Which of the following is true about linkage
$I.$ It is phenomenon in which more recombinants are produced in $F_{2}$-generation
$II.$ More parental combination are produced in $F_{2}$-generation
$III.$ Genotype which are present in $F_{1}$ hybrid. Reappear in high frequency in $F_{2}$-generation
$IV.$ It is a phenomenon in which two chromosome are linked
Only $I$
Only $II$
$I$ and $III$
$III$ and $IV$
Which of the following pairs is $wrongly$ matched?
Match the following:
Column $- I$ | Column $- II$ |
$(1)$ Inheritance of two genes | $(a)\; ABO$ blood group |
$(2)$ Incomplete dominance | $(b)\; 1:2:1$ |
$(3)$ Codominance | $(c)\;9:3:3:1$ |
$(4)$ Inheritance of one gene | $(d)\; 3:1$ |
Marriages between close relatives and cousins is not advisable because
How many sentence are correct ?
$(i)$ Every gene contains the information to express a particular trait.
$(ii)$ Gene responsible for $\beta$ - thalassemia is present on $21^{st}$ pair of autosomal chromosome.
$(iii)$ Mendel's approach of using mathematics to explain biological phenomena was totally new and unacceptable to many of the biologists of his time.
Pick out the correct statements.
$(1)$ Haemophilia is a sexlinked recessive disease.
$(2)$ Down’s syndrome is due to aneuploidy.
$(3)$ Phenylketonuria is an autosomal recessive gene disorder.
$(4)$ Sickle cell anaemia is an $X$-linked recessive gene disorder.