(a)(i) Turner's syndrome.
(ii) 44 with XO chromosomes - such females are sterile as ovaries are rudimentary. Other features include lack of other secondary sexual characters, short stature and under developed feminine characters.
(b) Such a disorder is caused due to the absence of one of X chromosomes

(a) Genotype of
(i) Homozygous dominant parent- YYRR
(ii) Homozygous recessive parent-yyrr
(b) Gametes produced by both the parents 
(i) YR and (ii) yr
(c) F₁ offsprings
Phenotype - all seeds yellow round and Heterozygous
Genotype - YyRr
(d) Gametes produced by F₁ offsprings
4 types - 

Dominance : One allele expresses itself in the hybrid heterozygous condition, other is suppressed.
Codominance : Both the alleles of a gene express in a heterozygous hybrid containing two dominant alleles
Incomplete dominance: Neither of the two alleles of a gene is completely dominant over the other in heterozygous the hybrid is Intermediate

Phenylketonuria:
It is caused by a recessive mutant allele on chromosome 12.
The affected individuals lack an enzyme that catalyses the conversion of the amino acid phenylalanine into tyrosine.
As a result, phenylalanine is metabolised into phenyl pyruvate, phenyl acetate, etc.
Accumulation of these chemicals in the brain results in mental retardation.
These are also excreted in the urine, as they are not absorbed by the kidney tubules.

Sex-determination in honeybees:
Haplodiploid sex-determination is seen in honeybees; it is based on the number of sets of chromosomes, an individual receives.
When the ovum is fertilised by a male gamete, the zygote (2n = 32) develops into a female, i.e. a queen or worker.
When the ovum develops by parthenogenesis, i.e. without fertilisation, a male individual, called drone is formed.
The male honeybee (drone) is haploid (with n = 16) and forms sperms by mitosis.

(i) The rest of the progeny will be aaBb and Aabb.
(ii) Yes, the genes are linked.
(iii) Yes, there is crossing over, as 10% of the progeny are recombinants.

Klinefelter's syndrome
The individual has 22 pairs of autosome and XY sex chromosomes, i,e.  47 chromosomes.
Symtoms:
The individual is a male.
He shows development of feminine characters like development of breasts.
Body hair is sparse.
The individual is sterile.

Non-disjunction is responsible for chromosomal abnormalities.
Non-disjunction is the phenomenon of failure of segregation of the members of homologous pairs of chromosomes.
XO-abnormality results from fertilisation of an ovum with X-chromosome by a sperm carrying no sex-chromosome.
The individual has underdeveloped feminine characters.
Ovaries are rudimentary.
She is sterile.

The gene for haemophilia is present on the X chromosome, i.e. sex-linked.
The disorder is due to a recessive mutant allele; hence a female with XX sex chromosomes, must be homozygous to produce the disease.
She must receive one of the defective alleles from her haemophilic father and the other X-chromosome with the defective allele from her mother; who is also haemophilic or at least a carrier (heterozygous for the trait, XXh).
The cross is as follows.

1.The gene for haemophilia is present on the X chromosome, i.e. sex-linked.
2.The disorder is due to a recessive mutant allele; hence a female with XX sex chromosomes, must be homozygous to produce the disease.
3.She must receive one of the defective alleles from her haemophilic father and the other X-chromosome with the defective allele from her mother; who is also haemophilic or at least a carrier (heterozygous for the trait, XXh).
4.The cross is as follows.