IMPORTANCE OF FERTILIZATION

The time of conception can be regarded as one of the most important in a person’s life. The reason for this is that four very important conditions which have a great impact, both directly and indirectly, on the newly created individuals future development are determined at the time.

CONDITIONS

1. Heredity Endowment

The first important condition occurring at the time of conception, when the is fertilized by the spermatozoon, is the determination of the newly created individual’s heredity endowment. When the sperm unites with ovum, everything the newly conceived individual will ever inherit from parents, grant parents and other more remote ancestors is set. It has been estimated that there are between 40,000 to 60000 genes in the chromosomes in the mature mail cell and similar member in the mature ovum. This means that the newly created baby’s hereditary endowment contains between 80,000 and, 20,000 genes, each of which carries potentials for physical and mental traits.

Chance determines which of a vast number of possible combinations of characteristics the baby will inherit. As is true of chromosomes combinations from parents, it is entirely a matter of chance how many chromosomes from different ancestors on the maternal of paternal side will be passed down to a child. To produce a given kind of person a particular ovum must unite with particular sperm.

After conception, nothing can be done to add to, or subtract from the individuals hereditary endowment. If however, the mother establishes a favorable prenatal environment through good physical health and healthy attitudes, the chances of a favorable development of genes her unborn child already has will be greatly increased.

Some inherited characteristics, such as eye color and skin texture are relatively immune to environmental influences.





2.Sex Determination

The second important condition determined at the time of conception is whether the child will be male or female. For centuries, parents have tried to predict and control the sex of their unborn children. And, for centuries, there have been beliefs about how this could be done.

Modern scientific techniques for predicting the unborn child’s sex have included some tests:

1. The heart beat test:
Which maintains that a male fetus has a slower heart beat than female.

2. The smear test:
It is to determine the amount of the estrogenic and androgenic hormones present.

3. The saliva test:
It is to see if the mother’s saliva contains a chemical substance associated with a masculine fetus.


4. The amniotic fluid test:
Amniocentesis in a medical technique of extracting a sample of amniotic fluid from the uterus. Examination of the cells in this fluid has proved 100% accurate in predicting the of the unborn fetus.

CONTROL OF SEX:

Discovery of the sex chromosomes has shown that the factors that actually determine sex are internal and that the sex of the child is fixed at the time of fertilization. Of the chromosomes provided by the mature spermatozoon, one differs in character and structure from the others.

There are two kinds of chromosomes: the larger is X chromosome and the smaller one third the size of the X chromosome is the Y chromosome. One half of all mature spermatozoa carry the X chromosome and the other half carry the Y.

Thus, in any fertilized ovum there is always an X chromosome from the ovum and an X or a Y chromosome from the spermatozoon. If the spermatozoon that unites with the ovum is of the Y bearing type, the result will be an XY sex chromosome combination this always results in mail offspring. An X bearing spermatozoon unite with ovum the result will be an XX chromosome combination. This always produces a female offspring.

EFFECTS:
There are two effects direct and indirect effects:
Direct effect:
This direct effect of sex on development comes from hormonal conditions. Throughout the childhood years the sex organs of boys and girls produce sex hormones in small quantities. Mails produce more androgen, the female more estrogen.
Indirect effect:
This effect of sex on development come from environmental conditions. From the time children are born strong social pressures are put on them to confirm to the culturally approved pattern for their sexes.




Number of offspring

The third important condition determined at the time conception is whether the birth will single or multiple. The term “multiple birth “ refers to the birth of two or more babies within a few hours or days: twis, triplets, quadruplets,”single tons” are children who are born alone. They may have siblings-brothers and sisters- but the period of 9months or more separates their births from those of their siblings.

TWINS
There are two distinctly different types of twins.
Identical or uniovular or momnozygatic twins come from a single ovum fertilized by a single sperm and later it divides into two reason is not known. They resemble each other and they are of same sex.
Non-identical or biovular or fraternal or dizygotic twins are the product of two ova fertilized simultaneously. It is estimated tat one fourth of all twins are of the one –egg type. Why this seperation occurs, no one knows for certain, but there is some evidence that it is the result of hormonal disturbances. They are not identical, they born at a same time they can be 1 male and 1 female.
ORDINAL POSITION

The child’s position in a sequence of siblings is the fourth condition, determined at the time of conception, which has a profound influence on later development.
Scientific studies of ordinal position have revealed that environmental influences play a more important role than hereditary in determining the differences that have been found in children of different ordinal position in the family.
For example while there appears to be a decline in some abilities, especially intellectual abilities and achievements, there is evidence that this decline is due more to environmental factors than to hereditary.

CONDITIONS

1.Cultural ordinal position;
In cultures where the first born is regarded as the heir to authority, power, and wealth, parents brought in these culture will be influenced in the treatment of their children.



2. The attitude of significant people.
The attitudes of the children depend upon the attitudes shown by the family members. The younger children look upto the firstborns as models for themselves.

3. The role expectation.
If firstborns are expected to act as models for younger siblings, and tom take care of them, it affects firstborn’s attitudes toward themselves and their behavior.

BIBLIOGRAPHY

Hurlock B.Elizabeth. “Child development”, Tata McGraw-Hill publishing company ltd, New Delhi.


IMPORTANCE OF FERTILIZATION

TO
MRS.SHALINI
HOD OF PSYCHOLOGY

A ASSIGNMENT SUBMITTED IN PARTIAL FULFILLMENT OF THE COURSE IN PSYCHOLOGY

BY
IVTH GROUP


JULY-2007
MANGALORE