Marriages between close relatives and cousins is not advisable because
More mutations can occur
More recessive defects are likely to appear
More chances are there for $Rh$ blood group anomalies
More chances are there for multiple births
Select incorrect statement
$(A)$ Linked genes cause absolute lethality
$(B)$ Persons affected by $PKU$ do not show mental disorder
$(C)$ $F_{2}$ ratio in codominance and incomplete dominance are same
$(D)$ Sex of male Drosophila is dependent on $Y-$chromosome
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.
What is the correct sequence of the following events
$1.$Formation of the chromosome theory of heredity
$2.$Experiments which proved that $DNA$ is the hereditary material
$3.$Mendel's laws of inheritance-discovery
Code :
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
Select the correct statement: