Short Answer TypeWrite the function of each one of the following:
(a) (Oviducal) Fimbriae
(b) Coleoptile
(c) Oxytocin
Long Answer TypeThe following is the illustration of the sequence of ovarian events (a to i) in a human female.
i) Identify the figure that illustrates ovulation and mention the stage of oogenesis it represents.
(ii) Name the ovarian hormone and the pituitary hormone that have caused the above mentioned event.
(iii) Explain the changes that occur in the uterus simultaneously in anticipation.
(iv) Write the difference between c and h.
(v) Draw a labeled sketch of the structure of a human ovum prior to fertilization.
How does the megaspore mother cell develop into 7-celled, 8 nucleate embryo sac in an angiosperm? Draw a labeled diagram of a mature embryo sac.
(a) Draw a labelled diagram of the human female reproductive system.
(b) Enumerate the events in the ovary of a human female during:
(i) Follicular phase
(ii) Luteal phase of menstrual cycle
(a) Write the specific location and the functions of the following cells in human males:
(i) Leydig cells
(ii) Sertoli cells
(iii) Primary spermatocyte
(b) Explain the role of any two accessory glands in human male reproductive system.
Short Answer TypeWhy are the human testes located outside the abdominal cavity? Name the pouch in which they are present.
Long Answer Type(a) Where does fertilization occur in human ? Explain the events that occur during this process.
(b) A couple where both husband and wife are producing functional gametes, but the wife is still unable to conceive, is seeking medical aid. Describe any one method that you can suggest to this couple to become happy parents.(a) Fertilization occur in the fallopian tube of females in human.
The events that occur during this process are :
i. The sperms come in contact with zona pellucida of the ovum.
ii. The sperm induces change in the membrane.
iii. Blocks entry of other sperms / ensures only one sperm fertilizes the ovum / prevents polyspermy.
iv. The secretion of acrosome helps the sperm to enter the cytoplasm of the ovum by degrading the wall of the ova.
v. Entry of sperm induces completion of second meiotic division forming ovum and 2nd polar body
vi. The haploid nucleus of Sperm and that of ovum fuses.
vii. Fertilisation completes on the formation of diploid Zygote.
b. Method suggested for the couple :
In vitro fertilisation followed by embryo transfer (ET)
In this method, popularly known as test tube baby programme, ova from the wife/donor (female) and sperms from the husband/donor (male) are collected and are induced to form zygote under simulated conditions in the laboratory
Short Answer TypeHow is the entry of only one sperm and not many ensured into an ovum during fertilisation in humans?
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