Running head: THOUGHT PAPER: LIFE
Thought Paper: Life’s Greatest Miracle
Koni Christensen
Salt Lake Community College
Submitted as partial fulfillment for PSY 1100 Fall 2013
1
LIFE
2
Thought Paper: Life’s Greatest Miracle
Introduction: Genes
Humans, like all animals, reproduce sexually rather than asexually, a process by which
offspring is made from one parent. Sexual reproduction is so important because it allows for not
one, but two sets of different genes in each offspring. This is important for survival as a human
race for diversity between immune systems, otherwise one disease could wipe out the whole
race. This diversity in genes makes up the physical traits that make all of mostly exactly the
same, but it makes some of our traits different from one another, and this is diversity today. The
purpose of this paper is to give a quick summary of the film, Life’s Greatest Miracle, and to
reflect on my professional and personal perspective of prenatal development.
Summary: Life’s Greatest Miracle
Life’s Greatest Miracle is about reproduction and a baby growing inside a mother’s
womb. Sperm and egg cells are made in the testes and ovaries. Through Meiosis, each gamete
only has 23 chromosomes, no pairs, and has a random assortment of one type of each gene coded
in the DNA. Each gene comes from either the mother or father of the sperm/egg donor. The
movie depicts an in depth view of a sperm cell growing through meiosis in testis, and follows it
all the way in to the woman’s vagina through to her fallopian tubes all the way to the egg. Then
the sperm is absorbed into the egg where the structures holding DNA in the sperm cell are
dissolved and the genetic material is mixed with between the two cells. The egg starts dividing
LIFE
3
and then cells differentiate, and the baby starts to form. As the baby forms arm and leg buds
come out and the baby has a brain spinal cord, eyes, and sex organ buds that are physically the
same between a girl and a boy at this stage. Later on the Y chromosome has a cascade of events
that have to do with testosterone production in a boy will cause the buds to drop. Where they
would have stayed and become ovaries in a girl, they drop in a boy.
The baby’s only supply of nutrition and material to grow a human body comes from the
blood. Bones start out as cartilage, and after five months, the bones in the ear are developed, and
the baby can hear. In the last trimester of development in the womb, the baby is finishing
developing and developing fat reserves and neural impulses that will prepare the baby for the
outside world with functions they will use all the way in to adulthood. When a woman goes in to
labor the baby must fit through a small opening that will affect the baby’s scull structure. If the
birth canal is not large enough, the baby must be delivered by cesarean section.
Reflection: Personal and Professional Perspective
Today in biology class, I just asked my teacher how the reproductive organs, if they are
physically the same at this stage in development, develop in to male or female genitalia? He told
me that the genes in the Y chromosome are precursors for this cascading series of evens that lead
the reproductive organs to drop in to testis and for the clitoris to grow in to a penis. The growth
and appearance of male traits requires a certain amount of testosterone, too. So some
hermaphrodites will have a mutated copy of this SRY gene that causes the cascade of events of
growth and hormones in the sex organ region. This Nova series has gone perfectly with the last
couple of lectures in my human biology class about genes, DNA, and prenatal development.
It is amazing how complex conception all the way to development of a person is. It is all
up the chance, and there are endless combinations and possibilities of different people. It is
LIFE
4
amazing that we evolved to be the complex beings we are with complex mechanisms that make
us the functioning human beings we are. At the same time, it is also amazing that this mechanism
of reproducing genetic code is extremely simple. Easy combinations of A’s, T’s, C’s, and G’s
give our body the instructions for developing and living.
Conclusion
It is extremely interesting to know that we come from such a rare chance of a series of
events that cause all of us to be different. It can also teach us that we aren’t so different from
each other. We are all mostly genetically the same, and we develop the same as each other, too.
The advantage is that we can all come together and talk about the differences we have, and learn
more about us and the contrast in traits in comparison to others.
LIFE
References
Public Broadcasting System PBS NOVA (Producer). (2001). NOVA: Life’s greatest miracle.
[online presentation]. Available from http://www.pbs.org/wgbh/nova/body/life-greatestmiracle.html
Stassen-Berger, K (2014). Invitation to The Life Span (2nd ed.). New York, NY: Worth
Publishers.
5