Sexual Reproduction
Essay by review • March 1, 2011 • Essay • 522 Words (3 Pages) • 1,127 Views
sexual reproduction involves the fusion of teh nucleus of
an ovum(female sex cell)
with the nucleus of a sperm(male sex cell) in the fallopian tube
sperm
- elongated shape -> tail which allows sperm to swim
- little cytoplasm
- nucleus contains 23 chromosomes
-acrosome contains enzymes
ovum
- circular shape
- abundant cytoplasm
-- nucleus contains 23 chromosomes
FEMALE REPRODUCTIVE SYSTEM
- ovary -> releases an ovum every month during ovulation.
: releases sex hormones
(oestrogen & progesterone)
- fallopian tube: oviduct -> site of fertilization:
when the ovary releases an ovum, the
ovum is swept along the F.T by action of the cilia and rhythmic contractions of the muscle walls
uterus(womb) :
site where foetus develops during pregnancy: inner lining is
broken down and discharged once every 28 days during menstruation.
- cervix -> neck of the uterus
- vagina -> site where sperm are deposited during sexual intercourse
- vulva -> opening of the vagina
MALE REPRODUCTIVE SYSTEM
testis : produces spems continuously throughout life: produces sex hormone (testosterone)
scrotum: sac which holds testis outside body cavity as production of sperm requires
a temperature lower than body temperature
epididymis : stores sperm
sperm duct: transport sperm frm the coiled tube to teh urethra
sex glands (prostrate gland, cowper's gland, seminal vesicle) : releases fluid containing
nutrients needed for sperm; sperm + nutrient fluid = semen
urethra : transport semen or urine out of the body
penis: deposit sperm in the vagina during sexual intercourse.
a cycle of 4 stages occuring in a female once she reaches puberty
occurs generally over a period of 28 days
events are controlled by the actions of sex hormones
length of cycle varies frm female to female and it may be affected by stress, illness and diet
Stage 1: menstruation occurs ( day 0-5)
--breakdown and discharge of the uterine lining, blood and dead ovum tru vagina
stage 2: thickening of uterine lining (day 6-11)
stage 3: ovulation occurs during this period (day 12-16)
ovulation is the release of an ovum frm the ovary. therefore this is also
considered the fertile period (fertilization is most likely to be successful if sex occurs)
stage
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