CSS Zoology Questions & Answers - Set 15

1)   Who formulated chromosomal theory of inheritance:

a. Sutton
b. Morgan
c. Bateson
d. Johannsen
Answer  Explanation 

ANSWER: Sutton

Explanation:
No explanation is available for this question!


2)   A cross between F1 hybrids with either of the parent is called:

a. Back-cross
b. Test-cross
c. Reverse-cross
d. None of these
Answer  Explanation 

ANSWER: Back-cross

Explanation:
No explanation is available for this question!


3)   Which of these terms indicate a pair of contrasting characters or factors:

a. Allele
b. Phenotype
c. Homozygous
d. Heterozygous
Answer  Explanation 

ANSWER: Allele

Explanation:
No explanation is available for this question!


4)   In case red flower colour is dominant to white flower colour which of these statements is correct:

a. All red-flowered plants from red flowered plants
b. A few red-flowered plants from red-flowered plants
c. Ration of red-flowered plants from white-flowered hybrid plants is 1:1
d. Only white-flowered plants from white-flowered plants
Answer  Explanation 

ANSWER: Only white-flowered plants from white-flowered plants

Explanation:
No explanation is available for this question!


5)   Why pea plants were most suitable for Mendel's experiments than dogs because:

a. There were no pidegree records of dogs
b. Pea plants can be selfed
c. All pea plants have two number of chromosomes
d. Dogs have many genetic traits
Answer  Explanation 

ANSWER: Pea plants can be selfed

Explanation:
No explanation is available for this question!


6)   If opposite alleles come together, one of these only expresses while masking the other. It can be described as:

a. Law of independent assortment
b. Law of dominance
c. Law of segregation
d. Law of inheritance
Answer  Explanation 

ANSWER: Law of dominance

Explanation:
No explanation is available for this question!


7)   What will be the ration of plants in F2 generation when parents with tall stem (TT) are crossed with dwarf parents (tt):

a. 2 tall : 2 dwarf
b. 3 tall : 1 dwarf
c. 1 tall : 3 dwarf
d. None of these
Answer  Explanation 

ANSWER: 3 tall : 1 dwarf

Explanation:
No explanation is available for this question!


8)   Which will be the correct genotypes of F2 plants obtained by cross between tall (TT) and dwarf (tt) parents:

a. TT : tt : Tt : tt
b. TT : Tt : tt
c. 2 TT : 2 tt
d. None of these
Answer  Explanation 

ANSWER: TT : tt : Tt : tt

Explanation:
No explanation is available for this question!


9)   Phenotypic ration of F2 hybrids in cross between tall (TT) and dwarf (tt) plants is 3 Tall : 1 dwarf but genotypic ration will be:

a. 1 TT : 2Tt : 1tt
b. 2 TT : 2 tt
c. 1 TT : 1 Tt : 2 tt
d. None of these
Answer  Explanation 

ANSWER: 1 TT : 2Tt : 1tt

Explanation:
No explanation is available for this question!


10)   In a monohybrid cross between red plants (RR) and white plant the F1 hybrids (Rr) are all pink. It is indication of the fact that gene R is:

a. Mutant
b. Recessive
c. Incompletely dominant
d. Hybrid
Answer  Explanation 

ANSWER: Incompletely dominant

Explanation:
No explanation is available for this question!


11)   Visible characters in an organism are called:

a. Genotype
b. Phenotype
c. Homozygous
d. Heterozygous
Answer  Explanation 

ANSWER: Phenotype

Explanation:
No explanation is available for this question!


12)   Genotype of an organism is its:

a. Physical expression
b. Genetic consititution
c. Homozygous nature
d. Heterrozygous nature
Answer  Explanation 

ANSWER: Genetic consititution

Explanation:
No explanation is available for this question!


13)   In monohybrid cross between tall (TT) and dwarf (tt) parents F2 plants produced in the ration of 3 tall : 1 dwarf are:

a. Only in phenotype
b. Only in genotype
c. Both (a) & (b)
d. None of these
Answer  Explanation 

ANSWER: Only in phenotype

Explanation:
No explanation is available for this question!


14)   Two homologous genes are exactly similar in a genotype, which is:

a. Homozygous
b. Heterozygous
c. Hemizygous
d. None of these
Answer  Explanation 

ANSWER: Homozygous

Explanation:
No explanation is available for this question!


