THE RACE TO MAKE A BABY
SCIENCES: MIA COTHRAN MYP2
INTRODUCTION:
WHAT IS.REPRODUCTION
Reproduction or also known as procreation is the biological process by
which new "offspring" individual organisms are produced from their
"parents". Reproduction is a fundamental feature of all known life; each
individual organism exists as the result of reproduction.
WHAT IS A FOETUS ? & WHAT ARE THE STAGES OF DEVELOPMENT?
A fetus is a developing mammal. In humans, the
fetal stage of prenatal development which starts at
the beginning of the 11th week in gestational age
which is the 9th week after fertilization. Prenatal
development Prenatal or antenatal development is
the process in which a human fetus gestates during
pregnancy, from fertilization until birth. The
gestational age in embryology, gestational age is the
time elapsed since conception. This interval is also
termed fertilization age.
DESCRIPTION OF SPERM AND EGG CELL:
SPERM CELL:
The term sperm refers to the male reproductive cells in the
types of sexual reproduction known as an isogamy and zoogamy there is a
marked difference in the size of the gametes with the smaller one being
termed the "male" or sperm cell.
HOW DO SPERM AND EGG CELLS CONNECT?
Sperm cells cannot divide and have a limited life span, but after fusion with
egg cells during fertilization, a new organism begins developing, starting as
a totipotent zygote, which Sperm develops in the testicles.
THE JOB OF EACH OF THESE CELLS {SPERM & EGG}
SPERM CELL :
Basically, the duty of a sperm cell also known as the
spermatozoa is to find its way up the
female genital tract (vagina through the
cervix and into the uterus and up to the
fallopian tubes) to pierce the envelope
(outer covering) of the female egg. Once
this process occurs, fertilization occurs the process of a fetal human being
nurtured and developed.
Definition of fallopian tubes: The Fallopian tubes, also known as
oviducts are two very fine tubes lined with ciliated epithelia leading from
the ovaries of female mammals into the uterus by means of the utero –
tubal junction.
EGG CELL: The
egg is the sole provider of such
endosymbiosis organelles. In the
viviparous animals (which include humans
and all other placental mammals), the ovum
are fertilized inside the female body, and the
embryo then develop inside the uterus,
receiving nutrition directly from the mother.
So the EGG cell enables these events to occur.
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HOW DOES THE SHAPE OF THE EGG AND SPERM RELATE TO ITS JOB?
Each cell, within a function, is designed differently and the shape
also defines the work of the cell. The role of protein in the
formation and maintenance of the cell shape and the physical
dimensions of a cell largely relate to the kind of function
performed. In most organisms, the cell wall is observed as
responsible for the shape of the cells. Each cell is at somewhat
self-contained and self-maintaining in nature.
FERTILISATION AND IMPLANTATION:
FERTILISATION:
If the egg comes into commerce with sperm while it
descends the fallopian tubes on its way to the uterus,
fertilization may occur. The egg is covered in a thick
membrane, which the sperm must penetrate. Once inside
of the egg, a chemical reaction takes place to keep other
sperm from gaining entry. Meanwhile, the successful
sperm cell will lose its tail while its DNA packed head will fuse with the
nucleus of the egg.
IMPLANTATION:
Implantation, in reproduction is the entrance
of a fertilized egg to a surface in the
reproductive tract, usually to the uterine wall,
so that the egg may have a suitable
environment for growth and development
into a new offspring.
LABELLING EACH PARTS OF THE CELL :
SPERM CELL :
As you can see from the diagram , it
shows that the main parts of the sperm
cell are : head , midpiece , nucleus ,
centrioles ,& mitodrodia
EGG CELL :
When looking at the egg cell & sperm cell diagram you
will notice that each of them have a pivotal component ,
the nucleus. A nucleus contains most of the cell's
genetic material organized as multiple long linear
DNA molecules in complex with a large variety of
proteins, such as histones to form chromosomes.
WHY ARE THESE CELLS SO GOOD AT THEIR JOBS ?
Whilst sperm and egg cells are essential to the process of reproduction ;
we often wonder “ how are they so good at what they do?.” Starting with
the egg cell . It is good at what it does because not only does it supply
nutrients from the mother but , aids these occurrences to take place. When
looking at the sperm cell it allows the job of fertilization to take place.
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WHAT PART OF THE REPRODUCTIVE SYSTEM DOES EACH EVENT TAKE PLACE ?
The reproductive system or genital
system is a system of organs within an
organism which work together for the
purpose of reproduction. Some of the
most important parts of reproduction is
fertilization and implantation along with
many more.
THE MAJOR PARTS OF THE REPRODUCTIVE SYSTEM :
-UTERUS - THE WOMB FOR A FERTILISED EGG
-FALLOPIAN TUBES – CONNECT OVARIES AND UTERUS
-VAGINA- BIRTHING CANAL FOR CHILD BIRTH
-OVARIES – RELEASE THE EGGS.
-ACCESSORY GLANDS - THEY ARE MADE UP OF THREE ( 3)GLANDS THAT HELP TRSPORT
SPERM - SPERM AND EGG IS USED TO CREATE AN EMBRYO
SPERM
FALLOPIAN TUBES
REPRODUCTION –CELLULAR PROCESSES
One of the primary goals of all living creatures is to survive. To do so, cells
must be able to reproduce.
There
are several advantages to
reproduction over simply
sustaining the status quo. First,
reproduction allow a specie of
cells to
increase its population and
subsequently have a higher
competitive advantage.
Second, sexual reproduction
can
help to introduce genetic
variation into a specie which
can be
beneficial in the long run. One example of this genetic variation might be
the difference in looks between you and your parents.
Cells can reproduce in two ways, mitosis and
meiosis. In mitosis, the resulting daughter cell is an
identical clone of the original cell. Mitosis is mostly
used by somatic cells (cells of the body). Meiosis,
however, is a form of sexual reproduction and only
occurs in gametes (reproductive cells). The resulting
daughter cells have different genetic information
than their parent cells!
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Why Is Human Reproduction So Important?
Reproduction is crucial for the survival of all living things. Without a
mechanism for reproduction, life would come to an end.
Importance of Reproduction:
1. To create next generation. Unique property of a particular organism
is transferred from one generation to the next generation through
genes, which are situated in the DNA (Deoxyribonucleic Acid).
2. During Meiosis number of chromosomes become half of that in the
parent cells. As a result when both male and female gametes fuse
to form zygote, the number of chromosomes becomes adequate for
the species involved.
3. Every animal cell has fixed number of chromosomes. Human cell
contain 23 pairs or 46 chromosomes. After meiosis egg and sperm
cells contain 23 chromosomes. After zygote formation the number of
chromosomes is once again 23 pairs. This is necessary to maintain
the unique identity of a species.
4. To create variations in species. As no two individuals are same, so
genetic characters from both parents will help make a slightly
different copy of themselves. These small variations accumulate
over hundreds of years resulting in formation of new species.
5. New species facilitate evolution of organisms. Evolution is necessary
for survival as environmental conditions keep on changing from time
to time. As per Darwin nature has a method of selecting the best fit
species for survival.
Conclusion
To conclude my research on the many
mechanisms of reproduction it is safe to
say that not only is human reproduction
crucial for many generations to come
but consists of many cells etc. that
make up the development of the foetus.
In my eyes I think that not only does
reproduction contribute to animal
reproduction but creates variations of
species and facilitate evolution of
organisms.
BIBLIOGRAPHY:
http://www.bing.com/images/search?q=fetal+first+weeks+of+pregnancy&FORM=BIFD
http://www.babycenter.com/fetal-development-week-by-week
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http://startskins.com/5832256958/#
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m=QBIR&pq=fetal+first+week+of+pregnancy+with+diagram&sc=0-0&sp=-1&sk=
Stages of development :
Conception :
Fertilization and implantation occurs in the first stage
One month :
Your baby is an embryo consisting of two layers of
cells from which all her organs and body parts will
develop.
Second Month :
Your baby is now about the size of a kidney bean and is
constantly moving. He has distinct, slightly webbed fingers.
Three Months:
By now your baby is about 3 inches long and weighs nearly
an ounce. Her/his tiny, unique fingerprints are now in
place.
NEXT PAGE!
Four Months:
Your baby is now about 5 inches long and weighs 5 ounces. His
skeleton is starting to harden from rubbery cartilage to bone.
Five Months:
Eyebrows and eyelids are now in place. Your baby would now
be more than 10 inches long if you stretched out her legs
Six Months:
Your baby weighs about a pound and a half. His wrinkled skin
is starting to smooth out as he puts on baby fat.
Seven Months:
By now, your baby weighs about 3 pounds and is more than 15
inches long. She can open and close her eyes and follow a
light.
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Eight and nine months:
Your baby now weighs about 4 3/4 pounds. His layers of fat are filling
him out, making him rounder, and his lungs are well developed.
Nine months:
The average baby is more than 19 inches long and weighs nearly 7
pounds now, but babies vary widely in size at this stage!