CHAPTER Principles of
4 Inheritance and
Variation
RA ndel's Laws of Inheritance ~rec n pod colour
1.1,,, ,v,e
~
(cl) Round seed shape (2003)
b low are two statements :
8. 1hr genes controlJing the seven pea characters
Gh'e~e:t I . Mendel studied seven pairs of
studied by Mendel are now knowri o be located on
State ting traits m pea plants and proposed the how many different chromoson ,ec 1
·ontras .
l
0
f inhentance. (a) Seven (b) jw
15
;a,itateltle nt II . Seven characters examined by Mendel
· (c) Five .._jaffour (2003)
S . xmeriment on pea plants were seed shape and
1n~e~ d h 9. According to Mendelism, which character shows
flower colour, po s ape and colour, flower dominance?
1
coour, h.h
position and stem e1gb t. (a) Terminal position of flower
the light of the a ove statements, choose the (b) Green colour in seed coat
In ct answer from the options given below : (c) }¼ink.led seeds
$Both Statement I and Statement II are correct ~ Green pod colour (2000)
1,) Both Statement I and Statement II are incorrect 10. First geneticist/father of genetics was
(c) Statement I is correct but Statement II is (a) De Vries (b) Mendel
mcorrect {ii) (c) Darwin (d) Morgan. (1991,
[d) Statement I is incorrect but Statement II - 11 . Which contribute to the success of Mendel?
is correct (2022) (a) Qualitative analysis of data
, How many true breeding pea plant varieties 'did (b) Observation of distinct inherited traits
Mendel select as pairs, which were similar except in (c) His knowledge of biology
one character with contrast~ traits? (d) Consideration ofone character at one time (1988)
(a) 4 (b) 2 u,e1"14 (d) 8 (2020)
3. Among the following characters, which on_ e was not 4.2 Inheritance of One Gene
considered by Mendel in his experiments on pea?
12. The production of gametes by the parents, formation
~richomes-Glandular or non-glandular ~ of zygotes, the F1 and F2 plants, can be understood
(b} Seed-Green or yellow (iJJ from a diagram called
(c} Pod-Inflated or constricted - (a) net square (b) bullet square
(d) Stem-Tall or dwarf (2017) (c) punch square ,J4' Punnett square (2021
4. Which one from those given below is the period for 13. In a cross between a male and female, both
Mendel's hybridisation experiments? heterozygous for sickle cell anaemia gene, what
(a) 1840-1850 (~)~ 857- 1869 percentage of the progeny will be diseased?
. (c) 1870-1877 \jJkJ 1856- 1863 (2017) (a) 100% 1
(b) _)0%
l. In his classic experiments on pea plants, Mendel did (c) 75% uaf 25% (2021)
not use
I 4. Identify the wrong statement with reference to the
;a) seed shape (b) flower position gene T that controls ABO blood groups.
c) seed colour ~ o d length. (201 5) (a) The gene (J) has three alleles. _
6, ij
t
many pairs of contrasting characters in pea
lain~ Were studied by Meng.pl in his experiments?
(b)_faPerson will have only two ot the three alleles.
# When JA and JB are present together,
( Eight \W) Seven they express same type of sugar. (
i, c) _Five (d) Six (2015 Cancelled) (d) Allele i does not produce any sugar.
~~h 0
ne of the following traits of garden pea
15. In Antirrhinum (Snapdragon), a red flower was
(2020)
9ie~ by Mendel was a recessive feature?
1 (b) ~al flower position
crossed with a white flower and in FI generation
reen seed colour all pink flowers were obtained. When pink flowers
,38 ~-tG- NEET-AIPMT Chapterwise Topicwise
So1ur
'A If blood group : 'B' 11 ) ood grou . ions ~: ,
"".ere selfed, the F) gene, at ion showed white, red ,,nd I . f . Pin
Modern teeI1mguc o protein elect I : 2.
