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
The trisomy for 21st chromosome is called
Down's syndrome
Turner's syndrome
Sickle cell anaemia
Klinfelter's syndrome
L- shaped chromosomes are also called
acrocentric
telocentric
sub- metacentric
None of these
C.
sub- metacentric
The shape of chromosome is determined by the position of centromere on the chromosomes. They may be of following five types:
(i) Acentric- centromere is absent.
(ii) Telocentric- centromere present at one end of chromosome.
(iii) Acrocentric- when chromosome is divided into a very small segment at one end and a very large segment on the other end.
(iv)Submetacentric- when chromosome has two unequal segments and forms V- shaped structure.
(v) Metacentric- two equal segments of chromosomes
If root of a flowering plant has 24 chromosomes, then its gamete has how many chromosomes?
24
12
4
8
Balbiani rings are the structural features of
allosomes
polytene chromosomes
autosomes
Lampbrush chromosomes
X- linked recessive gene is
always expressed in male
always expressed in femlae
lethal
sub- lethal
1 : 2 : 1 phenotypic and genotypic ratio is found in
complementary genes
blending inheritance
multiple alleles
pseudo alleles