Multiple Choice QuestionsAssertion : A gamete may carry either of the traits but not both.
Reason : This is Mendel's second law or law of independent assortment.
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
C.
If assertion is true but reason is false
The law of segregation states that the two alleles controlling each character maintain identity in the organism but during the formation of gametes or spores by meiosis move apart due to separation of the homologous chromosomes which bear them, so that each gamete or spore receives only one allele of each character on random basis.
Since the gametes or spores possess one allele of each character, they are always pure. The law of segregation is, therefore, also called the law of purity of gametes/spores.
Mendel's second law or the law of independent assortment states that the alleles of different characters located in different pairs of homologous chromosomes are independent of one another in their segregation during gamete formation and in coming together into the offspring by fertilization, both processes occurring randomly.
The distance between two genes in a chromosome is measured in cross-over units which represent
ratio of crossing over between them
percentage of crossing over between them
number of crossing over between them
none of these.
Assertion: Persons suffering from haemophilia fail to produce blood clotting factor VIII.
Reason: Prothrombin producing platelets in such persons are found in very low concentration.
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.
XO-chromosomal abnormality in human beings causes
Turner's syndrome
Down's syndrome
Klinefelter's syndrome
None of these
If a homozygous red-flowered plant is crossed with a homozygous white-flowered plant, the offsprings will be
half- white flowered
half- red flowered
all white flowered
all red flowered
Gene which suppresses other gene's activity but does not lie on the same locus is called as
epistatic
supplementary
hypostatic
codominant
Pure line breed refers to
heterozygosity only
heterozygosity and linkage
homozygosity only
homozygosity and self assortment
Assertion : Haemophilia is a recessive sex linked disease.
Reason : Haemophilia occurs due to mutation of a structural gene on chromosome 15.
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
Which one of the following pairs of features is a good example of polygenic inheritance
Human height and skin colour
ABO blood group in humans and flower colour of Mirabilis jalapa
Hair pigment of mouse and tongue rolling in humans
Human eye colour and sickle cell anaemia
Mating of an organism to a double recessive in order to determine whether it is homozygous or heterozygous for a character under consideration is called
reciprocal cross
dihybrid crossn
test cross
back cross
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