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

  • A

    $(A) \;\& \;(B)$

  • B

    $(B) \;\&\; (C)$

  • C

    $(A), (B) \;\&\; (D)$

  • D

    All of these

Similar Questions

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.

  • [NEET 2016]

Match the terms in column $I$ with their description in column $II$ and choose the correct option.

Column $-I$ Column $-II$
$(A)$ Dominance $(i)$ Many genesgovern a single character
$(B)$ Codominance $(ii)$ In a heterozygousorganism only one allele expresses itself
$(C)$ Pleiotropy $(iii)$ In a heterozygousorganism both alleles express themselves fully
$(D)$ Polygenic $(iv)$ A single gene inheritanceinfluences many characters

  • [NEET 2016]

Choose correct answer :

$(i)$ Queen Elizabeth shows a number of haemophilic descendents.

$(ii)$ Variation in blood group prevalences due to incomplete dominance.

$(iii)$ Drosophila has three pairs of autosomal chromosomes.

$(iv)$ In birds, female is heterozygous.

Marriages between close relatives and cousins is not advisable because