Human Hand Adaptations


Human Hand Adaptation

Introduction:        Living things have bodies that are adapted for the places they live and the things they do. Fish have gills so that they can remove oxygen that is dissolved in water. Most plants have green leaves which contain chlorophyll so that they can make food. Jellyfish have stinging cells to capture prey. Birds have hollow spongy bones so that they will be light enough to fly. Arctic animals have layers of fat and thick coats of fur to keep warm in the frigid Arctic climate. There are hundreds of examples of ways that organisms are adapted for a successful lifestyle.       Humans, too, are adapted for the things they do. One of our adaptations is our hand. Humans, as well as monkeys, gorillas, and other primates, have a hand that can grasp objects. We are able to grasp objects because of our opposable thumb. When students first hear or read about the opposable thumb during discussions of human evolution, they may perceive it as an anatomical fact with little seeming importance. In this activity, students will discover which of their simplest daily activities are possible only because of their opposable thumbs, which activities take longer without the use of an opposable thumb, and what sort of human activities would not be likely in the absence of an opposable thumb.   In this lab exercise, you will perform several common actions. Then you will change your hand so that it resembles that of a non-primate animal. You will determine whether or not you can successfully perform the same actions. This will demonstrate how the human hand is adapted for the actions it performs. You will work with a partner to do this exercise.   Materials: (per group)

  • masking tape
  • scissors
  • paper clips
  • zip-lock storage bag
  • plastic fork and knife
  • small amounts of food items to be cut
  • pencil
  • jar with screw-on lid
  • paper
  • roll of tape
  • balloons
  • comb
  • book
  • lace-up shoe
  • clock with a second hand
  • Piece of yarn or string
  • balloon
  • clothes with zippers & buttons

Procedure: Using masking tape, have your partner tightly tape each of your thumbs to the palm of the hand. Then, try to complete the tasks that are listed below. Be careful not to use your thumbs. Have your partner record on your data table how long it takes to do each task with your thumb taped and then with your thumb free. If an activity takes longer than 2 minutes, record the event as unsuccessful . After completing each item, write out the answers to the following questions:

  • Is the task more difficult with or without an opposable thumb?
  • How did you have to change your usual technique in order to complete this task?
  • Do you think organisms without opposable thumbs would carry out this task on a regular basis? Why or why not?


  1. Pick up a single piece of paper. Put it down on your desk.
  2. Pick up a pen or pencil from the table top. Use it to write your name on the piece of paper.
  3. Open a book. Turn single pages in the book.
  4. Unscrew a bottle cap or jar cover.
  5. Use a fork and knife to cut a food item into small pieces.
  6. Tear off a small piece of tape.
  7. Turn on the water faucet. (Complete activity #8!) Turn it off.
  8. Moisten a paper towel and wash and dry the desktop.
  9. Sharpen a pencil.
  10. Cut a circle out of a piece of paper using scissors.
  11. Pick up all the scraps from activity #10 and throw them into the recycling box.
  12. Comb your hair.
  13. Open a door.
  14. Pick up one paper clip. Clip a pile of papers together.
  15. Tie your shoelaces.
  16. Button several buttons.
  17. Zip up your jacket.
  18. Blow up a balloon and tie it.
  19. Tie a knot in a piece of string.
  20. Close a zip-lock bag.


Table 1 – Time It Took To Perform Various Tasks


TaskTime Taken for Event:Task Difficulty With Taped Thumb
Modification Made to complete Task
Thumb FreeThumb Taped
Pick up paper
Write name
Turn book pages
Open jar
Use knife & fork
Tear off tape
Turn faucet on & off
Clean desk top
Sharpen a pencil
Cut out a circle
Pick up the scraps of paper
Comb hair
Open door
Clip papers together
Tie shoelaces
Button & unbutton garment
Use zipper
Blow up & tie balloon
Knot string
Close zip-lock bag

Conclusion:   1. Explain why dog and cat paws are not adapted for doing the six actions you tested.     2. What are cat and dog paws adapted for?     3. Describe how your hand is adapted for doing the actions you tested.       4. You have an opposable thumb. Explain what this means.     5. Why do you feel that human hand adaptations have helped to make humans such a successful species on earth?


