Waec Model Questions Vol1 2025 Biology Question 15

Practice objective / multiple choice question 15 from the 2025 Waec Model Questions Vol1 Biology examination.

Waec Model Questions Vol1 2025 Biology Objective / Multiple Choice Medium Difficulty
Question 15 WAEC_MODEL_QUESTIONS_VOL1 • 2025 • BIOLOGY • objective

In a plant species two traits are studied: flower colour (R = red dominant, r = white recessive) and plant height (T = tall dominant, t = dwarf recessive). A true‑breeding red‑tall plant (RR TT) is crossed with a white‑dwarf plant (rr tt) to produce F₁. Two F₁ individuals are then crossed to obtain F₂. Among 200 F₂ offspring the observed numbers are: 48 white‑dwarf, 52 white‑tall, 68 red‑dwarf and the remainder red‑tall. Using a chi‑square test at the 5 % significance level, determine whether the observed phenotypic distribution fits the expected 9:3:3:1 ratio.

Answer Options

A. χ² ≈ 0.5; deviation is not significant - the observed ratio fits 9:3:3:1
Correct Answer B. χ² ≈ 189; deviation is significant - the observed ratio does not fit 9:3:3:1
C. χ² ≈ 3.84; deviation is not significant - the observed ratio fits 9:3:3:1
D. χ² ≈ 12.5; deviation is significant - the observed ratio does not fit 9:3:3:1
Correct Answer
B
Correct Option:
χ² ≈ 189; deviation is significant - the observed ratio does not fit 9:3:3:1

About This Question

This is Waec Model Questions Vol1 2025 Biology Question 15. It is one of the objective questions from the 2025 Waec Model Questions Vol1 Biology examination.

Difficulty level: Medium .

Master the Exam!

You've seen a preview, but there are thousands more questions plus AI tutor to break down complex solutions.

Unlock Full Access Available for Android & Windows
Chat with Support