'
prnk f1owcrs. l hoosc the incorrect s1,,1cmcnls from Jrcsencc of both 'A' and 'B' typ rophore,r· I t~
~h_c f<2!Jowing. I . cl . .d l . e Prot . ,~t 11,
blood group rn .1v1 ua s.1h1s in an CJc e1 0,, tn_ev11i
~aw ~)! segregation docs 1101 apply in lhis I ( ) ,1rtial c1omrnance
.
(b) compl alllpj ~f
(I ete d ec,r ,
c,pc11menl . Jdom1nance c) incom I cirtii
,(b) 'Tim experiment docs not follow the Prinuplc of p ete do nanc,
rti, 0.
Dominanlc. Which idea is depicted by a cross . rinr..
k) Pmk cnlom 111 F1 is due to incomplclr 2.3. bl b h , in wh <'11
generation resem es ot the parents, Ich 1~ !1
dominance.
1
~~?Y1heritance of one gene · q
(d) Ratio of F2 is .!._ (red) ·~(pink) · (while). t;)!t!!. ~o dominance
4 I l
(2019) (c) In complete do1:1inance rfl
1 1 (d) Complete dommance ~
16. The genotype~ ol a husband and wife are/ /fl and I i. f generation in a Mendelian cross sho (20
i\mong the blood t)11cs of their t.hilclren, how many 2 1• z d h typ . . wed th 13J
genotypic an p eno 1c ratios are sarne at¾1
d1flcrcnt genotn1cs and phenotypes arc possible? IL represents a case of as l 2}
~~~_).genotypes; 4 phenotypes
~ 4 genotypes; 3 phenotypes
(.:) 4 genotypes; 4 phenotypes
gi ;
(a) co-dominance
/ r h b
'd
.d .
(b) dihybrid c
.h
(c) monohy bn cross wit completed .
h .
ross
oni1na
~ mono y n cross wit mcomplete d .nee
(d) 3 genotypes; 3 phenotypes (2017) 1 orn,nanee
17. A tall true breeding garden pea plan~ is crossed with 20
A ~cross is carried out to ( 12
a dwarf true breeding garden pea plant. When tl:e 25
F1 plants were selfed the resulting genotypes were m ~ determine the genotype of a plant at F2
(b) predict whether two traits are linked
the ratio of
(a) 3 : I : : Tall: Dwarf (c) assess the number of alleles of a gene
(b)~: I : : Dwarf: Tall (d) determine whether two species or van t'
~ I : 2 : 1 : : Tall homozygous : Tall heterozygous : breed successfully. (Ma~'.es Will
. . '"' 20121
Dwarf 26. Test cross in plants or ill Drosophila involves cross '
(d) 1 : 2: 1 : : Tall heterozygous: Tall homozygous (a) between two genotypes with recessive trait IJJ~
: Dwarf. (NEET-I 2016) (b) yetween two F I hybrids
18. A gene showing co-dominance has ,.J..ee-Y the FI hybrid with a double :ecessive genotype
(a) alleles that are recessive to each other (d) between two genotypes with dominant trait
'-'-9Yboth alleles independently expressed in the (Mains 2011 ,
heterozygote 27 ABO blood groups in humans are controlled hyilie
(c) one allele dominant on the other gene I. It has three alleles - JA, 18 and i. Since there
(d) alleles tightly linked on the same chromosome. are three different alleles, six different genotypes are
(2015)
possible. How many phenotypes can occur?
19 Alleles are (a) ]Jiree (b) One
~ifferent molecular forms of a gene ~our (d) Two (20/0J
(b) heterozygotes .. ~ The genotype of a plant showing the dominant
(c) different phenotype
(d) true breeding homozygotes. (2015 Cancelled) phenotype can be determined by
(a) test cross (b) dihybrid cross
20 Multiple alleles are present (c) pedigree analysis (d) back cross. (2010!
~ t the same locus of the chromosome
(b) on non-sister chromatids 29. Which one of the following cannot be explained on
(c) on different chromosomes the basis of Mendel's law of dominance?
