The term 'meiosis' was coined bv
Herting and Van Beneden
Sutton and Boveri
Hofmeister and Waldeyer
Farmer and Moore
Correct Answer :
D. Farmer and Moore
Related Questions
Mutations which are not dominant are not lost by a gene pooL This is known as
Survival of the dominant
Survival of the recessive
Hardly-Weinberg law
None of these
A codon is a sequence of 3 nucleolides on
t-RNA
m-RNA
s-RNA
hn-RNA
The crossing of a homozygous tall plant with a dwarf would yield plants in the ratio of
all heterozygous tall
two tall and two dwarf
one homozygous tall, two heterozygous tall and one homozygous dwarf
all homozygous dwarf.
Among the following which is a test cross?
TtxTt
TTxTT
TTxTt
Ttxtt
The science dealing with study of inheritance and variation is
Genetics
Evolution
Morphology
Cytology
The segment of DNA which participates in crossing over is known as
recon
muton
criston
replicon
In humans, an example of sex-linked trait is
Curly hair
Sickle-cell anaemia
Colour-blindness
Down's syndrome
Which disease results from the genetic inability to synthesize a single enzyme ?
Diabetes
Phenylketonuria
Colour-blindness
Down's syndrome
A chemical mutagen is
X-rays
UV-rays
-rays
5-Bromo-Uracil
A giant chromosome having many chromo-nemata lying side by side all along their length is called
megachromosome
heterosome
polytene chromosome
super numerary chromosome
Which one of the following chemical characteristics is not common to all living beings ?
Similar triplet codes for amino acids
Energy is stored by high energy rich phosphate bonds
Types of protein present in the body.
Ribosomes act at sites of protein synthesis
Chromosomes exhibit minimum coiling during
prophase
metaphase
interphase
telophase
Linkage is
directly related to crossing over
same as translocation
inversely related to crossing over
opposite to segregation
Reverse transcription was discovered by
Watson
Crick
Temin
Porter
An offspring of two homozygous parents different from one another by alleles at only one gene locus is known as
monohybrid
dihybrid
trihybrid
backcross
The best method to determine whether an individual is homozygous or heterozygous is
inbreeding
cross-breeding
back-crossing
self-fertilization
In a monohybrid cross the Fi ratio of a backcross is
1:1
3:1
1:2:1
9:3:3:3
Lethal genes are those which
cause the death of the organism in which they are present
cause the death of the homozygous infant being formed
cause the death of heterozygous infant being formed
all of the above
A pure tall pea plant was reared in a soil poor in nutrition and reached the size of a pure dwarf pea plant If the plant is selfed, the genotype in the Fi generation is most likely to be
all tall
50% tall and 50% dwarf
all dwarf
data insufficient
A colour-blind man marries the daughter of a colour-blind person. In their progeny
none of her daughters are colour-blind
all her sons are colour-blind
all her daughters are colour-blind
half of her sons are colour-blind
The number of characters investigated by Mendel was
four
seven
six
one
A functional unit of a gene which specifies synthesis of one poly-peptide is known as
clone
recon
cistron
codon
When two genes are situated very close to each other in a chromosome
the percentage of crossing over between themis high
hardly any cross-overs detected
no crossing-over can ever take place between them
only double cross overs can take place between them.
Exhibition of superiority by a hybrid over both of its parents is called
heterosis
hybridization
hypostasis
dominance
Crossing over in meiosis occurs in
leptotene
pachytene
diplotene
diakinesis
In the Operon concept, the regulator gene regulates chemical reactions in the cell by
inhibiting transcription of m-RNA
inactivating enzymes in the reaction
inhibiting the substrate in the reaction
inhibiting the migration of m-RNA into cytoplasm
A child is bom with an extra chromosome in each of its cells. This is usually the result of
nondisjunction
crossing over
segregation
hybridization
The genetic constitution of an organism is known as
Genome
Genepool
Genotype
Phenotype
The nuclear membrane completely disappears during
late prophase
early metaphase
metaphase
interphase
The condition in which only one allele of a pair is present is known as
Homozygous
Heterozygous
Hemizygous
Incomplete dominance