Methods in Biostatistics — DU B.Sc. (Hons.) Zoology Previous Year Question Papers

(b) A microbiologist observes that a specific rare bacteria appears at an average rate of 2 = 3 cells per microscope field. Calculate the probability of finding exactly 5 bacterial cells in a randomly selected microscope field. (Given e=3~0.0498). (c) Discuss Skewness and Kurtosis with diagrams, wherever required. 5. (a) Explain Null and Alternative hypotheses. Discuss 1 ee 1 and Type IT errors with suitable biological examples. (b) The mean height of 50 plants is claimed to be 120 cm with a standard deviation of 10 cm. A random sample of 25 plants shows a mean height the him at s% leve of sit, tea ta validity of 6. (a) The weights (in grams) of an organism under The wiferent diets are give below: Diet A: 18, 20, 19 i Using one-way ANOVA, test whether there is a significant difference between the mean Weights of organisms (Take a = 0.05) (b) Write a short note on Correlation coefficient. NEP - UGCF (c) Statistical tables and graph paper should be provided. (d) Attempt four questions in all, including 1. (a) Define the following (Any FIVE) 1x5=5 (iii) Sampling • (V) Standard Déviation to) Differentiate between the following (Any THREE) 3x2=6 (iii) Compute the total Chi-Square (%2) value for the dataset. (i) Primary and secondary data (iv) Determine the degrees of freedom for this (ii) Discrete and Continuous dat.a. (iii) Mean and Median ro) Describe various sampling methods used in biological research. 7 (iv)' Parameter and Statistic 8. (a) Describe measures of central tendeney. (c) Fill in the blanks Explain mean, median and mode with The study of chance is knctwn as suitable examples. 7 The graphical representation of frequency distribution is called (b) A pharmacologist is studying the relationship between the dosage of a new drug (in mg) and (±ii) The measure of relative dispersion is known as the reduction in blood pressure (in mmHg) in 5 test subjects. The data is as follows: (iv) The probability Lion applicable to rare events is istribution. BP Red ction in: 5, 9, 14, 2o, 24 2. (a) Abotanistperformsadihyb cross of pea plants ulate the Pearson Correlatioh and expects a standard M fficient (Srs) to determine the phenotypicratioof9:3:3:1 Or four different traits gth and direction of the relationship gen drug dosage and BP reduction. (Round-Yelldr, rRound-Gr6en, Wrinkled-Yellow, Wrinkled-Green). Out of a total of 320 offspring (ii) Perform a linear regression analysis to find the equatictn of the regression line evaluated, the observed counts are: Round- Yellowl90; Round-Green 55; Wrinkled-Yellow •65; Wrinkled-Green 10 Use the .Chi-Square test (y=mx + c) to .predict the BP reduction for a given dosage. 4 for Goodness of Fit to evaluate this data. (i) (ii) 4. (a) In a specific genetic cross of fruit flies, the State the Null and Altemative hypotheses for this experiment. probabilrty of an offspring inheriting a recessive mutation i§ 0.25. If a geneticist isolates 6 offspring, what is the exact probability that