Quinolones, particularly **fluoroquinolones**, exert their bactericidal effect by targeting **bacterial DNA gyrase (topoisomerase II)** and **topoisomerase IV**. - This inhibition prevents the uncoiling and replication of bacterial DNA, leading to cell death. *Bind to 30S ribosomal subunit* - This mechanism is characteristic of **aminoglycosides** and **tetracyclines**, which disrupt bacterial protein synthesis. - Quinolones do not interfere with ribosomal function but rather with **DNA replication**. *Bind to bacterial cell membrane* - This is the mechanism of action for **polymyxins** and **daptomycin**, which disrupt the integrity of the bacterial cell membrane. - Quinolones specifically target **intracellular enzymes** involved in DNA handling. *Inhibit tetrahydrofolate reductase* - This enzyme name in the option is technically imprecise; **trimethoprim** actually inhibits **dihydrofolate reductase**, which is part of the **sulfonamide-trimethoprim (Bactrim)** combination. - This pathway is involved in **folic acid synthesis**, crucial for bacterial DNA and RNA production, a mechanism distinct from quinolones.

Question 1

Which oil has the highest concentration of linolenic acid?

Accepted Answer

Soyabean oil

Answer

Safflower oil

Answer

Coconut oil

Answer

Groundnut oil

Question 2

Effect of environment on genes is called?

Accepted Answer

Epigenetics

Answer

Euthenics

Answer

Positive Eugenics

Answer

Negative Eugenics

Question 3

In winter, water vapours and pollutants come to lie in the lowermost layer of atmosphere by -?

Accepted Answer

Temperature inversion

Answer

Acid rain

Answer

Greenhouse effect

Answer

None of the options

Question 4

The odour of cyanide is similar to?

Accepted Answer

Bitter almond

Answer

Rotten egg

Answer

Fish

Answer

Fruity

Question 5

Who discovered the malarial parasite?

Accepted Answer

Charles Louis Alphonse Laveran

Answer

Ronald Ross

Answer

Paul Muller

Answer

Pampania

Question 6

Largest intestinal protozoan is?

Accepted Answer

Balantidium coli

Answer

E. coli

Answer

Giardia

Answer

T. gondii

Question 7

Which of the following statements about corneal dystrophy is true?

Accepted Answer

It is typically bilateral.

Answer

It involves neovascularization.

Answer

It is caused by inflammation.

Answer

It is usually unilateral.

Question 8

What is the treatment of choice for amblyopia?

Accepted Answer

Occlusion therapy

Answer

Corrective spectacles

Answer

Surgical intervention

Answer

Convergent exercises for vision therapy

Question 9

Guanethidine is used in the treatment of which of the following conditions?

Accepted Answer

Thyrotoxic ophthalmopathy

Answer

Ptosis

Answer

Bell's palsy

Answer

Horner's syndrome

Question 10

What is the mechanism of action of quinolones?

Accepted Answer

Inhibit DNA gyrase

Answer

Inhibit tetrahydrofolate reductase

Answer

Bind to 30S ribosomal subunit

Answer

Bind to bacterial cell membrane

NEET-PG 2012

Biochemistry

Community Medicine

Forensic Medicine

Microbiology

Ophthalmology

Pharmacology