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.
In human female, the blastocyst
forms placenta even before implantation
gets implanted into uterus three days after ovulation
gets nutrition from uterine endometrail secreation only after implantation
gets nutrition from uterine endometrail secreation only after implantation
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
Secretions from which one of the following are rich in fructose, calcium and some enzymes?
Male accessory glands
Liver
Pancreas
Pancreas
Vasa efferentia are the ductules leading from
testicular lobules to rete testis
rete testis to vas deferens
vas deferens to epididymis
vas deferens to epididymis
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
Seminal plasma in human males is rich in
fructose and calcium
glucose and calcium
DNA and testosterone
DNA and testosterone
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
Signal from fully developed foetus and placental ultimately lead to parturition which requires the release of
oestrogen fro placenta
oxytocin from maternal pituitary
oxytocin from foetal pituitary
oxytocin from foetal pituitary
