Report 7: Human Heridity

INTRODUCTION

Human genetics is probably the oldest area applied genetics and homosapiens is certainly an important organism for genetic study, human genetic developed slowly until the last half century. Mendels’s principle, considerable interest was shown in human genetics. Many traits were found to be more prevalent in certain families than in the general population. A few conditions that result in mental retardation depend on single gene substitution and many types mental retardation are genetically and environmentally complex. Human inheritance appeared to be too imprecise and difficult analyze. It most easier and more productive to apply the experimental result method to other animals and plants. Controlled coating among experimental organism were preferred over uncertain human studies.

Identical twin and other combinations of multiple births provide the only human units that approach a genotype standard. When identical twins are separated early in life and experience different environment, one may compare the effect of these environments on similar genotypes. The life span of investigator is no greater than that of the organism being studied. Other difficulties encounter by human geneticist have been associated with incomplete knowledge of human cytology and the genetic mechanism.

Different genetic mechanism can produce identical phenotypes in different families. Polygenes resembles Mendelian genes in transmission but are cumulative in action. The emphasis in human genetic has been on phenotypes rather than genotypes. By contrast, certain manisfestations of a single gene may result strikingly different phenotypes. Different genetic mechanism can produce identical phenotype in different families. In spite of  these difficulties, significant advances have been made in human genetics, combining more traditional approaches with more recent advances in molecular genetics. Today investigation looks at the different aspects  and the role of genetics counselor in human genetics.

The ability to taste PTC (Phenylthiocarbamide) is always used in genetic population. This solution is just able to taste but not to drink, having the unusual property of either tasting very bitter, or being virtually tasteless, depending on genetic makeup of the tester.

LEARNING OUTCOME

We are able to

-          Test the ability of taste PTC

-          Analyze human different of their chromosome, either their genes is dominant or recessive.

-          Calculate the frequencies of phenotypes given student in your class.

METHODS

A.      THE ABILITY TO TASTE PTC

6 beaker was prepare by the instructor

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A piece of filter paper was tip in the beaker number 6 to determine whether or not you are a tester.

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Stop if already taste it

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If not, proceed to the next beaker.

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The number of beaker was record into table 1

B.      SOME READILY DETECTED HUMAN GENETIC TRAITS

Each characteristic was given and identify

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The percentage was calculate and record in a table 2.

BEAKER	NUMBER OF STUDENTS
	GROUP 1	GROUP 2	GROUP 3	GROUP 4	GROUP 5	GROUP 6	TOTAL
6	0	0	0	0	0	0	0
5	4	4	4	5	5	9	31
4	2	0	1	3	3	1	10
3	1	0	1	0	1	0	3
2	0	0	1	0	0	0	1
1	1	0	0	0	0	0	1
TASTELESS	0	0	0	1	0	0	1
TOTAL	8	4	7	9	9	10	47

CHARACTERISTICS	NUMBER OF STUDENTS	PERCENTAGES
The ability to fold tongue
Able to fold tongue [F_]	42	76.36%
Unable to fold tongue [ff]	13	23.63%
Ear lobe
Attached ear lobe [E_]	10	18.18%
Free ear lobe* [ee]	45	81.81%
Cheek
Dimple [D_]	6	10.9%
Smooth  [dd]	49	89%
Hair ‘whorl’
Clockwise [C_]	36	65.45%
Anticlockwise [cc]	19	34.54%
Hair line
Widow’s peak [P_]	12	21.81%
Straight hair line [pp]	43	78.18 %
Ear seruman
Dry ear seruman [W_]	19	34.55%
Wet ear seruman [ww]	36	65.45%

QUESTION AND ANSWER

1.     What is heredity?

Heredity is the heritance by the parent  during the fertilization of the gametes.

2.     Is the ability to taste PTC inherited?? If yes, how it can be inherited.

No

3.     What is the advantages to know whether are in dominant and recessive genotype.

The advantages is we can know the future offspring, predict the offspring and help in genetic analysis

4.     Differentiate between dominant  and recessive gene? Give some examples.

Dominant gene will appear over the recessive gene. The genotype of recessive allele are written in small letter while the dominant is the capital letter.

DISCUSSION

Some people in this world will not inherit the dominant gene only. From the experiment of the human genetic traits, I can observed most student are dominat to fold tongue. For ear lobe, the dominant have less number rather than the free ear lobe. This mean that the free ear lobe which is recessive have large number than the dominant  gene. For the cheek, the student who have dimple is dominant. As we all see, not all student have dimple. The recessive number which is smooth have large number. For the hair whorl, the clockwise hair whorl is dominant and the anticlockwise is recessive. The hairline widow is dominant but have small number then the straight line have the large number. Lastly the dry ear seruman is dominant over the recessive.

For the PTC result, most student are able to taste in the fifth beaker and also have a student that also cannot taste the PTC. Eventhough cannot taste the PTC, it doesn’t meant that the taste sense  is destroy. 

CONCLUSSION

As a conclusion, we are able to test the ability of taste PTC and also able to analyze human different of their chromosome, either their genes is dominant or recessive. Lastly we are able to calculate the frequencies of phenotypes given student.

REFERENCES

Brooker, R. J. (2009). Genetics Analysis & Principle. Third edition: Mc Graw Hill Companies Inc.

Campbell O.N. (2005). Biology. Seventh Edition: Benjamin Cumming.

Eldra P. S., Linda R. B. and  Diana W.M. (2005). Biology. Third Edition: Thomson Brooks/Cole.

Kenneth R. M.,and Joseph L. (2004). Prentice Hall Biology. Teacher's Edition: Pearson Publishing.