An abnormal human baby with 'XXX' sex chromosomes was born due to
formation of abnormal sperms in the father
formation of abnormal ova in the mother
fusion of two ova and one sperm
fusion of two ova and one sperm
B.
formation of abnormal ova in the mother
Formation of an abnormal ova usually occurs as an event during the formation of reproductive cells.
An error in cell division called non-disjunction can result in reproductive cells with additional chromosomes. Any of these cells if contributes in the genetic make up of child leads to trisomy of X-chromosome i.e. the child will have an extra X-chromosome. ZZ+ XX in mother will lead to birth of XXX genotype baby.
Represented below is the inheritance pattern of a certain type of traits in humans. Which one of the following conditions could be an example of this pattern?
Phenylketonuria
Sickle cell anaemia
Haemophilia
Haemophilia
A man whose father was colour blind marries a woman, who had a colourblind mother and normal father. What percentage of male children of this couple will be colourblind.
25%
0%
50%
50%
Alleles are
different phenotype
true breeding homozygotes
different molecular forms of a gene
different molecular forms of a gene
The idea of mutations was brought forth by
Hugo de Vries, who worked on evening primrose
Gregor Mendel, who worked on Pisum sativum
Hardy Weinberg, who worked on allele frequencies in a population
Hardy Weinberg, who worked on allele frequencies in a population
A human female with Turner's syndrome
has 45 chromosomes with XO
has one additional X - chromosome
exhibits male characters
exhibits male characters
Multiple alleles are present
On different chromosomes
At different loci on the same chromosome
at the same locus of the chromosome
at the same locus of the chromosome
A test cross is carried out to
determine the genotype of a plant at F2
predict whether two traits are linked
assess the number of alleles of a gene
assess the number of alleles of a gene
F2 generation in a Mendelian cross showed that both genotypic and phenotypic ratios are same as 1:2:1. It represents a case of
codominance
dihybrid cross
monohybrid cross with complete dominance
monohybrid cross with complete dominance
Which one of the following is a wrong statement regarding mutations?
Deletion and insertion of base pairs cause frame-sheft mutations
Cancer cells commonly show chromosomal aberrations
UV and Gamma rays are mutagens
UV and Gamma rays are mutagens
