Moderate

Genes P, Q, R, and S occur on the same chromosome.Investigation of a large population produced the following cross-over values between pairs of genes.P and R 34% P and Q 59% R and S 12% S and Q 37% Which of the following sequences represents the sequence of genes on the chromosome?

Correct answer: B. PSRQ

  • A. PRSQ
  • B. PSRQ
  • C. QSPR
  • D. RQSP
  • E. SPRQ

Explanation

This is a tricky question. A question like this also appeared in the AKU 2022 test. Basically, the greater the crossing over percentages, the more the distance between them. P and Q will be farthest from each other. So, we have P in the start and Q at the end. Now we have to find whether S comes first or R. PR frequency is more than PS so S will closer to P. Combining all this data, we get the sequence of PSRQ.

Last updated

About Inheritance

Mendel's laws explain segregation, independent assortment and the prediction of genetic ratios using alleles, genotypes and phenotypes. The chapter also covers linked genes, recombination and crossing over during meiosis, then applies pedigree reasoning to X-linked recessive traits, which show different inheritance patterns in males and females.

Practise Inheritance

1,238 free Inheritance MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Exams that ask Biology questions like this

Biology is on 6 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

Related questions