Which of the following conditions represents a case of co-dominance genes?
(1) A gene expresses itself, suppressing the phenotypic effect of its alleles.
(2) Genes that are similar in phenotypic effect when present separately, but when together interact to produce a different trait.
(3) Alleles, both of which interact to produce a trait, which may or may not resemble either of the parental types.
(4) Alleles, each of which produces an independent effect in a heterozygous condition.
Which of the following disorders are caused due to recessive autosomal mutations?
(1) Turner's syndrome and sickle cell anaemia
(2) Edward's syndrome and Down's syndrome
(3) Cystic fibrosis and phenylketonuria
(4) Alzheimer's disease and Huntington's chorea
Which of the following is correct ?
(1) Henking discovered the small Y-chromosome.
(2) Drosophila also shows XX-XY sex determination like human.
(3) Birds have ZZ-ZW sex determination, where females are ZZ and males are ZW.
(4) Grasshoppers show XX-XY sex determination.
Which of the following is true for a recessive disease in family A and B?
(1) In family A, both the parents are homozygous recessive.
(2) In family B, both the parents are homozygous dominant.
(3) In family B, both the parents are heterozygous recessive.
(4) In family A, both the parents are heterozygous recessive.
Which of the following occurs due to monosomy of sex chromosome?
(1) Down's syndrome
(2) Turner's syndrome
(4) Sickle cell anaemia
In rabbits, the gene for grey fur (G) is dominant over that for black fur (g). In a litter, if 50% rabbits are grey, then the possible parental cross combination is
(1) GG X Gg
(2) GG X GG
(3) gg X gg
(4) Gg X gg.
Barr body is missing in the female suffering from
(1) Huntington's disease
(2) Tay-sach's disease
(3) Klinefelter's syndrome
(4) Turner's syndrome
Which is genetically not possible?
(1) Hemophilic father transfers the hemophilic gene to his son
(2) Hemophiic father transfers the hemophilic gene to his daughter
(3) Carrier mother transfers the hemophilic gene to her son
(4) Carrier mother trannsfers the hemophilic gene to her daughter
Barr Body is found in the cytoplasm during
(1) interphase in cell of female mammal
(2) interphase in cell of male mammal
(3) prophase in cell of female mammal
(4) prophase in cell of male mammal.
If both parents are carriers for thalassaemia, which is an autosomal recessive disorder, what are the chances of pregnancy resulting in an affected child?
(3) No chance