(d) at different loci on the same chromosome. (a) The discrete unit controlling a particular
(201 5 Cancelled) character is called a factor.
21. A man with blood group W marries a woman with (b) Out of one pair of factors one is dominant, and
blood group 'B'. What are all the possible blood the other recessive.
gr~s of their offspring? (c) Alleles do not show any blending and 411
\145 A, B, AB and 0 both the characters recover as such in f 2 [If
(b) 0 only
(c) A and B only
(d) A, Band AB only
G generation.
(d) Factors occur in pairs.
(2015 Cancelled) 30. ABO blood grouping is controlled by gene I which
(2010)
22. If two persons with 'AB' blood group marry and has three alleles and show co-dominance. 1hefl
have sufficiently large number of children, these are six genotypes. How many phenotypes in all afl
children could be classified as W blood group: possible?
, 39
heritance and Variation
esofIn (b) Three (b) 1 : 2 : 1
(a) 2: I
(d) 1 : 2. (1999)
(3l Sit
potlf (~) Five
(Mains20JO) (c) I : l
(cl ; n which an organism showing a dom· 4o A child's blood group is 'O'. The parent's blood
ssi-•· d • 1
Acrorype is crosse wit1
manl
1. t 1e recessive parent in groups cannot be {lJ)
(a) A and B (b) A and A r-,
'rnen° J<nOW its genotype lS called (c) AB and O (d) Band O. (1994)
~ertonohybrid cross (b) back cross
0
(al cross
(cl
;e~
(d) dihybrid cross.
(Mains 2010)
4 1. A child ofO-group has B-group father. The genotype
of father will be
(a) 1010 (b) JBJB (1992)
Mirirrhinum two plants with pink flowers were (c) JAJB (d) JBf>.
[11 ridized. The f 1 plants produced red, pink and
bl\ flowers in the proportion of 1 red, 2 pink and 42. An allele is dominant if it is expressed in
(a) both homozygous and heterozygous states
11·h1h·te. What could be the genotype of the two
l iv/ used for hybridisation? Red flower colour is (b) second generation
plaJl ~ined by RR and white by rr genes. ® (c) heterozygous combination (1992)
deter,,1 (b) RR IUJ (d) homozygous combination.
[c) rrrr
(a) Rr (d) rr -
(Mains 2010) 43 An organism with two identical alleles is
(a) dominant (b) hybrid
!JJ pea plants, yellow seeds are dominant to green. If · (c) heterozygous (d) homozygous. (1992)
· heterozygous yellow seeded plant 1s crossed with a
A man of A-blood group marries a woman of AB
a een seeded plant, what ratio of yellow and green
44. blood group. Which type of progeny
would indicate
~eded plants would you expect in FI generation,
that man is heterozygous A? (d) B (1991)
(a) 9: 1 (b) 1 : 3
(c) 3: 1 (d) 50: 50 (2007) (a) AB (b) A (c) 0
r
I _
crossingtest
(a)common
A to find
of one
Mstudying thesexual
F progeny with of
the genotype a hybrid
female is by
parent
2 behaviour of F progenies
45. Multiple alleles control inheritance of
(a) phenylketonuria (b) colour blindness
(c) crossing ofone F progeny with male I parent (c) sickle cell anaemia (d) blood groups. (1991 )
(di crossing of one F I progeny with male parent. 46. The contrasting pairs of factors in Mendeli an crosses
2 (2007) are called (b) allelomorphs
(a) multiple alleles
(d) paramorphs. (1991)
(c) alloloci
li. Test cross involves
trait between two genotypes with dominant
(a) crossing 47. Mendel's last law is
Mcrossing between two genotypes with recessive (a) segregation (b) dominance
trait (c) independent assortment
(cl crossing between two F, hybrids (d) polygenic inheritance. (1991)
Id) crossing the F, hybrid with a double recessive 48 Blue ey• colour is recessive to brown eye colour.
