Mention any two autosomal genetic disorders with their symptoms.
Two autosomal genetic disorders are as follows. sickle cell anaemia It is an autosomal linked recessive disorder, which is caused by point mutation in the beta-globin chain of haemoglobin pigment of the blood. The disease is characterized by sickle shaped red blood cells, which are formed due to the mutant haemoglobin molecule. The disease is controlled by $\mathrm{Hb}^{\mathrm{A}}$ and $\mathrm{Hb}^{\mathrm{S}}$ allele. The homozygous individuals with genotype, $\mathrm{Hb}^{\mathrm{S}} \mathrm{Hb}^{\mathrm{S}},$ show the symptoms of this disease while the heterozygous individuals with genotype, $\mathrm{Hb}^{\mathrm{A}} \mathrm{Hb}^{\mathrm{S}},$ are not affected. However, they act as carriers of the disease.
Symptoms
Rapid heart rate, breathlessness, delayed growth and puberty, jaundice, weakness, fever, excessive thirst, chest pain, and decreased fertility are the major symptoms of sickle cell anaemia disease.
Down's syndrome
It is an autosomal disorder that is caused by the trisomy of chromosome $21$.
Symptoms
The individual is short statured with round head, open mouth, protruding tongue, short neck, slanting eyes, and broad short hands. The individual also shows retarded mental and physical growth.
Choose correct option.
$(i)$ The heterozygous female transmit the disease to son.
$(ii)$ Change in the shape of the $RBC$ from biconcave disc to elongated sickle like structure.
$(iii)$ Mentally retarded.
$(iv)$ Heamoglobin not formed proper amount in blood.
Describe Mendelian Disorder.
In pedigree analysis, symbol given for sex unspecified is
Sickle cell anaemia is due to
It is said, that the harmful alleles get eliminated from population over a period of time, yet sickle cell anaemia is persisting in human population. Why ?