Learning Mode - Zoology

Zoology

The offspring produced by outbreeding (cross between unrelated population) are found to be more superior than either of the parent. This superiority of the hybrid is known as:

A. Dominance
B. Heterosis
C. Xenia
D. Pleiotropism

Which one of the following characters in humans is not a autosomal recessive character?

A. Absence of sweat glands
B. Attached ear lobes
C. Glucoma
D. Sickle-cell anaemia

Which one of the following is not a sex-linked recessive character in humans?

A. Diabetes
B. Haemophilia
C. Xga blood group(+)
D. Colourblindness

Sex-determination in Dorsophila is governed by:

A. Y-chromosome
B. Y-chromosome and autosomes
C. X-Y-chromosomes
D. X-chromosomes and autosomes

In turner's syndrome, the phenotypic female has XO-genotype possesses:

A. 48 chromosomes
B. 47 chromosomes
C. 46 chromosomes
D. 45 chromosomes

In honey bee, the sex ratio of the offspring remains under the control of:

A. Diploid workers
B. Haploid workers
C. Diploid queens
D. Haploid drones

Haemophilia is caused by a sex-linked recessive gene located in the:

A. X-chromosome
B. Y-chromosome
C. Both X and Y chromosome
D. Autosome

In a case of gynandromorphism:

A. The phenotype is male while the genotype is female
B. The genotype is female but the phenotype is male
C. A part of the body is male while another part is female
D. Both the genotype and phenotype are male but the behaviour is that of female

In alleles for tallness by represented by 'T' and the allele for dwarfness by't', what will be the height of the offsprings (tall and dwarf) from crosses between Tt × tt, TT × Tt and Tt × Tt respectively?

A. 100% tall; 50% tall 50% dwarf; 75% tall and 25% dwarf
B. 100% tall; 75% tall 25% dwarf; 50% tall 50% dwarf
C. 50% tall 50% dwarf; 100% tall; 75% tall 25% dwarf
D. 75% tall 25% dwarf; 50% tall; 50% dwarf; 100% dwarf

In cattle, hornless condition (P) is dominant over horned (p). A certain bull is bred to three cows. With cow A which is horned, a hornless calf is produced; with cow B a horned calf is produced; with cow C which is hornless, a horned calf is produced. What are the genotype of cows A, B, C and the bull?

A. PP, Pp, PP,Pp
B. Pp, pp, Pp, pp
C. pp, pp, Pp, Pp
D. pp, pp, pp, Pp

Two sets of parents, Mr X and Mrs X, Mr Y and Mrs Y are claiming the same baby. Blood tests give information that Mr X And Mrs X belong to A group of blood and Mr Y belongs to O group while Mrs Y is of AB group. The child belongs to 'O'. To which parents should the child go?

A. Mr X and Mrs X
B. Mr Y and Mrs Y
C. It is not possible to decide as both the couple can have a child with 'O' group
D. None of these

The enzyme which can break and release one strand of DNA is:

A. Helicase
B. Ligase
C. Polymerase
D. Topiomerases

In rabbit black skin is dominant over brown skin and short hair is dominant over long hair. If homozygous black-short haired male is crossed with a homozygous brown-long haired female, the phenotype of F2 offspring will be in the ratio of:

A. Black short 1 : Brown long 1
B. Black long 3 : Brown short 1
C. Black short 9 : Black long 3 : Brown short 3 : Brown long 1
D. Black short 3 : Black long 1 : Brown short 3 : Brown long 1

A woman has a rare abnormality of eyelids called ptosis which depends on a single dominant gene (P). The woman's father had ptosis but her mother had normal eyelids. What are the probable genotypes of the woman, her mother and father respectively?

A. PP, Pp and pp
B. Pp, pp and PP
C. pp, Pp and Pp or PP
D. Pp, pp and Pp or PP

If a woman with normal colour vision and having married to a normal colour vision man and colour-blind father gives birth to children, then:

A. All of her sons are colour-blind
B. Half of the sons are colour-blind
C. All of her sons are with normal colour vision
D. None of these

A man with blood group A has a wife with blood group B. They have a child with blood group O. The other blood groups that can be expected in the future offspring of his couple are:

A. A group only
B. B group only
C. Both (a) and (b)
D. A, B and AB group

A haemophilic man marries a normal homozygous woman. What is the probability of their son and daughters being haemophilic respectively:

A. 100%, 50%
B. 50%, 0%
C. 0%, 50%
D. 0%, 0%

In the nucleus of resting cell of an XO female, there is:

A. No barr body
B. Two barr bodies
C. One barr body
D. Cannot be predicted

During mutagenesis, the information necessary to repair the damaged segment of the DNA is present in:

A. Proof-reading enzyme, DNA polymerase-I
B. A bus specific toposiomerase
C. The complementary strand
D. Undamaged neighbouring segments of the damaged strand itself

Erythroblastosis foetails can occur when:

A. Rh+ woman marries Rh man
B. Rh" woman marries Rh" man
C. Rh+ woman marries Rh+ man
D. Rh" woman marries Rh+ man

Human male who carries a sex-linked gene on the X-chromosome will transmit that gene to:

A. All of his sons
B. 50 percent of his sons
C. All of his daughters
D. 50 percent of his daughters

A pair of contrasting characters is termed as:

A. Allelomorphs
B. Heterozygous
C. Homozygous
D. Polymorphs

The ability of chemicals to induce mutation was first of all demonstrated by:

A. Auerbach and Robson
B. Flemming
C. Morgan
D. De Veris and Boveri

In auto fertilization, ______________ fuses with the egg nucleus:

A. Nucleus of bar body
B. Chromosome of egg cell
C. Nucleus of polar body
D. None of these

The genes which exclusively occur in Y-chromosomes are called:

A. Holandric genes
B. Autosomal genes
C. Z-linked genes
D. None of these