geootype. /2006) A brown eyed man whose mother was blue eyed
I [henotype of an organism is the result of marries a blue-eyed woman. The children will be
~
genotype and environment interactions (a) both blue eyed and brown eyed I : I
mutations and linkages (b) all brown eyed {ii)
(c) C)rtopl
Id) . asm,c · euects
tr and nutrition ( c) all bl ue eyed -
environmental changes and sexual dimorphism. (d) blue eyed and brown eyed 3 : I. (1991 )
1; A /2006) 49. RR (Red) Antirrhinum is crossed with white (WW)
1
, (a)ge.ne is said to. be dominant
1t express a if .
one · Offspnng RW are P'nk• Th is is an example of
(b) •t es its euect only in homozygous state (a) dominant-recessive
d" . es its
c1 express · euect
tr only in heterozygous (b) mcomp
· 1ete dominance
lei .on thon (c) hybrid (1991 )
. effect both in homozygous and
ithetexpresses its I (d) supplementary genes.
(d) it :;:~e:us
condition
presses its effect in any condition.
50. ABO blood group system is due to
1ac or m eritance
(a) mwti·c t · h
· When do . /2002) (b) incomplete dominance
l8
~ •her i~mant and recessive alleles express itself (c) multiple allelism (d) epistasis /
i'I
CO-do~scalled
c) an, h· mance (b) dominance ittl 51 . tt mates with Tl. What will b
offspring!
. . 1_990)
e charactenstic of
do a 75% recessive (b)
, (d)
nhyb P/ud1odomin_ ance
'di . mmance. ..
(2001) ( ) 25% rece .
(c) 50% recessive
l9 ,,,. n satio T
l • ss1ve (d) All d .
• t x tt gives rise to the progeny of 52. Haploids are able t ommant /1990)
0 dominant alleles/mu~a/xprebss both recessive and
ions ecause there are
4 Inheritance and
Variation
RA ndel's Laws of Inheritance ~rec n pod colour
1.1,,, ,v,e
~
(cl) Round seed shape (2003)
b low are two statements :
8. 1hr genes controlJing the seven pea characters
Gh'e~e:t I . Mendel studied seven pairs of
studied by Mendel are now knowri o be located on
State ting traits m pea plants and proposed the how many different chromoson ,ec 1
·ontras .
l
0
f inhentance. (a) Seven (b) jw
15
;a,itateltle nt II . Seven characters examined by Mendel
· (c) Five .._jaffour (2003)
S . xmeriment on pea plants were seed shape and
1n~e~ d h 9. According to Mendelism, which character shows
flower colour, po s ape and colour, flower dominance?
1
coour, h.h
position and stem e1gb t. (a) Terminal position of flower
the light of the a ove statements, choose the (b) Green colour in seed coat
In ct answer from the options given below : (c) }¼ink.led seeds
$Both Statement I and Statement II are correct ~ Green pod colour (2000)
1,) Both Statement I and Statement II are incorrect 10. First geneticist/father of genetics was
(c) Statement I is correct but Statement II is (a) De Vries (b) Mendel
mcorrect {ii) (c) Darwin (d) Morgan. (1991,
[d) Statement I is incorrect but Statement II - 11 . Which contribute to the success of Mendel?
is correct (2022) (a) Qualitative analysis of data
, How many true breeding pea plant varieties 'did (b) Observation of distinct inherited traits
Mendel select as pairs, which were similar except in (c) His knowledge of biology
one character with contrast~ traits? (d) Consideration ofone character at one time (1988)
(a) 4 (b) 2 u,e1"14 (d) 8 (2020)
3. Among the following characters, which on_ e was not 4.2 Inheritance of One Gene
considered by Mendel in his experiments on pea?
