CBSE
Multiple Choice QuestionsIf 'A' represents the dominant gene and 'a' represents its recessive allele, which of the following would be the most likely result in the first generation offspring when Aa is crossed with aa ?
All will exhibit dominant phenotype
All will exhibit recessive phenotype
Dominant and recessive phenotypes will be 50% each
Dominant phenotype will be 75%
Assertion : Number of chromosomes in one genome is equal to number of linkage groups.
Reason : Linkage groups give important information about the location of genes in the chromosomes.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false
If both assertion and reason are false
Assertion : Curdling is required in the manufacture of cheese.
Reason : Lactic acid bacteria are used for the purpose.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Assertion: XX-XY type of sex determination mechanism is an example of female heterogamety and is found in Drosophila.
Reason: Male heterogamety is seen in moths where males produce two different types of gamete.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion : Foetal disorders can be diagnosed by chorionic villi sampling.
Reason : Karyotyping can be done for mitotically dividing cells of chorionic villi.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
If both parents are carriers for thalassaemia, which is an autosomal recessive disorder, what are the chances of pregnancy resulting in an affected child?
25%
100%
No chance
50%
Barr body is missing in the female suffering from
Huntington's disease
Tay-sach's disease
Klinefelter's syndrome
Turner's syndrome.
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
GG x Gg
gg X gg
GG x GG
Gg x gg
Which of the following occurs due to monosomy of sex chromosome
Down's syndrome
Turner's syndrome
Haemophilia
Sickle cell anaemia
Which is genetically not possible
Haemophilic father transfers the haemophilic gene to his son.
Haemophilic father transfers the haemophilic gene to his daughter.
Carrier mother transfers the haemophilic gene to her son.
Carrier mother transfers the haemophilic gene to her daughter
