chApTer-5 : prINcIpLeS OF
INherITANce AND VArIATION
Multiple choice Questions- In a dihybrid test cross when double heterozygote is used
as an individual what ratio will be obtained?
(a) 2:1 (b) 1:2:1
(c) 3:1 (d) 1:1:1:1 - In garden pea, round shape of seeds is dominant over
wrinkled shape. A pea plant heterozygous for round shape
of seed is selfed and 1600 seeds produced during the cross
are subsequently germinated. How many seedlings will have
the parental phenotype?
(a) 400 (b) 1600
(c) 1200 (d) 800 - Two plants one with black flower and other with white
coloured flower were crossed in an experiment. In the next
generation grey coloured flowers were obtained. The reason
for the result is
(a) incomplete dominance (b) pseudodominance
(c) codominance (d) none of the above. - In sickle cell anaemia, the sequence of amino acids from the
first to the seventh position of the b-chain of haemoglobin
S(HbS) is
(a) His, Leu, Thr, Pro, Glu, Val, Val
(b) Val, His, Leu, Thr, Pro, Glu, Glu
(c) Thr, His, Pro, Val, Pro, Val, Glu
(d) Val, His, Leu, Thr, Pro, Val, Glu.
5. Variation of skin colour in human beings is an example
of
(a) epistasis
(b) co-dominance
(c) criss-cross inheritance
(d) polygenic inheritance.
6. Down’s syndrome is
(a) caused due to gene mutation
(b) caused due to aneuploidy of sex chromosome
(c) caused due to loss of one sex chromosome from the
diploid set
(d) an autosomal aneuploidy.
7. Chromosomal mechanism of sex determination in man and
Drosophila is of
(a) XX–XY type (b) XX–XO type
(c) ZW–ZZ type (d) (a) and (b).
8. Linkage was discovered by
(a) Miller (b) Morgan
(c) De Vries (d) Mendel.
9. A child has blood group ‘O’. If father has blood group ‘A’
and mother has blood group ‘B’, work out the genotypes
of the parents.
(a) IAIA and IBi (b) IAi and IBi
(c) IAi and ii (d) ii and IBIB
10. Rate of mutation is affected by
(a) temperature (b) X-rays
(c) gamma rays (d) all of these.
UNIT-VII : GeNeTIcS AND eVOLUTION
Maximise your chance of success and your seat in AIPMT and other PMTs by reading this column. This section is specially designed
to optimise your preparation by practising more and more. It is a unitwise series having chapterwise question bank, allowing you
to prepare systematically and become more competent.
Recall question or single concept question – indicated by a single finger.
Application question or question which requires 2 or 3 concepts to solve - indicated by 2 fingers.
Application question or question which requires 3 or more concepts - indicated by 3 fingers.12