12. The production of gametes by the parents, formation
~richomes-Glandular or non-glandular ~ of zygotes, the F1 and F2 plants, can be understood
(b} Seed-Green or yellow (iJJ from a diagram called
(c} Pod-Inflated or constricted - (a) net square (b) bullet square
(d) Stem-Tall or dwarf (2017) (c) punch square ,J4' Punnett square (2021
4. Which one from those given below is the period for 13. In a cross between a male and female, both
Mendel's hybridisation experiments? heterozygous for sickle cell anaemia gene, what
(a) 1840-1850 (~)~ 857- 1869 percentage of the progeny will be diseased?
. (c) 1870-1877 \jJkJ 1856- 1863 (2017) (a) 100% 1
(b) _)0%
l. In his classic experiments on pea plants, Mendel did (c) 75% uaf 25% (2021)
not use
I 4. Identify the wrong statement with reference to the
;a) seed shape (b) flower position gene T that controls ABO blood groups.
c) seed colour ~ o d length. (201 5) (a) The gene (J) has three alleles. _
6, ij
t
many pairs of contrasting characters in pea
lain~ Were studied by Meng.pl in his experiments?
(b)_faPerson will have only two ot the three alleles.
# When JA and JB are present together,
( Eight \W) Seven they express same type of sugar. (
i, c) _Five (d) Six (2015 Cancelled) (d) Allele i does not produce any sugar.
~~h 0
ne of the following traits of garden pea
15. In Antirrhinum (Snapdragon), a red flower was
(2020)
9ie~ by Mendel was a recessive feature?
1 (b) ~al flower position
crossed with a white flower and in FI generation
reen seed colour all pink flowers were obtained. When pink flowers
,38 ~-tG- NEET-AIPMT Chapterwise Topicwise
So1ur
'A If blood group : 'B' 11 ) ood grou . ions ~: ,
"".ere selfed, the F) gene, at ion showed white, red ,,nd I . f . Pin
Modern teeI1mguc o protein elect I : 2.
'
prnk f1owcrs. l hoosc the incorrect s1,,1cmcnls from Jrcsencc of both 'A' and 'B' typ rophore,r· I t~
~h_c f<2!Jowing. I . cl . .d l . e Prot . ,~t 11,
blood group rn .1v1 ua s.1h1s in an CJc e1 0,, tn_ev11i
~aw ~)! segregation docs 1101 apply in lhis I ( ) ,1rtial c1omrnance
.
(b) compl alllpj ~f
(I ete d ec,r ,
c,pc11menl . Jdom1nance c) incom I cirtii
,(b) 'Tim experiment docs not follow the Prinuplc of p ete do nanc,
rti, 0.
Dominanlc. Which idea is depicted by a cross . rinr..
k) Pmk cnlom 111 F1 is due to incomplclr 2.3. bl b h , in wh <'11
generation resem es ot the parents, Ich 1~ !1
dominance.
1
~~?Y1heritance of one gene · q
(d) Ratio of F2 is .!._ (red) ·~(pink) · (while). t;)!t!!. ~o dominance
4 I l
(2019) (c) In complete do1:1inance rfl
1 1 (d) Complete dommance ~
16. The genotype~ ol a husband and wife are/ /fl and I i. f generation in a Mendelian cross sho (20
i\mong the blood t)11cs of their t.hilclren, how many 2 1• z d h typ . . wed th 13J
genotypic an p eno 1c ratios are sarne at¾1
d1flcrcnt genotn1cs and phenotypes arc possible? IL represents a case of as l 2}
~~~_).genotypes; 4 phenotypes
~ 4 genotypes; 3 phenotypes
(.:) 4 genotypes; 4 phenotypes
gi ;
(a) co-dominance
/ r h b
'd
.d .
