Question

1) What are the two hypotheses of this experiment? What are you predictions for each hypotheses & briefly describe how you will test the given hypothesis and the one you generated.

2) What is a histogram AND why is it used for this lab instead of just plotting each individual's data?

3) Does the multi-year TRC (total ridge count) support each hypothesis? (explain your answer in terms of the shape and the position of the curve.)

4) What might account for differences between male and female TRCs (total ridge count)?

EXERCISE 8 - POLYGENIC INHERITANCI inheritance. This is a topics labo examine additive traits in polygenic main goal is to practice using additive The purpose of this laboratory is to examine additive This is a topics laboratory because the main goal is to and to model and interpret class data in a histogram. The inheritance of many human traits s follows a polygenic model meaning that mu the phenotypic expression of the trait. Fingerpri polygenic inheritance that can be quantified. as skin color, eye color, and height leaning that multiple gene loci are involved in determining of the trait. Fingerprint patterns are another example of The objectives of this laboratory are: 1. To practice additive trait calculations. 2. To collect and analyze class fingerprinting data. 3. To explore how the trait of total fingerprint ridge count inheritance. 4. To determine the differences between count. of total fingerprint ridge count illustrates polygenetic termine the differences between male and female average total ridge The hypothesis for this laboratory is that we wi Sis for this laboratory is that we will be able to 1) fingerprint ridge count is a polygenic trait, and 2) you should figure out the second hypothesis. Introduction Fingerprints and handprints have been used for thousands of years as a means of personal identification. Archaeological investigations have indicated that potters may have used these imprints to sign their work and that these imprints were viewed as marks of authenticity. In the 1850's, Sir William Herschel, a British administrator who worked in India, used friction ridge impressions as a means to control fraud in contracts and pension distributions. Sir Francis Galton looked at fingerprints in great detail and published a book in 1892, Finger Prints, which led to their use in criminal identification. The fingers, palms of the hands and the sole of the feet of humans have friction ridge skin. These areas are characterized by a complicated pattern of "hills and valleys." The hills are called ridges and the valleys are furrows. On the last joint of each finger, the friction ridge skin forms a number of basic patterns and within each basic pattern are many variations. Dermatoglyphics, a term coined in 1926 by Harold Cummins, is the study of the epidermal ridges but in practice includes other aspects of hand, finger, and footprints. The fingerprint patterns form early in embryonic development and remain at throughout the life of the individual. Fetal fingertip pads are observable around the sixth week of gestation and reach their maximal size by week 12 or 13 af ress, giving rise to elevated dermal ridges. Although the formation of the al ridge pattern and the total ridge count are polygenic, they are also influenced mental factors. Even identical twins, who come from the same fertilized egg e the same genetic makeup, have distinguishably different fingerprints. epidermal ridge pattern and th by environmental factors. Eve

Answer 1

1. The two hypothesis of the experiment are that-

a. fingertip ridge count is a polygenic trait i.e it is inherited in a polygenic inheritance pattern

b. fingertip ridge count remains constant throughout life and it differs from person to person. No two persons have exactly the same fingerprint count

The hypothesis can be tested by studying the fingerprint ridge pattern by inkpad method.

2. Histograms are bar graphs for a continous set of data. It shows the frequency on the y-axis. It is used when the data is continous for a given interval and that is how it is different from just plotting points on the graph. When the data is continous for a given set of intervals it is better to draw histogram than plot the data.

3. The total ridge count support the hypothesis that fingertip is a polygenic trait because it is not directly inherited from parents and does not follow Mendelian pattern. The fingertip pattern including the curves vary in each person, so the second hypothesis is also supported.

4. As males are usually taller and have a larger body than that of the females, the density of the ridges in larger surface area decreases. This accounts for the difference in ridge count in males and females.