Neco Model Questions Vol1 2025 Biology Question 45

Practice objective / multiple choice question 45 from the 2025 Neco Model Questions Vol1 Biology examination.

Neco Model Questions Vol1 2025 Biology Objective / Multiple Choice Medium Difficulty
Question 45 NECO_MODEL_QUESTIONS_VOL1 • 2025 • BIOLOGY • objective

In peas, the genes for plant height (A = tall, a = dwarf) and seed colour (B = yellow, b = green) are linked on the same chromosome with a recombination frequency of 12 %. A plant heterozygous for both traits (genotype AaBb) is test‑crossed with a homozygous recessive plant (aabb). (a) What phenotypic ratio of the offspring is expected? (b) If 200 offspring are obtained, how many are expected to be tall and yellow?

Answer Options

A. (a) Phenotypic ratio 50 % tall‑yellow : 5 % tall‑green : 5 % dwarf‑yellow : 40 % dwarf‑green (12.5:1.25:1.25:10). (b) Expected tall‑yellow offspring = 100
B. (a) Phenotypic ratio 44 % tall‑yellow : 6 % tall‑green : 6 % dwarf‑yellow : 44 % dwarf‑green (11:1.5:1.5:11). (b) Expected tall‑yellow offspring = 90
Correct Answer C. (a) Phenotypic ratio 44 % tall‑yellow : 6 % tall‑green : 6 % dwarf‑yellow : 44 % dwarf‑green (11:1.5:1.5:11). (b) Expected tall‑yellow offspring = 88.
D. (a) Phenotypic ratio 40 % tall‑yellow : 10 % tall‑green : 10 % dwarf‑yellow : 40 % dwarf‑green (10:2.5:2.5:10). (b) Expected tall‑yellow offspring = 80
Correct Answer
C
Correct Option:
(a) Phenotypic ratio 44 % tall‑yellow : 6 % tall‑green : 6 % dwarf‑yellow : 44 % dwarf‑green (11:1.5:1.5:11). (b) Expected tall‑yellow offspring = 88.

About This Question

This is Neco Model Questions Vol1 2025 Biology Question 45. It is one of the objective questions from the 2025 Neco Model Questions Vol1 Biology examination.

Difficulty level: Medium .

View More Neco Model Questions Vol1 2025 Biology Questions More Neco Model Questions Vol1 Practice Questions Back to Questions

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