(b) dihybrid c
.h
(c) monohy bn cross wit completed .
h .
ross
oni1na
~ mono y n cross wit mcomplete d .nee
(d) 3 genotypes; 3 phenotypes (2017) 1 orn,nanee
17. A tall true breeding garden pea plan~ is crossed with 20
A ~cross is carried out to ( 12
a dwarf true breeding garden pea plant. When tl:e 25
F1 plants were selfed the resulting genotypes were m ~ determine the genotype of a plant at F2
(b) predict whether two traits are linked
the ratio of
(a) 3 : I : : Tall: Dwarf (c) assess the number of alleles of a gene
(b)~: I : : Dwarf: Tall (d) determine whether two species or van t'
~ I : 2 : 1 : : Tall homozygous : Tall heterozygous : breed successfully. (Ma~'.es Will
. . '"' 20121
Dwarf 26. Test cross in plants or ill Drosophila involves cross '
(d) 1 : 2: 1 : : Tall heterozygous: Tall homozygous (a) between two genotypes with recessive trait IJJ~
: Dwarf. (NEET-I 2016) (b) yetween two F I hybrids
18. A gene showing co-dominance has ,.J..ee-Y the FI hybrid with a double :ecessive genotype
(a) alleles that are recessive to each other (d) between two genotypes with dominant trait
'-'-9Yboth alleles independently expressed in the (Mains 2011 ,
heterozygote 27 ABO blood groups in humans are controlled hyilie
(c) one allele dominant on the other gene I. It has three alleles - JA, 18 and i. Since there
(d) alleles tightly linked on the same chromosome. are three different alleles, six different genotypes are
(2015)
possible. How many phenotypes can occur?
19 Alleles are (a) ]Jiree (b) One
~ifferent molecular forms of a gene ~our (d) Two (20/0J
(b) heterozygotes .. ~ The genotype of a plant showing the dominant
(c) different phenotype
(d) true breeding homozygotes. (2015 Cancelled) phenotype can be determined by
(a) test cross (b) dihybrid cross
20 Multiple alleles are present (c) pedigree analysis (d) back cross. (2010!
~ t the same locus of the chromosome
(b) on non-sister chromatids 29. Which one of the following cannot be explained on
(c) on different chromosomes the basis of Mendel's law of dominance?
(d) at different loci on the same chromosome. (a) The discrete unit controlling a particular
(201 5 Cancelled) character is called a factor.
21. A man with blood group W marries a woman with (b) Out of one pair of factors one is dominant, and
blood group 'B'. What are all the possible blood the other recessive.
gr~s of their offspring? (c) Alleles do not show any blending and 411
\145 A, B, AB and 0 both the characters recover as such in f 2 [If
(b) 0 only
(c) A and B only
(d) A, Band AB only
G generation.
(d) Factors occur in pairs.
(2015 Cancelled) 30. ABO blood grouping is controlled by gene I which
(2010)
22. If two persons with 'AB' blood group marry and has three alleles and show co-dominance. 1hefl
have sufficiently large number of children, these are six genotypes. How many phenotypes in all afl
children could be classified as W blood group: possible?
, 39
heritance and Variation
esofIn (b) Three (b) 1 : 2 : 1
(a) 2: I
(d) 1 : 2. (1999)
(3l Sit
potlf (~) Five
(Mains20JO) (c) I : l
(cl ; n which an organism showing a dom· 4o A child's blood group is 'O'. The parent's blood
ssi-•· d • 1
Acrorype is crosse wit1
manl
1. t 1e recessive parent in groups cannot be {lJ)
(a) A and B (b) A and A r-,
'rnen° J<nOW its genotype lS called (c) AB and O (d) Band O. (1994)
~ertonohybrid cross (b) back cross
0
(al cross
(cl
;e~
(d) dihybrid cross.
(Mains 2010)
4 1. A child ofO-group has B-group father. The genotype
of father will be
(a) 1010 (b) JBJB (1992)
Mirirrhinum two plants with pink flowers were (c) JAJB (d) JBf>.
