Question

which of the human genetic disorder of blood is controlled by incomplete alleles what happens in it​

Answer 1

Answer:

There are three types of genetic disorders:

1) Single-gene disorders, where a mutation affects one gene. Sickle cell anemia is an example.

2) Chromosomal disorders, where chromosomes (or parts of chromosomes) are missing or changed.

3) Complex disorders, where there are mutations in two or more genes.

Answer 2

Answer:

Sickle Cell Anaemia is a human blood genetic disorder that is controlled by incomplete alleles. This disorder is characterised by sickling of RBCs.      

Explanation:

• Codominance, as it connects with hereditary traits, alludes to a sort of legacy wherein two allelic forms of similar quality are communicated independently to yield various characteristics in a person.

• That is, rather than one quality being prevailing over the other, the two characteristics express up(incompletely or partially), for example, in a plant or animal that has more than one skin tone.

• Sickle cell anaemia is used to demonstrate the concepts of co-dominance governed by incomplete alleles.

• A person with the sickle cell trait shows incomplete dominance when the shape of the red blood cell is taken into observation.

• This autosome-linked recessive trait can be transmitted from parents to the offspring when both the partners are carriers of the gene (or heterozygous). The disease is controlled by a single pair of alleles $Hb^{A}$ and $Hb^{S}$.

• Out of the three possible genotypes only homozygous individuals for $Hb^{S}$ ($Hb^{S}Hb^{S}$) show the diseased phenotype.

• Heterozygous ($Hb ^{A} Hb^{S}$) individuals remain unaffected but they act as carriers of the disease as there is a 50 per cent probability of transmission of the mutant gene to the progeny, thus exhibiting sickle-cell trait.

• The defect is caused by the substitution of Glutamic acid (Glu) by Valine (Val) at the 6th position of the β-globin chain of the haemoglobin molecule. The substitution of amino acids in the globin protein results due to the single base substitution at the 6th codon of the β globin gene from GAG to GUG.

• The mutant haemoglobin molecule undergoes polymerisation under low oxygen tension causing the change in the shape of the RBC from a biconcave disc to an elongated sickle-like structure.

• Since Phenylketonururia is a brain & nervous tissue-related genetic disorder and colour blindness is a colour vision-related genetic disorder, sickle cell anaemia is the right answer.

#SPJ3

[The above-mentioned question is incomplete, but most likely the full question was-

Which of the human genetic disorder of blood is controlled by incomplete alleles. What happens in it​?

Sickle cell Anaemia

Colour blindness

Phenylketonuria]