15)   Which of these is a heterozygous condition:

a. RR
b. Rr
c. rr
d. RRrr
Answer  Explanation 

ANSWER: Rr

Explanation:
No explanation is available for this question!


16)   A true breeding tall pea plant when crossed with a true breeding dwarf plant yielded tall plants in F1 generation which on selfing gives rise to 787 tall and 277 dwarf plant in F2 generation. The plants of F1 generation are:

a. Homozygous
b. Heterozygous
c. Hemizygous
d. None of these
Answer  Explanation 

ANSWER: Heterozygous

Explanation:
No explanation is available for this question!


17)   In a dihybrid cross between round yellow and wrinkled green plants the F2 generation will have 16 individuals in the ration of:

a. 9:3:3:1
b. 9:03:04
c. 9:3:1:3
d. 9:07
Answer  Explanation 

ANSWER: 9:3:3:1

Explanation:
No explanation is available for this question!


18)   In a cross between blue and white Andalusian fowls the results due to incomplete dominance will be:

a. 50% blue and 50% white fowls
b. 50% blue and 50% black fowls
c. 25% blue and 75% white fowls
d. 25% black and 75% white fowls
Answer  Explanation 

ANSWER: 50% blue and 50% white fowls

Explanation:
No explanation is available for this question!


19)   Microbial genetics is:

a. Genetics of plants
b. Genetics of animals
c. Genetics of man
d. Genetics of bacteria and viruses
Answer  Explanation 

ANSWER: Genetics of bacteria and viruses

Explanation:
No explanation is available for this question!


20)   A complete set of chromosomes, which is inherited as a unit from one parent is called:

a. Genotype
b. Genome
c. Gamete
d. Gene
Answer  Explanation 

ANSWER: Genome

Explanation:
No explanation is available for this question!


21)   A heterozygous individual which carries unexpressed recessive gene for a sex-linked character is known as:

a. Carrier
b. Mutant
c. Variant
d. None of these
Answer  Explanation 

ANSWER: Carrier

Explanation:
No explanation is available for this question!


22)   Hybridization in pre-mendelian era:

a. Did not take place
b. Was unsuccessful when attempted by workers
c. Did not result any effective change in nature
d. Occurred in nature but the phenomenon was not known
Answer  Explanation 

ANSWER: Was unsuccessful when attempted by workers

Explanation:
No explanation is available for this question!


23)   In which of the respect Mendel was lucky in selecting pea plants for his experiments in explaining laws of inheritance:

a. Pea plants belong to family leguminosae
b. Pea plants show red coloured flowers
c. Pea plants have large number of seeds
d. All the seven characters he selected were located upon different pairs of chromosomes
Answer  Explanation 

ANSWER: All the seven characters he selected were located upon different pairs of chromosomes

Explanation:
No explanation is available for this question!


24)   If F1 generation of a cross between tall and dwarf plants is of tall plants, it indicates the character to be:

a. Dominant
b. Recessive
c. Mutant
d. Sex linked
Answer  Explanation 

ANSWER: Dominant

Explanation:
No explanation is available for this question!


25)   The fact that F1 plants when backcrossed with double recessive parent gave four types of plants in equal proportions proves that the F1 plants produced:

a. Four type of gametes in equal number
b. Four types of gametes in ratio of 9:3:3:1
c. Two types of gametes in 3:1 ratio
d. Three types of gametes in 3:1:1 ratio
Answer  Explanation 

ANSWER: Four type of gametes in equal number

Explanation:
No explanation is available for this question!


26)   Mule is hybrid offspring of:

a. Male and female donkey
b. Female horse and male donkey
c. Male and female horse
d. None of these
Answer  Explanation 

ANSWER: Female horse and male donkey

Explanation:
No explanation is available for this question!


27)   Mule is an example of:

a. Heterosis
b. Hybrid vigour
c. Both (a) & (b)
d. None of these
Answer  Explanation 

ANSWER: Both (a) & (b)

Explanation:
No explanation is available for this question!


28)   The ratio of progeny of dwarf plants in a cross between heterozygous tall plant with homozygous dwarf plant will be:

a. 35%
b. 50%
c. 75%
d. 100%
Answer  Explanation 

ANSWER: 50%

Explanation:
No explanation is available for this question!


29)   Genetic complement is called:

a. Genotype
b. Phenotype
c. Alleles
d. None of these
Answer  Explanation 

ANSWER: Genotype

Explanation:
No explanation is available for this question!