[11 ridized. The f 1 plants produced red, pink and
bl\ flowers in the proportion of 1 red, 2 pink and 42. An allele is dominant if it is expressed in
(a) both homozygous and heterozygous states
11·h1h·te. What could be the genotype of the two
l iv/ used for hybridisation? Red flower colour is (b) second generation
plaJl ~ined by RR and white by rr genes. ® (c) heterozygous combination (1992)
deter,,1 (b) RR IUJ (d) homozygous combination.
[c) rrrr
(a) Rr (d) rr -
(Mains 2010) 43 An organism with two identical alleles is
(a) dominant (b) hybrid
!JJ pea plants, yellow seeds are dominant to green. If · (c) heterozygous (d) homozygous. (1992)
· heterozygous yellow seeded plant 1s crossed with a
A man of A-blood group marries a woman of AB
a een seeded plant, what ratio of yellow and green
44. blood group. Which type of progeny
would indicate
~eded plants would you expect in FI generation,
that man is heterozygous A? (d) B (1991)
(a) 9: 1 (b) 1 : 3
(c) 3: 1 (d) 50: 50 (2007) (a) AB (b) A (c) 0
r
I _
crossingtest
(a)common
A to find
of one
Mstudying thesexual
F progeny with of
the genotype a hybrid
female is by
parent
2 behaviour of F progenies
45. Multiple alleles control inheritance of
(a) phenylketonuria (b) colour blindness
(c) crossing ofone F progeny with male I parent (c) sickle cell anaemia (d) blood groups. (1991 )
(di crossing of one F I progeny with male parent. 46. The contrasting pairs of factors in Mendeli an crosses
2 (2007) are called (b) allelomorphs
(a) multiple alleles
(d) paramorphs. (1991)
(c) alloloci
li. Test cross involves
trait between two genotypes with dominant
(a) crossing 47. Mendel's last law is
Mcrossing between two genotypes with recessive (a) segregation (b) dominance
trait (c) independent assortment
(cl crossing between two F, hybrids (d) polygenic inheritance. (1991)
Id) crossing the F, hybrid with a double recessive 48 Blue ey• colour is recessive to brown eye colour.
geootype. /2006) A brown eyed man whose mother was blue eyed
I [henotype of an organism is the result of marries a blue-eyed woman. The children will be
~
genotype and environment interactions (a) both blue eyed and brown eyed I : I
mutations and linkages (b) all brown eyed {ii)
(c) C)rtopl
Id) . asm,c · euects
tr and nutrition ( c) all bl ue eyed -
environmental changes and sexual dimorphism. (d) blue eyed and brown eyed 3 : I. (1991 )
1; A /2006) 49. RR (Red) Antirrhinum is crossed with white (WW)
1
, (a)ge.ne is said to. be dominant
1t express a if .
one · Offspnng RW are P'nk• Th is is an example of
(b) •t es its euect only in homozygous state (a) dominant-recessive
d" . es its
c1 express · euect
tr only in heterozygous (b) mcomp
· 1ete dominance
lei .on thon (c) hybrid (1991 )
. effect both in homozygous and
ithetexpresses its I (d) supplementary genes.
(d) it :;:~e:us
condition
presses its effect in any condition.
50. ABO blood group system is due to
1ac or m eritance
(a) mwti·c t · h
· When do . /2002) (b) incomplete dominance
l8
~ •her i~mant and recessive alleles express itself (c) multiple allelism (d) epistasis /
i'I
CO-do~scalled
c) an, h· mance (b) dominance ittl 51 . tt mates with Tl. What will b
offspring!
. . 1_990)
e charactenstic of
do a 75% recessive (b)
, (d)
nhyb P/ud1odomin_ ance
'di . mmance. ..
(2001) ( ) 25% rece .
(c) 50% recessive
l9 ,,,. n satio T
l • ss1ve (d) All d .
• t x tt gives rise to the progeny of 52. Haploids are able t ommant /1990)
0 dominant alleles/mu~a/xprebss both recessive and
ions ecause there are