Ink Chromatography

Chromatography of Inks


One of the main jobs of biochemists is to unravel the complexities of chemical compounds and reduce them to their individual components.  The term chromatography comes from two Greek words, “chromat” meaning color and the word “graphon” meaning to write.  Separation of the components of chemical compounds can be done by using several methods. Liquids can be separate by High Performance liquid Chromatography (HPLC), while the components of gases are separated by Gas Chromatography.  Chromatography is a method for analyzing complex mixtures (such as ink) by separating them into the chemicals from which they are made. Chromatography is used to separate and identify all sorts of substances in police work. Drugs from narcotics to aspirin can be identified in urine and blood samples, often with the aid of chromatography.

Chromatography was first used to separate pigments (colors) in leaves, berries, and natural dyes. Paper chromatography is a technique used to separate, isolate, and identify chemical components of a compound. In paper chromatography, the solid surface is the cellulose fibers in the chromatography paper.  A solvent or developer (water, alcohol, or acetone) is placed in the bottom of the chromatography chamber. The paper acts as a wick to pull the solvent up the paper. The solvent front will “wick” up the chromatography paper by capillary action.  A minute drop of the ink or chemical mixture to be separated is placed near the bottom of the strip of chromatography paper, but slightly above the level of the solvent in the chamber.  As the solvent passes over the drop of ink, the components of the ink dissolve in the solvent. Because the components of the ink do not all dissolve at the same rate, as the components of the mixture move upward, they show up as colored streaks.  The separated substances on the chromatography paper form a color pattern called a chromatogram.

To determine the rate of migration for each pigment or component of the ink, the Rf value for each pigment must be calculated. The Rf value represents the ratio of the distance a pigment moved on the chromatogram relative to the  distance the solvent front moved. Each pigment or compound will have a unique Rf value that scientists can use to identify the substance. The Rf value is calculated using the following formula:

Rf = distance traveled by the compound / distance traveled by the solvent


Use the process of paper chromatography to separate the pigments in various markers and then determine the Rf value for each color on your chromatogram.


Plastic vials, paper clips, markers in assorted colors, chromatography paper, scissors, pencil


  1. Obtain chromatography vials and chromatography strips, and different color markers so that each person in the group will have two chromatograms.
  2. Cut one end of the chromatography strip to a point. The bottom of the point will mark the starting point for movement of the solvent (H2O).
  3. About 2.0 centimeters from the bottom of the strip, draw a faint horizontal line with pencil. This will mark the starting point for measuring the migration distance of each color.
  4. Using a different color marker for each strip, drop a dot of ink on the center of the horizontal pencil line.  Let this dry a moment & then add more ink to the dot.
  5. Add a small amount of water to the bottom of the chromatography chamber. (The ink dot should be ABOVE the surface of the water.)
  6. Straighten a paper clip and poke a hole through the top of your chromatography strip
  7. Use the paper clip to hang the strip in your chamber. (The straighten paper clip will lay across the top of the chamber.)
  9. Notice the separation of the ink as both the solvent and ink travel up the chromatography strip.
  10. Once the solvent front has neared the top of the strip, remove the strip from the chamber and lay it on a piece of paper towel.
  11. Immediately mark the solvent front with a faint pencil line.
  12. Immediately mark the leading edge of each color with an “x”.
  13. Measure, in millimeters, the distance the solvent migrated from the tip of the strip to your solvent front pencil line.
  14. Measure, in millimeters, the distance each color migrated from the point of origin (pencil line where the ink dot was placed) to the leading edge of the color (marked with an “x”.
  15. Record all data in Data table 1.
  16. Calculate and record the Rf value for each color using the formula below.

