During meiosis crossing over occurs at
pachytene
zygotene
leptotene
diakinesis
A.
pachytene
During pachytene stage, crossing over takes place. It is exchange of equal segments of non-sister chromatids belonging to homologous chromosomes. The chromosome pair (i.e. bivalent) consists of four chromatids and thus crossing over takes place at four stranded stage.
The hormone which stimulates constriction of gall bladder
gastrin
secretin
glucagon
cholecystokinin
Eustachian canal connects
middle ear with external ear
middle ear with internal ear
external ear with internal ear
pharynx with middle ear
A man of 'A' blood group marries a woman of 'AB' blood group, which type of progeny would indicate that man is heterozygous ?
O
B
A
AB