Exploring Hereditary Traits
OBJECTIVE: To determine your possible genotypes for some inherited traits.
MATERIALS; Pencil, Ruler, Paper
PROCEDURE:
Make a table with three columns “Trait”, Your Phenotype”, and “Your Possible Genotypes”.
In the first column write down the bold terms from the sample table.
In the second column write down whether or not you possess that trait (Ability to Roll Tongue, Present or Absent, Blue Eyes, etc.)
In the third column write down your possible genotype for each trait using the appropriate symbols.
ANALYSIS:
-
Compare your traits with those of your classmates. Which trait or traits are most common among your classmates?
-
Which observations are evidence that the most common trait may not be determined by the dominant allele?
-
Which dominant alleles studied today were most common?
-
What factors should be considered before comparing the frequency of traits in the classroom with their frequency in the U.S. population?
- Here are some descriptions of the traits being studied:
-
Tongue Rolling (R ) : Stick out your tongue and try to roll up the sides so that the tongue forms a U-shape.
-
Free Earlobe (F): the lobe of the ear hangs freely below the point of attachment to the head.
-
Widow’s Peak (W): The midpoint of the hairline along the front of the forehead points downward.
-
Straight Thumb (J): When extended from the palm of the hand, the top segment of the thumb forms a straight line with the bottom segment (AKA “Hitchhiker’s Thumb”).
-
Bent Little Finger (S): The last segment of the little finger bends in toward the ring finger.
-
Left-over-right Thumb Crossing (L): When the hands are folded in a natural fashion, the left thumb crosses over the right.
-
Chin Cleft (C): The center of the chin has an indentation resembling a deep dimple.
-
Mid-digital Hair (F): Hair is present on the middle section of any finger.
-
Short Big Toe (T): The big toe is shorter than the second toe.
CONCLUSION:
Write a paragraph using the following vocabulary correctly:
genotypes, phenotypes, dominant, recessive, heterozygous, homozygous