In: Biology
i. is dominant over the allele that produces B carbohydrates.
ii. is recessive to the allele that produces B carbohydrates.
iii. is incompletelydominant over the allele that produces B carbohydrates.
iv. is co-dominant with the allele that produces B carbohydrates.
i. is dominant over the allele that produces nocarbohydrates.
ii. is recessive to the allele that produces nocarbohydrates.
iii. is incompletelydominant over the allele that produces nocarbohydrates.
iv. is co-dominant with the allele that produces nocarbohydrates.
i. The allele that produces A carbohydrates.
ii. The allele that produces B carbohydrates.
iii. The allele that produces no (O) carbohydrates.
1) The correct option is (iv) - the allele that produces A carbohydrate is co-dominant with the allele that produces B carbohydrate.
This is an example of Co-dominance. Co-dominance is a form of inheritance wherein the alleles of a gene pair in a heterozygote are fully expressed. In the given condition, both the genes produce a functional protein and hence they both show dominance. This means if these genes are present in heterozygote condition, then they both will be expressed in the phenotype.
Option (i) is incorrect because allele that produces B carbohydrate also shows dominance and hence allele that produces A carbohydrate cannot dominate the other allele.
Option (ii) is incorrect because allele that produces A carbohydrate also shows dominance and hence allele that produces B carbohydrate cannot dominate the other allele.
Option-(iii) is incorrect because allele that produces A carbohydrate generates a functional protein individually and so does the other allele. Hence, it can not be incompletely dominant over the allele that produces B carbohydrates.
2) The correct option is (i) the allele that produces B carbohydrates is dominant over the allele that produces no carbohydrates.
As the allele that cannot mark RBCs with any carbohydrates is recessive as it is unable to produce a functional protein. Therefore, the B allele that produces a functioning protein is dominant over the allele with no functional protein.
Option (ii) is incorrect because the B allele produces a functional protein and hence dominant. Thus it cannot be recessive to allele with no functional protein.
Option(iii) is incorrect because the B allele produces a functional protein individually and expresses completely when it is present with an allele that produces a non-functional protein.
Option(iv) is incorrect because allele B expresses itself completely when it is present with an allele that produces a non-functional protein.
3) The correct options are (i) and (ii) because they are dominant as they produce a functional protein individually and thus should be represented by a capital letter.
Option (iii) is incorrect because allele that produces no carbohydrates is recessive and hence should be represented by a small letter.