The number of characters investigated by Mendel was
four
seven
six
one
Correct Answer :
B. seven
Related Questions
A child is bom with an extra chromosome in each of its cells. This is usually the result of
nondisjunction
crossing over
segregation
hybridization
Among the following which is a test cross?
TtxTt
TTxTT
TTxTt
Ttxtt
Transfer of a gene or genes through a virus is called
transformation
transduction
genetic engineering
sex-duction
The nuclear membrane completely disappears during
late prophase
early metaphase
metaphase
interphase
The segment of DNA which participates in crossing over is known as
recon
muton
criston
replicon
How many meiosis will be required to produce 102 pollen-grains ?
25
25.6
26
26.5
The term 'meiosis' was coined bv
Herting and Van Beneden
Sutton and Boveri
Hofmeister and Waldeyer
Farmer and Moore
DNA duplication occurs in
meiosis only
meiosis II and mitosis
mitosis only
meiosis I and mitosis
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
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
Base substitutions from base analogues I are called
transitions
transversions
intragenic complimentation
intergenic complimentation
A functional unit of a gene which specifies synthesis of one poly-peptide is known as
clone
recon
cistron
codon
The best method to determine whether an individual is homozygous or heterozygous is
inbreeding
cross-breeding
back-crossing
self-fertilization
If an individual does not breed true for its characters, it is called
homozygote
allelomorph
hybrid
ecotype
Diakinesis is characterised by
crossing over
synapse
chiasmata
terminalization
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 giant chromosome having many chromo-nemata lying side by side all along their length is called
megachromosome
heterosome
polytene chromosome
super numerary chromosome
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.
Reverse transcription was discovered by
Watson
Crick
Temin
Porter
Dyad is
a pair of homologous chromosomes
a pair of non-homologous chromosomes
a pair of sister chromosomes
a pair of non-sister chromosomes
When is the sex of an offspring decided
At ovulation
During meiosis
During cleavage
At fertilization
In humans, an example of sex-linked trait is
Curly hair
Sickle-cell anaemia
Colour-blindness
Down's syndrome
Albinism in com plants is best described as
lethal
sex-linked
inbred
dominance
Colour blindness is caused due to
deficiency of vitamic C
sex-linked abnormality
absence of rods in retina
absence of visual purple in retina
A codon is a sequence of 3 nucleolides on
t-RNA
m-RNA
s-RNA
hn-RNA
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
The scientists who rediscovered the Mendel's laws are
Mast and Pantin
Watson and Crick
Corren, Tschermark and Hugo de Vries
Khorana and Nirenberg
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
The chromosomal theroy of heredity implies that
chromosomes are composed of DNA and protein
genes are composed of chromosomes
organism cannot live withoutchromosomes
genes are located on the chromosomes and are transmitted to the next generation through them.