Rf = distance traveled by the compound / distance traveled by the solvent

Data Table 1


Color pen/marker used:

Separated colors
(list top of strip to bottom)
Distance each color traveled


Distance solvent (H2O)
Rf Value for each color

(Distance color traveled / Distance solvent traveled)





Color pen/marker used:

Separated colors
(list top of strip to bottom)
Distance each color traveled


Distance solvent (H2O)
Rf Value for each color

(Distance color traveled / Distance solvent traveled)





1. Which color of marker did you use?

2. which color separated out first from your ink dot?

3. Why did the inks separate?


4. What was your solvent?

5. If you had used markers that weren’t water-soluble, how would you have had to change this lab?


6. Why did some inks move a greater distance than others?


7. How do scientists use paper chromatography in their investigations?



Genetic Traits Activity


Finding Your Genetic Match


Have you ever noticed that brothers or sisters often look alike?  Their inherited traits are what make their physical appearance so similar. An inherited trait is a particular genetically determined characteristic that distinguishes a person. The traits of children are determined by the traits that  are passed on from their parents. Some traits are obvious in a family — a child’s nose is shaped like their mother’s nose, but some traits are less obvious. You may have similar traits to many of your classmates even though you are not related to them. Some examples of often un-noticed human traits are the ability or not to roll your tongue, attached or unattached earlobes, dimples or freckles, naturally curly or straight hair, hitchhiker’s or straight thumb, straight or widow’s peak hairline, smooth or cleft chin, or colorblindness or normal vision.

There are numerous traits in humans, but some traits occur more frequently than others.  Between 70-90% of the human population have free-hanging earlobes, can roll their tongue,  are right-handed, and can taste a chemical called PTC.  These traits are called high frequency traits.


Students will determine the presence of certain high frequency traits in themselves & their classmates.


Genetic Inventory sheet with pictures, paper, pencil, PTC taste strips.


  1. Identify which of the following 10 human traits you have by placing a check mark beside that trait.
  2. Compare the traits you have with other students in the classroom and find the student you most closely match.



Human Trait Inventory
Tongue Roller
Non-Tongue Roller
Attached Earlobes
Unattached earlobes
No Dimples
Widow’s Peak
Straight Hairline
Left Thumb on top when Hands Crossed
Right Thumb on top when Hands Crossed
Hair on mid-digit of hand
No hair on mid-digit of hand
Bent little finger
Straight little finger
Second toe longer than big toe
Second toe not longer than big toe
Can Taste PTC
Can Not Taste PTC
Vulcan (Fingers spread 2 by 2)
None Vulcan
Class Match:




Tongue RollerNon RollerDimplesNo Dimples
Attached EarlobesUnattached EarlobesWidow’s PeakStraight Hairline
Longer Second ToeShort Second ToeBent Little fingerHitchhiker’s Thumb
Attached Ear lobes (left)
Unattached ear Lobes (right)
“VULCAN” or No “VULCAN”DimplesRight/Left Thumb on top


