Pregnancy Genetics

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Pregnancy Genetics Powered By Docstoc
					Genetics & Heredity
Characteristics  that a
 child receives from both
   The study of the way humans pass
    characteristics on to their offspring such as:
           Eye  color
           Hair color

           Height

           Body build

           Blood types

           Intelligence

           Gender, etc.
   CELL: Basic unit of all living matter (Adult = over 10 trillion cells)

                                CYTOPLASM:            Substance of a cell outside of the nucleus

                                               NUCLEUS: Central point of cell /
                                               contains genetic coding for maintaining
                                               life systems and issuing commands for
                                               growth & reproduction

                                                     46 in each Nucleus (23 pairs)

                                                     GENES: bands on chromosomes
                                                     (thousands of genes)

                                                     DNA on genes (billions of DNA)
   How many chromosomes are there in
    EACH cell?
     46   CHROMOSOMES or 23 PAIRS

   How many chromosomes are in EACH
    reproductive cell?
     23   CHROMOSOMES
       Cell divides by copying the DNA - cell splits - new cell with
        normal number of chromosomes (Cell growth & repair)

       Creates 1/2 sets of chromosomes
       Women = 23        Men = 23         Combined = 46
 Female Sex Cells XX
 Male Sex Cells   XY

                 Baby Girl = XX
                 Baby Boy = XY

   Gender is determined by the father!
       More powerful - trait seen in person
       Upper Case Letter - A

       Weaker and hides in the background.
       Trait can only determine when two of them are present - may show
        up in future generations.
       Lower Case Letter - a
 Has   a recessive gene that is not visible

 Mother passes the   recessive X to son
    Color-blind male receives trait from his
    Mother is usually not color-blind
   B = BROWN eyes (dominate)        b = BLUE eyes (recessive)

   BB = BROWN eyes

   bb = BLUE eyes

   Bb = BROWN eyes but carry the recessive BLUE eye gene
 Female Reproductive System

Afemale is born with
thousands of partially formed
reproductive cells called ova,
or eggs
 Ova   are stored in ovaries
 Female Reproductive System

 Ovaries
 The female reproductive glands
 Produces female hormones
 Stores and releases ova
Female Reproductive System

  Ovulation
  When   an egg is released
   from the ovary and moves
   down the fallopian tube
 Female Reproductive System

 Fallopian   Tubes
 Two   tubes which connect the
   ovaries to the uterus and carry
   the egg to the uterus
 Female Reproductive System

 Uterus
 pear-shaped   organ where a
  child develops before birth
    Female Reproductive System
 Inside the uterus a lining of blood vessels
  and other tissue forms each month.
 During menstruation, the lining sheds,
  taking the released ovum with it.
 This cycle repeats about every 28 days
  throughout woman’s reproductive lifetime.
     about   40 years
 Female Reproductive System

 Menstruation
 Period—uterine  bleeding
 Shedding of the endometrium
 Female Reproductive System

 Cervix
 Neck or opening to the uterus
 Strongest muscle in the body
 Female Reproductive System

 Vagina
 Empty  passageway leading
  from the vaginal opening to the
               The most familiar female
                 reproductive organs
  Male Reproductive System
 Sperm
  Male  reproductive cells
  Males begin producing these microscopic
   cells at puberty
  A healthy male may produce sperm for the
   rest of his life
  Sperm originate in the testes
Male Reproductive System
 Testes

 Organs    in the scrotum
   that produce sperm and
  Male Reproductive System

 Vas   Deferens
 Two long    tubes that are a
   passageway and storage
   place for sperm
  Male Reproductive System
 Scrotum

 Sacs  that regulate
   temperature for
   sperm production
Male Reproductive System
 Semen

 A combination of sperm
  and fluid
Male Reproductive System
 Ejaculation

  Passage   of sperm
   and semen from
   the penis
Male Reproductive System
 Penis

  The  organ for
   reproduction and
Male Reproductive System

 Prostate   Gland
  Secretes an   alkaline fluid
   that neutralizes the acidity
                   Male Reproductive System
•The reproductive anatomy
of the male human is largely
•The male gonads, called
testes, hang in a sac of skin
called the scrotum.
•The testes produce sperm,
which cannot survive long at
body temperature.
•Sperm leave the body in
semen, a fluid produced by
the seminal vesicles.

Mi crosoft ® Encarta ® Encyclopedia 2002.
Male Reproductive System
    Four to five hundred
      million sperm,
surrounded by a protective,
 milky fluid called semen,
may be released at one time.
 Fertilization

  The  sperm penetrates
   the egg and a zygote is

Occurs when male and
   female reproductive
        cells unite
after sexual intercourse
   During intercourse, sperm is deposited in
    the vagina near the lower end of the uterus
   The sperm that enter the uterus quickly
    swim into the fallopian tubes. If an ovum is
    present, the sperm swarm the ovum and try
    to break through the surface.
   Only one sperm will be successful.
   At the moment of fertilization, the surface of
    the ovum seals out the remaining sperm,
    which eventually die.
 The fertilized ovum attaches to the
  uterine wall.
 The lining of blood vessels and
  other tissue remain to nourish the
  developing child until birth.
 Menstruation stops until the
  pregnancy is over.
                Review Conception
1. The ovary produces a egg
2. It travels down the fallopian tube
3. Fertilization begins when a
   single sperm cell unites with the
4. The fertilized cell divides into two
5. Divides into four--then eight, etc..
6. The clump of cells travel down
   the fallopian tube toward the
7 Two weeks after conception the
   fertilized ova is firmly planted in
   the uterine wall.
When Can Conception Occur?
 Conception can ONLY occur
   when a living ovum and
 sperm are in the same place
      at the same time
When Can Conception Occur?
 Deposited   sperm can live for
  four or five days in the female
 An ovum might typically
  survive for about 24 to 48
  hours in the female’s fallopian
When Can Conception Occur?

    Pregnancy can occur if
 intercourse takes place during
   the four or five days before
 the ovum is released and for
   about two days afterwards.
When Can Conception Occur?
   Time period is difficult
   to pinpoint
   Different for each woman
   Inconsistent cycles
   Stress & illness can cause
    the cycle to change
Can Pregnancy occur before a female has
     had her first menstrual period?

 Yes
  An   ovum can be released before
    the very first menstrual period
 Can pregnancy occur the first time a
      female has intercourse?

 Yes
 As   long as an ovum and sperm
  are present and unite
 It makes no difference whether
  it’s the first time
   Can pregnancy occur during
     the menstrual period?

 Yes
 The  ovum may be alive and
   present at this time
   Can pregnancy occur even if
    intercourse is incomplete?

 Yes
 A  few sperm may be released,
   and only one is needed
 Theuse of drugs, devices, or
 techniques to prevent pregnancy
            about contraception
 Information
 needs to come from reliable sources
 and be based on the facts about

   Having intercourse while standing up
    will not prevent pregnancy.

   Bathing or urinating after intercourse
    is not a prevention.
 No   sexual relations

 100%effective in preventing
 The   inability to conceive a child
        Multiple Births

   Fraternal Siblings
     Children  conceived from
      separate ova and sperm
     Born at the same time
     Different genetic makeup
         Multiple Births

   Identical Siblings
    A  single fertilized cell divides and
     Each separate cell develops into
      a baby
     Share the same arrangement of

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