ABO blood grouping is controlled by gene I which has three alleles and show co- dominance. There are six genotypes. How many phenotypes are possible?
Correct answer: B. Four
- A. Six
- B. Four
- C. Three
- D. Five
Explanation
Option B is correct. The correct answer is four. The ABO blood grouping system is controlled by the ABO gene, which has three alleles: A, B, and O. The A and B alleles are codominant, which means that both alleles are expressed in the phenotype. The O allele is recessive, which means that it is only expressed in the phenotype if the individual does not have any A or B alleles. The six possible genotypes for the ABO gene are: 1.AA 2.AO 3.BB 4.BO 5.AB 6.OO. The four possible phenotypes for the ABO blood grouping system are: 1.A 2.B 3.AB 4.O The A and B phenotypes are produced by the presence of either two A alleles or two B alleles. The AB phenotype is produced by the presence of one A allele and one B allele. The O phenotype is produced by the presence of two O alleles. Therefore, there are four possible phenotypes for the ABO blood grouping system, despite the fact that there are six possible genotypes
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
4 Mutations in opsin genes cause_ types of colorblindness.
9 : 3 : 3 : 1 ratio is given by:
A bald man marries to pattern bald woman. The chance of baldness in their daughter is:
A botanist sees that when he breeds a plant with blue flowers and a plant with red flowers, the resulting generation are plants with a 1:1 ratio of blue: red flowers. He knows that the two parents are homozygous for the trait of color. What phenomenon most likely explains the 1:1 ratio in the filial generation?
A carrier female for hemophilia can pass the defective allele to: