Which of the following is not vestigial in man ?
Tail vertebrae
Nails
Nictitating membrane
Vermiform appendix
The origin of kidney and ureter in Rana tigrina is :
all mesodermal
all endodermal
ectodermal and mesodermal
mesodermal and endodermal
A.
all mesodermal
Kidney and ureter in Rana tigrina is developed from mesodermal layer.
Embryonic cells differentiate at an early stage and form an outer layer of cells, the ectoderm and an inner layer the endoderm. At the later stage, the mesoderm is formed and these three germ layers give rise to all the tissues of the developing embryo.
Which of the following is not a case of epimorphosis ?
Formation of sperms from small clumps of cells
Regeneration of tail in a lizard
Replacement of severed arm in starfish
Replacement of limb in salamander
Which of the following steroid sex hormone influenced secondary sex organs?
Progesterone
Oestrogen
LH
LTH
An oocyte is released from the ovary under the influence of LH
after completing meiosis and before polar bodies are released
after completing meiosis I and before release of polar bodies
after completing meiosis
after completing meiosis I and after release of polar bodies.
Which of the following statement is wrong?
The Sertoli cells provide nutrition to the developing male germ cells
Leydig cells synthesize and secrete androgens
Secretions of the acrosome helps the sperm to enter into the cytoplasm of the ovum
Secondary spermatocytes are diploid
Secondary spermatocytes are diploid