FOUR-YEAR UNDERGRADUATE PROGRAMME (FYUGP)
B.Sc. 4th Semester (Major) Examination
Subject: Zoology
Paper: ZOO-MAJ-4.1 (Animal Taxonomy, Systematics, and Biostatistics)
Time Allowable: 2 Hours
Full Marks: 45
The figures in the margin indicate full marks for the questions. Answer Part-A (Taxonomy & Systematics) and Part-B (Biostatistics) as instructed.
SECTION — A (1x5 = 5 Marks)
1. Answer the following questions as directed: (Any five)
a) Who proposed the "Biological Species Concept"? (Fill in the blank)
b) Define Holotype. (Answer in one sentence)
c) Name a modern taxonomic key that provides two contrasting choices at each step. (Answer in one word)
d) State the algebraic relationship between Mean, Median, and Mode in a moderately asymmetrical distribution. (Write the formula)
e) If the Variance of a biological data set is 16, what is its Standard Deviation? (Calculate)
f) What is the value of total probability of a certain event and an impossible event combined? (Answer in one word) ---
SECTION — B (2x5 = 10 Marks)
2. Answer any five of the following questions within 30–50 words each:
a) Differentiate between Alpha ($\alpha$) and Beta ($\beta$) taxonomy.
b) Explain the Law of Priority as per ICZN guidelines.
c) What do you mean by a Cladogram? How does it differ from a Phenogram?
d) Distinguish between Primary data and Secondary data with examples relevant to field zoology.
e) Define Type-I ($\alpha$) and Type-II ($\beta$) errors in hypothesis testing.
f) State two differences between Standard Deviation and Standard Error of Mean (SEM).
SECTION — C (5x2 = 10 Marks)
3. Answer any two of the following questions within 150 words each:
a) Write a comprehensive note on the Principle of Typification in zoological nomenclature, detailing at least four types of type-specimens.
b) What are Infraspecific categories? Explain the concept of Subspecies, Clines, and Demes with suitable examples.
c) Explain the step-by-step procedure of executing a Student's t-test for a paired biological sample. State its applications in biological research.
d) What is a Phylogenetic tree? Differentiate clearly between Homology and Analogy with suitable zoological examples, explaining their significance in constructing evolutionary relationships.
e) Write a explanatory note on Probability Distributions. Briefly distinguish between Binomial Distribution and Normal Distribution, highlighting their primary characteristics in biological data analysis.
SECTION — D (10x2 = 20 Marks)
4. Answer any two of the following long-answer questions:
a) Systematics Unit: What is biological classification? Critically analyze the Biological Species Concept. Discuss its relative merits and limitations when applied to asexual organisms and fossil records. (2 + 4 + 4 = 10 Marks)
b) Biostatistics Numerical Unit: The table below shows the number of segmentations observed in an earthworm population collected near the Kopili River basin, Hojai. Calculate the Mean and Standard Deviation for the given grouped data: (5 + 5 = 10 Marks)
| Number of Segments (Class Interval) | Number of Earthworms (Frequency) |
| 80 – 90 | 4 |
| 90 – 100 | 6 |
| 100 – 110 | 10 |
| 110 – 120 | 7 |
| 120 – 130 | 3 |
c) Statistical Inference Unit:
(i) State the mathematical formula for the Chi-Square ($\chi^2$) test. Explain what "Goodness of Fit" means. (2 + 3 = 5 Marks)
(ii) In a Mendelian cross of fruit flies (Drosophila), the expected phenotypic ratio of wild-type to mutant features is 3:1. However, an entomologist observes 70 wild-type flies and 30 mutant flies. Frame the Null Hypothesis ($H_0$) and test if the observed data fits the expected Mendelian distribution. (Given: Critical $\chi^2$ value at 1 degree of freedom at 5% significance level is 3.84) (5 Marks)
d) (i) What is the International Code of Zoological Nomenclature (ICZN)? Discuss its fundamental objectives. (3 Marks)
(ii) Explain the following terms with reference to zoological nomenclature guidelines: Homonyms, Synonyms, Tautonyms, and the Principle of Coordination. (7 Marks)
e) (i) What is ANOVA (Analysis of Variance)? State the basic assumptions required to perform a One-way ANOVA on biological data. (4 Marks)
(ii) An aquarium experiment was conducted to test the effect of three different fish feeds (Feed A, Feed B, and Feed C) on the weight gain (in grams) of Tilapia fish over a month. Outline the step-by-step structural procedure to set up an ANOVA Table (including Sum of Squares, Degrees of Freedom, Mean Squares, and the F-ratio) to test if the variances between the feed types are significantly different. (6 Marks)