1. Mendel and Inheritance of Traits Notes

2. traits offspring genes
Heredity: passing of _______ from parent to ___________
● Trait: ________________ that an organism can pass to its offspring through _______.
traits
offspring
characteristic
genes

3. 2) Genetics: the study of how traits are ___________ through the actions of alleles
inherited

4. 3) Gregor Mendel: the _______ of modern genetics
Used ____ _______ to study how traits are passed from parents to offspring
father
pea
plants

5. First Experiment: Crossed purebred ____ plants with purebred _______ plants
tall
short
This plant is purebred tall.
This plant is purebred short.

6. Results: _____- generation were ___ ____ plants (no short)
first
all
tall

7. self Second Experiment: first-generation ____ plants _____- pollinate
tall
self

8. second tall short three tall one short 1 2 3 1
Results: _________- generation plants were _____ and _______
There were _______ _____ plants for every _____ _______ plant
(a 3:1 ratio).
second
tall
short
three
tall
one
short 1 2 3 1

9. predict traits dominant
Determined we can _________ _______ of offspring based on the parents’ traits
Figured out ___________ and recessive alleles
predict
traits
dominant
dominant
recessive

10. chromosome 4) Gene: section of DNA on a
________________ that directs the making of a specific ________ .
chromosome
protein
Each gene codes for 1 protein

11. An organism’s genes are inherited from its _________.
parents

12. 5) Allele: the different forms a ______ may have for a trait
gene

13. Alleles can be ___________ or ___________ dominant recessive
Dominant alleles
Recessive alleles

14. Dominant: ________ up or masks the ___________
Dominant: ________ up or masks the ___________. We only see the dominant trait.
Use _________ letters to represent dominant traits. Ex: T or P
covers
recessive
capital

15. *Both parents recessive alleles are hidden by the dominant.
Recessive: ________ by the dominant allele. We only see if ______ ________ for the trait are ___________.
hidden
both
alleles
recessive
*Both parents recessive alleles are hidden by the dominant.
Use _______ case letters to represent recessive traits Ex: t or p
lower
CF=cystic fibrosis

16. 6) Genotype: the genetic __________ of an organism (its alleles)
It is written with letters such as ___ or ___ or ___
make-up TT Tt tt

17. tt TT Homozygous: having two ________ that are the _______ for a trait
Example: ___ or ___
alleles
same TT tt

18. Tt Heterozygous: having two __________ alleles for a trait different
Example: ___
different Tt

19. Dominant Genes
Recessive Genes
Genotype: AA or Aa
Genotype: aa

20. 7) Phenotype: the __________ expression of a particular ___________
It is what a ______ looks like
Example: blue eyes, _____ _________, tall plants, etc.
physical
genotype
trait
red
flowers

21. Phenotype: Brown/Black Phenotype: White/Yellow
Dominant Genes
Recessive Genes
Genotype: AA or Aa Genotype: aa
Phenotype:
Brown/Black
Phenotype:
White/Yellow

22. shows alleles combine 8) Punnett Squares:
A Punnett square ________ how the parents’ ________ might ___________ in offspring.
shows
alleles
combine

23. top one parent’s alleles side second alleles
The ____ of the square shows _____ __________ ________ for the trait.
The ______ of the square shows the _________ parent’s ________ for the trait.
top
one
parent’s
alleles
side
second
alleles

24. box alleles combine offspring
Each _____ shows one way the ________ might ___________ in potential ___________.
box
alleles
combine
offspring

25. T T T t t t T T T t t t Let’s try some Punnett squares! Ex.1:
A heterozygous tall plant (Tt)
is crossed with another heterozygous tall plant (Tt). T T T t t t
Next we fill in the Punnett square. T T T
tall
tall
What would the offspring look like? t t t
tall
short

26. T T T T T T T T T t t t Now it’s your turn! Ex.2:
A homozygous tall plant (TT)
is crossed with a heterozygous tall plant (Tt). T T T T T T
Now fill in the Punnett square. T T T
tall
tall
What would the offspring look like? t t t
tall
tall