Genetics PPT Questions



Mendelian Genetics
PowerPoint Questions
Gregor Mendel

1. Who is responsible for our laws of inheritance?

2. What organism did Mendel study?

3. When was Mendel’s work recognized?

4. When did Mendel perform his experiments & how many plants did he grow?

5. What did Mendel notice about offspring traits?

6. How is Mendel referred to today?

7. In what country did Mendel do his research on peas?

8. Mendel stated that physical traits were inherited as _______________.

9. Today we know that particles are actually what?


10. Define these three terms:
a. trait –


b. heredity –

c. genetics –


11. Name & describe two types of genetic crosses.



12. What is used to solve genetic crosses?

13. Sketch a Punnett square & show how they are  used to solve a genetics problems.




14. Use a Punnett square to solve a cross between two parents that both have the genotype Yy.





15. What are alleles & what are the two forms?


16. Explain the difference between dominant & recessive alleles.



17. Using a letter of the alphabet, show how each allele would be represented.


18. What is a genotype and write 3 possible genotypes?


19. What is a phenotype and write possible phenotypes for your genotypes in question 18?


20. Using these alleles, R = red flower and r = yellow flowers, write all possible genotypes & phenotypes.


21. What are homozygous genotypes?


22. Write a homozygous dominant genotype.

23. Write a homozygous recessive genotype.

24. What is meant by a heterozygous genotype?


25. Write a heterozygous genotype.

26. Heterozygous  genotypes are also called _____________.

27. What two things actually determine an organism’s characteristics?

Pea Experiments

28. Give 4 reasons that Mendel used garden peas, Pisum sativum, for his experiments.




29. Name the male and female parts of a flowering plant and explain how pollination occurs.



30. What is the difference between self and cross pollination?


31. Explain how Mendel cross pollinated his pea plants.



32. How did Mendel get pure plants?

33. Name 8 pea plant traits and give the dominant & recessive form of each.






34. How did Mendel’s experimental results compare to the theoretical genotypic ratios? Explain.


35. What does P1 mean?

36. What is the F1 generation?

37. What is the F2 generation?

38. What results from this cross — TT  x  tt?

39. What results do you get from crossing two hybrids (Tt   x  Tt)?


40. Show all your work for solving a P1 monohybrid cross for seed shape.

P1 cross:  __________ x __________

Genotype ____________
Phenotype ___________
G. Ratio _____________
P. Ratio _____________


41. The offspring of the above cross are called the _____ generation.

42. Show all your work for solving a F1 monohybrid cross for seed shape.

F1 cross:  __________ x __________

Genotype ____________
Phenotype ___________
G. Ratio _____________
P. Ratio _____________

43. Show all your work for solving both F2 monohybrid crosses for seed shape.


F2 cross:  ________ x ________  F2 cross:  ________ x ________





Genotype ____________                  Genotype ____________
Phenotype ___________                   Phenotype ___________
G. Ratio _____________                   G. Ratio _____________
P. Ratio _____________                    P. Ratio _____________

Mendel’s Laws

Complete the following question:

44. _________ are responsible for inherited traits.

45. Phenotype is based on _______________.

46. Each trait requires _____ genes, one from each ____________.

47. State the Law of Dominance and give an example.



48. State the Law of Segregation and tell when alleles are “recombined”.



49. State the Law of Independent assortment & tell what type of crosses show this.



50. Using the formula 2n where n = the number of heterozygotes, tell how many gametes will be produced by each of the following allele combinations:
a. RrYy
b. AaBbCCDd
c. MmNnOoPPQQRrssTtQq

51. What are the possible allele combinations in the egg and sperm from the following cross — RrYy x RrYy.


52. Show how to work an F1 dihybrid cross for seed shape & seed color.




F1 cross   __________ x __________




GR         Genotypes           PR         Phenotypes









53. Complete this cross or crosses for eye color & curliness of the hair — bbC__ x bbcc.





54. Draw a table summarizing Mendel’s 3 laws.







Incomplete and Co-Dominance

55. Incomplete dominance occurs in __________ and produces a phenotype _______________ the phenotype of the two parents.

56. Show your work solving a cross for flower color in snapdragons when there is incomplete dominance.


Cross:  RR x rr


Genotype ____________
Phenotype ___________
G. Ratio _____________
P. Ratio _____________

57. What is codominance & give an example?


58. Write the genotypes for each of these blood types:

type A
type B
type AB
type O

59. Solve this codominance problem: IBIB x IAi.




60. Solve this codominance problem for blood type: ii x IAIB.




Sex-Linked Traits

61. What are sex linked traits?


62. Name the sex chromosomes.

63. Write the genotype for male and for female.

64. Most sex-linked traits are carried on what chromosome?

65. Give an example of a sex-linked trait in fruit flies.

66. Show the results of crossing a red-eyed male (XRY)  with a white-eyed female (XrXr) fruit fly.
RR =
Rr =
rr =
XY =
XX =

Cross:    __________ x __________




Genotype ____________
Phenotype ___________
G. Ratio _____________
P. Ratio _____________

