Expression of the a and b antigens on red blood cells is influenced by the fut1 gene. this gene encodes fucosyl transferase, an enzyme that produce the h substance. which of the following statements about the h substance is incorrect?
(a) individuals that cannot produce the h substance appear to be type o even if they have functional a and/or ib alleles.
(b) individuals that fail to produce the h substance are said to have the bombay phenotype.
(c) individuals that are heterozygous for the fut1 gene cannot produce the h substance
(d) the h substance is a substrate for the enzymes produced by the n and β genes. these enzymes add the appropriate terminal sugar to the h substance producing the a and b antigens, respectively.

The correct answer is option C

Explanation:

Bombay phenotype refers to a rare genetic trait in which a person appears as blood group O even in presence of functional A, B, or AB alleles.

It is because of recessive mutation that occurs in other locus, that is, FUT1 gene. Normal gene produces H antigen or protein in the cell. This antigen is essential for the final expression of the ABO alleles.

If a person is homozygous recessive then he or she is not able to produce H antigen due to which the blood group appears as O.

However, if a person carries even a single functional copy of FUT1 gene, that is, heterozygous or homozygous then he or she can efficiently produce H antigen and then ABO alleles are expressed accordingly.

Thus, option C contains incorrect statement.

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.