General Biology & Biochemistry

General Biology & Biochemistry

All of the following are RNA viruses, EXCEPT:

Hepatitis B virus contains partially double-stranded DNA genome replicating via reverse transcription within Hepadnaviridae. Hepatitis A, C and E are positive-sense RNA viruses with RNA-dependent RNA polymerase, contrasting HBV's DNA nature.

Ref: Prescott's Microbiology, Jawetz Medical Microbiology, 28th Edition, Chapter on Hepatitis Viruses, and Knipe and Howley, Fields Virology, 6th Edition, classify Hepatitis B as DNA hepadnavirus versus hepatitis A, C, E as RNA viruses, published by McGraw Hill.

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General Biology & Biochemistry

Which of the following is not an acid-fast parasite?

Cyclospora, Isospora now Cystoisospora, and Cryptosporidium oocysts resist acid-fast decolorization due to lipid-rich walls, staining red with modified Ziehl-Neelsen. Entamoeba histolytica cysts lack mycolic acid, non-acid-fast, visualized by trichrome iodine.

Ref: Paniker's Textbook of Medical Parasitology, 8th Edition, Chapter on Intestinal Protozoa, and Garcia, Diagnostic Medical Parasitology, describe acid-fast staining of coccidian parasites Cryptosporidium, Cyclospora, Isospora excluding Entamoeba, published by Jaypee Brothers.

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General Biology & Biochemistry

All of the following are examples of gram-negative bacilli, EXCEPT:

Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis are Gram-negative rods of Enterobacteriaceae family. Enterococcus faecalis is Gram-positive cocci in chains, catalase-negative, causing urinary infections but fundamentally different cell wall structure.

Ref: Prescott's Microbiology, 11th Edition by Willey, Sherwood and Woolverton, Chapter on Gram-Negative and Gram-Positive Bacteria, and Ananthanarayan and Paniker's Textbook of Microbiology, discuss Enterococcus as Gram-positive cocci, published by McGraw Hill.

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General Biology & Biochemistry

The players of a football team (excluding substitutes) were advised to stand as per the ascending order of their height.

Football team has eleven players excluding substitutes. Sorted ascending, median position equals (n+1)/2 equals sixth observation. Eleven odd-numbered dataset median is middle value, not average required of two central values.

Ref: Gupta and Kapoor, Fundamentals of Mathematical Statistics and Daniel, Biostatistics Chapter on Central Tendency defines median position calculation for odd number observations as (n+1)/2th value, published by Sultan Chand.

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General Biology & Biochemistry

Which of the following example represents nominal data in statistics?

Nominal data classify into unordered categories without intrinsic ranking. Rainbow colours represent distinct labels with no quantitative order or magnitude, unlike blood pressure, age continuous, or pain ordinal graded mild to severe.

Ref: Daniel, Biostatistics: A Foundation for Analysis in Health Sciences, 11th Edition, Chapter on Types of Data, defines nominal scales exemplified by colors and categories lacking order, published by Wiley.

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General Biology & Biochemistry

Which of following guidelines should be followed while reporting the results from a randomized clinical trial?

CONSORT checklist provides standardized framework for reporting randomized trials including randomization, blinding and participant flow. Adherence ensures transparency, reduces bias and enables reproducibility, unlike PRISMA for systematic reviews or STROBE for observational studies.

Ref: Schulz, Altman and Moher, CONSORT 2010 Statement published in BMJ, Lancet, PLOS Medicine, guidelines explain Consolidated Standards of Reporting Trials for randomized clinical trial transparency, endorsed by ICMJE, published by British Medical Journal.

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General Biology & Biochemistry

In a study, 5000 patients are randomly divided into two groups, one is administered 100 mg of a drug, the other gets pla

Incidence represents categorical outcome stroke yes/no in two independent groups drug versus placebo. Chi-square test compares proportions of categorical outcomes, assessing independence. Mann-Whitney, t-test and Wilcoxon apply to continuous or ranked data, not binary incidence comparison.

Ref: Rosner, Fundamentals of Biostatistics, 8th Edition, Chapter on Categorical Data Analysis, and Daniel, Biostatistics, discuss chi-square test for comparing incidence proportions between two randomized groups, published by Cengage Learning and Wiley.

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General Biology & Biochemistry

Modification of behaviour by study participants in response to their knowledge that they are being observed is known as:

Hawthorne effect describes participants altering performance because awareness of observation creates attention motivation. Initially observed at Hawthorne Works factory, this reactivity biases observational studies, requiring blinding or unobtrusive measures to mitigate.

Ref: Rothman, Modern Epidemiology and Park's Textbook, Chapter on Bias, and original Mayo et al. Hawthorne studies literature define Hawthorne effect as behaviour change due to observation awareness, published by Lippincott Williams and Wilkins.

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General Biology & Biochemistry

One study intended to compare 12-hour nursing shifts to 8-hour shifts to assess the effects on patient outcomes in the d

Randomizing individual nurses would contaminate within wards. Cluster randomization randomizes whole wards to shift lengths, preserving routine and reducing cross-over bias, then measures patient outcomes hierarchically, suitable for health services intervention evaluation.

Ref: Murray, Cluster Randomised Trials, and Rothman and Greenland, Modern Epidemiology, 4th Edition, Chapter on Experimental Designs, discuss cluster randomized trials for hospital ward-level interventions to avoid contamination, published by Chapman and Hall and Lippincott.

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General Biology & Biochemistry

Which one of the following is unaffected by outliers?

Interquartile range equals Q3 minus Q1, capturing middle 50 percent. Unlike mean, standard deviation and range which use extremes, IQR relies on resistant quartiles, making it robust against outliers and skewed distributions.

Ref: Gupta, Biostatistics and Epidemiology texts like Park's Textbook and Rosner, Fundamentals of Biostatistics, 8th Edition, Chapter on Dispersion, explain interquartile range robustness to outliers versus range and standard deviation, published by Cengage Learning.

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General Biology & Biochemistry

The statistical term to represent the most frequently selling commodity of a shop?

Mode denotes value occurring most frequently in dataset. For shop sales, item with highest purchase frequency reflects consumer preference. Unlike median or percentile, mode directly identifies dominant category, crucial for inventory management decisions.

Ref: Gupta S.C. Fundamentals of Statistics, 7th Edition, Chapter on Central Tendency, and Daniel, Biostatistics, define mode as most frequent observation in sales and biological data analysis, published by Himalaya Publishing House.

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General Biology & Biochemistry

The mean of 20 observations is 6.21. Later on, it was discovered that the two items +5 and +3 were taken as -5 and -3. F

Incorrect total equals 20 multiplied by 6.21 equaling 124.2. Sign error contributed -8 instead of +8, underestimating sum by 16. Adding back 16 gives 140.2, dividing by 20 yields corrected mean 7.01, illustrating mean sensitivity to data entry.

Ref: Gupta S.C. and Kapoor V.K., Fundamentals of Mathematical Statistics, 12th Edition, Chapter on Measures of Central Tendency, explains mean calculation corrections and error rectification methods, published by Sultan Chand and Sons.

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