Biology Questions and Answers

(Greg DeLong) #1

Biology Questions and Answers



  1. What is the relation
    between fecundation and the
    end of the meiotic process
    during oogenesis?


The oocyte Imeiotic division (interI only completrupted ates the second


metaphase) gamete occurs.if fecundation b (One can say thereforey a male (^)
that in fact the female gamete is the
oocyte II).



  1. What is the second polar
    body?


After terminatiodivision of the oocyte In of the second meioticI two cells are
generated: the egg cell proper and the
second polar bbody is a very small cell that almostody. The second polar
lacks cytoplasm and stays adnexal to


the egg cell. Tcontent of the oocyte he entire cytoplasmicII passes to the (^)
egg cell.



  1. What is the relationship
    between the menstrual cycle
    and ovulation?


Ovulation is the releasing of the female


gamete periodical event that occurs dufrom the ovary. Ovulation isring each a (^)
menstrual cycle. Considering as the first
day of the menstrualmenses begins, the ovulation cycle the day when occurs
around the 14th day when the
concentrations ofFSH reach high levels. the hormones LH and



  1. How does the male
    gamete penetrate the egg
    cell? How does the female
    gamete protect itself from the
    entrance of more gametes
    after the entrance of the first
    sperm cell?
    The sperm cell that reaches the egg cell
    process in wtriggers the acrosomhich hydrolytice reaction, enzymes oa^ f
    the acrosome are released on the


external su(the protective layer rface of the zona pellucidathat surrounds the (^)
egg cell). A portion of this layer is
digested ballowing the sperm cell to y the acrosomal enzymesreach the (^)
plasma membrane of the egg cell
carrying out fecundation.
At the moment that the sperm cell
makes contactmembrane a chemical alteration o with the egg cell (^) f this
membrane occurs. Enzymes secreted by
exocytosiszona pellucida (corticalunable to bind to other reaction) make the
sperm cells (zmale gametes cannonal reaction) anot enter the egg cell.d other



  1. What are the female
    pronucleus and the male
    pronucleus?


The female phaploid nucleus of the egg cell. Maleronucleus is the proper (^)
pronucleus is the haploid nucleus of the
sperm cell tcell. After fecundation bhat has fecundated the eggoth pronuclei
fuse forming the nucleus of the diploid
zygote.
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