67. What is meant by a female carrier?


68. Name a disease that can be carried in this manner.




Genetics Worksheet Bi Chapter 9

 Fundamentals of Genetics

Section 9-1 Mendel’s Legacy

1. What scientist is responsible for our study of heredity?

2. Define heredity.

3. What plant did Mendel use for his hereditary experiments?

4. Name the 7 characteristics, giving both dominant and recessive forms of the pea plants, in Mendel’s experiments.

5. In order to study pea plant traits, Mendel had to control __________________ among the plants.

6. Define pollination & name 2 types.

7. How do pea plants normally pollinate?

8. How can cross-pollination of pea plants be done?

9. How did Mendel obtain pure pea plants?

10. What is the P1 generation? How is it obtained?

11. What is the F1 generation &how is it obtained?

12. How did Mendel obtain his F2 generation?

13. When Mendel crossed his P1 plants to get the F1 generation, what ratio did he get?

14. What is the difference between dominant & recessive genes?

15. State Mendel’s law of segregation.

16. What are alleles?

Section 9-2 Genetic Crosses

17 What is the difference between genotypes & phenotypes?

18. Write the 2 genotypes for a purple flower.

19. Write the genotype for a white flower.

20. What is the difference in a homozygous and a heterozygous genotype?

21. What is  probability & tell 3 ways they can be expressed.

22. What is the probability that you will get “heads” each time you flip a coin?

23. What is a monohybrid cross?

24. Give an example of a monohybrid cross.

25. What is a Punnett Square used for?

26. Sketch the Punnett Square for crossing a pure purple flower with a white flower.

27. Use a Punnett Square to solve this cross — PP x pp.

28. What percentage of the offspring from this cross are purple? White?

29. Use a Punnett Square to solve this cross in guinea pigs — BB x Bb. Hint: See page 174.

30. In the above cross, what coat colors & percents did you get?

31. What phenotype (coat color) would each of these guinea pig genotypes result in:

        a. Bb?

        b. BB?

        c. bb?

32. Use a Punnett Square to solve this cross for coat color in rabbits: Bb x Bb?

33. What percent of the rabbits will have black fur? Brown fur? What ratio does this give for coat color?

34. Define genotypic ratio.

35. What is the genotypic ratio for all F1 crosses (bb x Bb)?

36. Define phenotypic ratio.

37. What is the phenotypic ratio for all F1 crosses?

38. What is a testcross?

39. A testcross can determine which individual’s phenotype is ________________________.

40. Use a Punnett Square to solve the following 2 testcrosses:

        a. BB x Bb

        b. bb x Bb

41. In each of the above testcrosses, tell how many offspring have black coats (dominant) and how many will have brown (recessive) coats?

42. What does complete dominance mean?

43. Give an example of complete dominance in pea plants.

44. What is incomplete dominance?

45. How many alleles influence the phenotype in:

        a. complete dominance?

        b. incomplete dominance?

46. Using four-o-clocks, give an example of how incomplete dominance occurs. Be sure to tell all possible genotypes & phenotypes.

47. Give the following ratios for crossing 2 pink four-o-clocks (Rr x Rr):

        a. Genotypic ratio?

        b. Phenotypic ratio?

48. Define codominance.

49. In what genotype does codominance appear?

50. In horses, _________________ coat color is a result of codominance.

51. Write the genotype for roan coat color & tell the color of each allele in the genotype.

52. What is a dihybrid cross?

53. How many different genotypes will result in a dihybrid cross when 2 homozygous organisms are crossed?

54. The offspring from a dihybrid cross of 2 homozygous organisms will all be __________________________.

55. Use a Punnett Square to show the results of the following cross: RrYy x RrYy

56. How many different genotypes resulted from this cross?

57. How many different phenotypes resulted from this cross?

58. Write the genotypes for each of these phenotypes:

        a. Round, green seeds

        b. Wrinkled, yellow seeds

        c. Wrinkled, green seeds