Which genotype is responsible for the carrier state of sickle-cell anemia?

In the given pedigree,indicate whether the shaded symbols indicate a dominant or recessive allele.

Hemophilia is more common in males because it is a:

Pick out the correct statements.
$(1)$ Haemophilia is a sex-linked recessive disease.
$(2)$ Down's syndrome is due to aneuploidy.
$(3)$ Phenylketonuria is an autosomal recessive gene disorder.
$(4)$ Sickle cell anaemia is an $X$-linked recessive gene disorder.

If both parents are carriers of thalassemia,which is an autosomal recessive disorder,what is the probability of having an affected child?

From the following pedigree chart of a family,one can make an analysis that: