Which one of the following statements about human sperm is correct?
Acrosome has a conical pointed structure used for piercing and penetrating the egg, resulting in fertilisation
The sperm lysis in the acrosome dissolve the egg envelope facilitating fertilization
Acrosome serves as a sensory structure leading the sperm towards the ovum
Acrosome serves as a sensory structure leading the sperm towards the ovum
B.
The sperm lysis in the acrosome dissolve the egg envelope facilitating fertilization
Penetration of human sperm is a chemical mechanism. In this, acrosome of sperm udergoes acrosomal reaction and release certain sperm lysins, which dissolves the egg envelope locally and makes the path for the penetration of sperm. Sperm lysins are acidic proteins. These sperm lysins contain a lytic enzyme hyaluronidase that dissolves the hyaluronic acid polymers in the intercellular spaces, which holds the granulosa cells of corona radiate together corona penetrating enzyme and acrosin.
The part of fallopian tube closest to the ovary is
isthmus
infundibulum
cervix
cervix
The signals for parturition originate from
placenta only
placenta as well as the fully developed foetus
oxytocin released from the maternal pituitary
oxytocin released from the maternal pituitary
The first movements of the foetus and appearance of hair on its head are usually observed during which month of pregnancy?
Fourth month
Fifth month
Sixth month
Sixth month
The second maturation division of the mammalian ovum occurs
shortly after ovulation before the ovum makes entry into the fallopian tube
until after the ovum has penetrated by a sperm
until the nucleus of the sperm has fused with that of the ovum
until the nucleus of the sperm has fused with that of the ovum