30)   Who gave laws of segregation and dominance?

a. Mendel
b. Morgan
c. Malpighi
d. Muller
Answer  Explanation 

ANSWER: Mendel

Explanation:
No explanation is available for this question!


31)   Law of dominance states that:

a. Out of the two unit factors of contrasting expression of a trait present in an individual only one is expressed
b. Characters of parents are assorted independently during the gamete formation
c. Contrasting characters of parents are segregated at the time of gametogenesis
d. None of these things
Answer  Explanation 

ANSWER: Out of the two unit factors of contrasting expression of a trait present in an individual only one is expressed

Explanation:
No explanation is available for this question!


32)   The contrasting characters of individuals are represented by unit factors which separate at the time of gamete formation is explained by Meddel's law of:

a. Dominance and Recessiveness
b. Segregation
c. Independent Assortment
d. None of these
Answer  Explanation 

ANSWER: Dominance and Recessiveness

Explanation:
No explanation is available for this question!


33)   In cross between more than one pair of contrasting characters the assortment of unit factors is independent of parental combinations is the theme of:

a. Law of dominance and recessiiveness
b. Law of segregation
c. Law of independent assortment
d. None of these
Answer  Explanation 

ANSWER: Law of independent assortment

Explanation:
No explanation is available for this question!


34)   In Drosophila, red eye character is dominant over white-eye character. When a homozygous red eye individual is crossed with a homozygous white eye individual and individuals of F1 generation are intercrossed, 12 individuals are produced. White-eye individuals of these will be:

a. Three
b. Six
c. Nine
d. Twelve
Answer  Explanation 

ANSWER: Three

Explanation:
No explanation is available for this question!


35)   On the basis of which of these rations, we can prove law of independent assortment:

a. 9:3:3:1
b. 9:03:04
c. 1:02:01
d. 2:01:01
Answer  Explanation 

ANSWER: 9:3:3:1

Explanation:
No explanation is available for this question!


36)   Which of these is a recessive trait in Drosophila (fruit fly):

a. Red eye colour
b. White eye colour
c. Both (a) & (b)
d. None of these
Answer  Explanation 

ANSWER: Red eye colour

Explanation:
No explanation is available for this question!


37)   Skin colour inheritance in mammals is usually:

a. Monogenic
b. Multiple allelism
c. Polygenic
d. Pseudoallelism
Answer  Explanation 

ANSWER: Polygenic

Explanation:
No explanation is available for this question!


38)   A ratio of 3:1 in F2 individuals is suggestive of:

a. Monohybrid cross
b. Dihybrid cross
c. Trihybrid cross
d. None of these
Answer  Explanation 

ANSWER: Monohybrid cross

Explanation:
No explanation is available for this question!


39)   Ratio of 27:9:9:9:3:3:1 in F2 individuals is suggestive of:

a. Monohybrid cross
b. Dihybrid cross
c. Trihybrid cross
d. None of these
Answer  Explanation 

ANSWER: Trihybrid cross

Explanation:
No explanation is available for this question!


40)   Which of these do not follow mendelian ratios:

a. Complementary and supplementary genes
b. Lethal genes and incomplete dominance
c. Modifier genes
d. All of these
Answer  Explanation 

ANSWER: All of these

Explanation:
No explanation is available for this question!


41)   Segregation of alleles occurs at the time of:

a. Cleavage
b. Meiosis
c. Fertilization
d. Crossing over
Answer  Explanation 

ANSWER: Crossing over

Explanation:
No explanation is available for this question!


42)   Before proposing his theory, Mendel:

a. Had no idea of factors and genes
b. Had idea that all the factors are carried by genes
c. Had idea of chromoscmes but not the genes
d. Had no idea of chromosomes and genes
Answer  Explanation 

ANSWER: Had no idea of factors and genes

Explanation:
No explanation is available for this question!


43)   In man certain characters may be dominant and recessive. Which of these characters are dominant:

a. Colour blindness and haemophilia
b. Normal coloured vision and normal clotting
c. Testelessness to PTC
d. Attached ear lobes
Answer  Explanation 

ANSWER: Normal coloured vision and normal clotting

Explanation:
No explanation is available for this question!


44)   Out breeding in sheep produces improved strains of sheep which provide increased amount of meat and wool than in breeds. This is an example of:

a. Heterosis
b. Cross breeding
c. Inbreeding
d. All of these
Answer  Explanation 

ANSWER: Heterosis

Explanation:
No explanation is available for this question!


