1. Exploring Dominant and
Recessive Traits
Biology
CRHS Neistadt
Courtesy of Miss Smith

2. Questions to Think About
 Let’s list together any genetic traits
you can think of on the whiteboard.
• For example: eye color, hair color
 Where do traits come from?
 What do you think Dominant or
Recessive Traits are?

3. Where do traits come from?
 Your parents pass them down
through genetic traits.
 You receive half of your genes from
each parent
 Each person has about 70,000 pairs
of genes.
 Genes can be dominant or recessive

4. Dominant Traits vs.
Recessive Traits
 Dominant trait-Strongest trait
 Dominant trait-Masks or covers up
the weaker trait
• Which hair color do you think is
dominant?
• Which eye color do you think is
dominant?
• Which hair color do you think is
recessive?

5. Formal Definition
 Dominant Trait: the trait observed n
the first generation when parents
that have different traits are bred.
 Recessive Trait: a trait that
reappears in the second generation
after disappearing in the first
generation when parents with
different traits are bred.

6. Common Misconception
 Recessive Traits are not rare traits.
 Dominant or recessive traits may be
more common in a population.
 Example: Blonde hair is very
common in parts of Scandinavia.
 Example: The trait of having six
fingers on one hand is a dominant
trait!

7. Partner Time!
 Get with a partner.
 Complete the worksheet together having
your partner help you identify if you have
the traits listed.
 Put a check mark beside the trait you
have.
 We will share our results together at the
end!
 When you have completed the worksheet,
glue this page into your notebook. It
should go onto page 13.

8. Earlobe

9. Dimples

10. Tongue Roller

11. Freckles

12. Eyelashes

13. Hair Line

14. Hair Type

15. Hair Color

16. Eyes

17. Lips

18. Thumb

19. Skin Pigment

20. Vision

21. Tongue to Nose

22. Fingers
 Do you have hair on your knuckles?

23. Interlaced Fingers
 Without thinking about it, interlace
your fingers like the picture shows.
 If your left thumb is over your
right, then you have the dominant
trait.

24. Pinkie

25. Questions to think about
 Were traits that are dominant,
actually dominant among our
classmates?
 Is it possible to have traits that are
not visible in your parents?

26. If time permits:
 Glencoe Biology Text chapter 10
 Worksheet #49 & #17 from
Pacemaker Text: Chapter 5