17970.Which of the followings is a well known autosomal abnormality at birth?
Klinefelter syndrome
Patau syndrome
Down syndrome
Turner syndrome
17971.The genotype of a plant showing the dominant phenotype can be determined by
Back cross
Test cross
Dihybrid cross
Pedigree analysis
17972.Mendel's principle of segregation means that the germ cells always receive
One pair of alleles
One quarter of the genes
One of the paired alleles
Any pair of alleles
17973.What is the composite display (paired and arranged according to size) of all the chromosomes of an organism called?
Linotype
Karyotype
Phenotype
Chromotype
17974.Mating of an organism to a double recessive in order to determine whether it is homozygous or heterozygous for a character under consideration is called
reciprocal cross
test cross
dihybrid cross
back cross
17975.In blood group typing in human, if an allele contributed by one parent is IA and an allele contributed by the other parent is i, the resulting blood group of the offspring will be
A
B
AB
O
17976.Phenotype of an organism is the result of
Environmental changes and sexual dimorphism
Cytoplasmic effects and nutrition
Mutations and linkages
Genotype and environment interactions
17977.Excessive growth of hair on the pinna is a feature found only in males because
The gene responsible for the character is recessive in females and dominant only in males
The character is induced in males as males produce testosterone
The female sex hormone estrogen suppresses the character in females
The gene responsible for the character is present on the Y chromosome only
17978.The genotype is called a ______ when a person is heterozygous at two different loci.
Trihybrid
Dihybrid
Monohybrid
Mutant
17980.The genetic defect-adenosine deaminase (ADA) deficiency may be cured permanently by
Enzyme replacement therapy
Periodic infusion of genetically engineered lymphocytes having functional ADA cDNA
Administering adenosine deaminase activators
Introducing bone marrow cells producing ADA into cells at early embryonic stages
17981.When the effects of both alleles are equally expressed in the heterozygote which one of the followings occurs?
Segregation
Codominance
Pleiotropy
Incomplete dominance
17982.When a tall plant with round seeds (TTRR) crossed with a dwarf plant with wrinkle seeds (ttrr). The F1 generation consists of tall plants with round seeds. What would be the proportion of dwarf plant with wrinkle seeds in F1 generation?
0
1/2
1/4
1/16
17983.An individual who has two different alleles of a gene is called ______.
Allelopathic
Homozygous
Heterozygous
Codominant
17984.Nondisjunction may occur due to the failure of ______ chromosomes to separate properly in meiosis I.
Defective
Heterozygous
Homologous
Autosomal
17985.Haploids are more suitable for mutation studies than the diploids. This is because
All mutations, whether dominant or recessive are expressed in haploids
Haploids are reproductively more stable than diploids
Mutagens penetrate in haploids more effectively than is diploids
Haploids are more abundant in nature than diploids
17986.Which one of the followings is caused by a recessive allele of a gene on chromosome 7?
Phenylketonuria (PKU)
Tay-Sachs disease
Cystic fibrosis (CF)
Huntington disease
17987.ABO blood groups in humans are controlled by the gene l. It has three alleles – lA, lB and i. Since there are three different alleles, six different genotypes are possible. How many phenotypes can occur?
Two
Three
One
Four
17988.During meiosis I, the ______ chromosomes of each pair come together to lie side by side.
Homologous
Homozygous
Heterozygous
Linked
17989.______ are heterozygous with regard to only one pair of alleles.
Testcrosses
Dihybrids
Monohybrids
None of these