Which one of the following statements with regard to embryonic development in humans is correct?
Cleavage divisions bring about considerable increase in the mass of protoplasm
In the second cleavage division, one of the two blastomeres usually divides a little sooner than the second
With more cleavage divisions, the resultant blastomeres become larger and large
Cleavage division results in a hollow ball of cells called morula
During a woman's life time, she produces about:
40-50 eggs
300-350 eggs
400-500 eggs
750-850 eggs
The production and maturation of sperm in testes is known as :
oogenesis
sporogenesis
gametogenesis
spermatogenesis
The phase of menstrual cycle in humans that lasts for 7-8 days, is :
menstruation
luteal phase
ovulatory phase
follicular phase
Which one of the following statement with regard to the embryonic development in humans is correct ?
Cleavage results in a hollow balls of cells called morula
Cleavage in mammalian ova is unequal holoblastic and horizontal
Rearrangement of blastomeres, a central cavity is formed inside the morula
Cleavage bring about considerable increase in the mass of protoplasm
Human sperm was discovered by
Leeuwenhoek
Aristotle
Graaf
Pander
A.
Leeuwenhoek
Sperm were first observed in 1677 by Antonie van Leeuwenhoek using a microscope, he described them as being animalcules (little animals), probably due to his belief in preformationism, which thought that each sperm contained a fully formed but small human.