45)   When two pea plants with white flowers were crossed, F1 hybrids produced purple colour unlike their parents but like their remote ancestors, this is an example of:

a. Supplementary genes
b. Complementary genes
c. Lethal genes
d. Atavism
Answer  Explanation 

ANSWER: Atavism

Explanation:
No explanation is available for this question!


46)   Genes that reduce the viability of individual or cause its death of bearer are called:

a. Supplementary genes
b. Compementary genes
c. Lethal genes
d. None of these
Answer  Explanation 

ANSWER: Lethal genes

Explanation:
No explanation is available for this question!


47)   When red and white cattles are crossed, they produce a roan offspring which has both red and white hairs on skin, it is called:

a. Incomplete dominance
b. Codominance
c. Atavism
d. None of these
Answer  Explanation 

ANSWER: Codominance

Explanation:
No explanation is available for this question!


48)   Ratio of 9:3:4 is obtained instead of 9:3:3:1 under the condition when there is gene interaction involving:

a. Supplementary genes
b. Complementary genes
c. Both (a) & (b)
d. None of these
Answer  Explanation 

ANSWER: Supplementary genes

Explanation:
No explanation is available for this question!


49)   Instead of usual mendelian ratio of 9:3:3:1 often ratio of 9:7 is obtained in some of the crosses which is possibly due to interaction of:

a. Complementary genes
b. Supplementary genes
c. Modifier genes
d. None of these
Answer  Explanation 

ANSWER: Complementary genes

Explanation:
No explanation is available for this question!


50)   In a gene interaction the gene that masks the expression of another gene is termed:

a. Epistatic gene
b. Hypostatic gene
c. Both (a) & (b)
d. None of these
Answer  Explanation 

ANSWER: Epistatic gene

Explanation:
No explanation is available for this question!


51)   Allelic gene interaction is exhibited by which of these:

a. Incomplete dominance
b. Codominance
c. Lethal genes
d. All of these
Answer  Explanation 

ANSWER: All of these

Explanation:
No explanation is available for this question!


52)   Examples of non-allelic gene interaction are:

a. Complementary genes
b. Supplementary genes
c. Modifier genes
d. All of these
Answer  Explanation 

ANSWER: Complementary genes

Explanation:
No explanation is available for this question!


53)   Mating of closely related individuals is called:

a. Inbreeding
b. Out breeding
c. Atavism
d. None of these
Answer  Explanation 

ANSWER: Inbreeding

Explanation:
No explanation is available for this question!


54)   Which of these workers coined terms 'homozygous' and 'heterozygous' that we use very commonly in genetics:

a. Bateson
b. Saunders
c. Both (a) & (b)
d. None of these
Answer  Explanation 

ANSWER: Both (a) & (b)

Explanation:
No explanation is available for this question!


55)   Punnet devised a geometrical method for determining genetic combinations during crosses and know the possible expressions which is called:

a. Back-cross method
b. Test-cross method
c. Checker-board method
d. None of these
Answer  Explanation 

ANSWER: Checker-board method

Explanation:
No explanation is available for this question!


56)   Besides devising checker-board method Bateson is also known for:

a. Coining the term allelomorph for genes of contrasting expressions of characters
b. Coining terms 'genotype' and 'phenotype'
c. Describing gene interactions
d. None of these
Answer  Explanation 

ANSWER: Coining the term allelomorph for genes of contrasting expressions of characters

Explanation:
No explanation is available for this question!


57)   Protozoa were first discovered by:

a. Pasteur
b. Leeuwenhoek
c. Darwin
d. Kudo
Answer  Explanation 

ANSWER: Leeuwenhoek

Explanation:
No explanation is available for this question!


58)   First studied protozoa by Leeuwenhoek was:

a. Amoeba
b. Euglena
c. Vorticella
d. None of these
Answer  Explanation 

ANSWER: Vorticella

Explanation:
No explanation is available for this question!


59)   Name protozoa was given by:

a. Goldfuss
b. Hall
c. Jablot
d. None of these
Answer  Explanation 

ANSWER: Goldfuss

Explanation:
No explanation is available for this question!


60)   Who gave acellular concept for protozoans?

a. Dobell
b. Von Seibold
c. Cuvier
d. None of these
Answer  Explanation 

ANSWER: Dobell

Explanation:
No explanation is available for this question!