CBSE
Multiple Choice QuestionsWhich of the following is a test cross?
Tt tt
TT tt
Tt Tt
tt tt
Pure tall plants are crossed with pure dwarf plants. In the F1 generation, all plants were tall. These tall plants of F1 generation were selfed and the ratio of tall to dwarf plants obtained was 3 : 1. This is called
dominance
inheritance
codominance
heredity
1 : 2 : 1 phenotypic and genotypic ratio is found in
complementary genes
blending inheritance
multiple alleles
pseudo alleles
X- linked recessive gene is
always expressed in male
always expressed in femlae
lethal
sub- lethal
Chromosome complement with 2n - 1 is called
monosomy
nullisomy
trisomy
tetrasomy
Balbiani rings are the structural features of
allosomes
polytene chromosomes
autosomes
Lampbrush chromosomes
If root of a flowering plant has 24 chromosomes, then its gamete has how many chromosomes?
24
12
4
8
The trisomy for 21st chromosome is called
Down's syndrome
Turner's syndrome
Sickle cell anaemia
Klinfelter's syndrome
Chromosome complement with 2n - 1 is called
monosomy
nullisomy
trisomy
tetrasomy
L- shaped chromosomes are also called
acrocentric
telocentric
sub- metacentric
None of these
