2. Gregor Mendel inheritance of traits
1. Who is named the “Father of Genetics?”
Gregor Mendel
2. Why did he use pea plants?
To study the
inheritance of traits

3. AA or aa What do pure bred, true breeding, and homozygous mean?
All mean the same thing…
Both alleles are either
capitals or lower case.
AA or aa

4. What do hybrid and heterozygous mean? Actually mean the same thing…
A a
2 Alleles are different
A a
A a

5. All HYBRID (Gg) offspring result
What type of offspring results when you cross two pure “true” breeding parents with different traits?
All HYBRID (Gg) offspring result

6. Understand which is the P, F1, F2 generations and how you get each.

7. What results when the offspring Tt (F1) of true breeding parents self-pollinate (breed with themselves)?
Tt x Tt T t TT Tt tt
Genotype Ratio:
1 RR: 2 Rr: 1 rr
Phenotype Ratio:
3 Round: 1 Wrinkled

8. Probability= The chance of something happening!
getting heads
½ or 50%

9. More times you flip a penny, the more likely you are to get the “expected” outcome (probability).
½ heads, ½ tails

10. If you toss a coin 6 times in a row, what is the probability it will land heads for all 6 tosses?
½ x ½ x ½ x ½ x ½ x ½
1/64

11. “Law of Independent Assortment”
During gamete formation, genes for different traits separate without influencing the other.
“Law of Independent Assortment”
Foil each parent
to get 4 gametes
G g Y y GY Gy gY gy

12. Complete Dominance Incomplete Dominance Co-Dominance
The dominant trait (G) masks (hides) the recessive trait (g) and only the dominant trait shows up in the phenotype.
Incomplete Dominance
Neither trait is dominant over the other and a new trait is displayed. BLENDING!!!
Red flowers crossed with white flowers make pink flowers.
Co-Dominance
Both traits are equally displayed and neither is dominant over the other.
ABO blood types: A blood x B blood =
AB blood

13. What are polygenic traits?
Traits that have a wide variety of color ranges such as eye colors, hair color, skin color and height.

14. Genotype IAIA or IAi IBIB or Ibi IAIB ii
Phenotype A Blood B Blood AB Blood O Blood

15. Co-Dominance Describe the genotypes and phenotypes of each blood type:
AB Blood has same
Genotype & Phenotype

16. How many different gametes?
First determine how many different letters are there for each letter type then multiply!
A A B b C c D d E E F F G g H h
1 x 2 x 2 x 2 x 1 x 1 x 2 x 2 =
32 gametes

17. Can this parent AaBBccDdeeFfGgHH
have a child with the following genotype? Why or why not?
NO, because the parent would need to have a big E in their genotype in order for the child to have both big E’s.
A A B b C c D d E E F F G g H h

18. Homologous Chromosome Pair
What is this picture called? Karyotype
Homologous Chromosome Pair
AUTOSOMES
Sex Chromosomes

19. Karyotype: Picture of all paired chromosomes
Shows:
Autosomes = all chromosomes # chromosome pairs (not sex chromosomes)
Sex Chromosomes
XX= female or XY= male (# 23 pair)
Homologous Chromosomes = chromosomes that code for the same traits and pair up with each other
Inherited Disorders (ex: Down’s, Turner’s, Kleinfelter’s, Super males/Super females)

20. What are the chromosome pairs for a …
FEMALE MALE
XX XY

21. Non-disjunction –When chromosome pairs don’t separate properly during Meiosis I
Can involve all chromosomes (sex, autosomes, homologous)

22. Down’s Syndrome (Trisomy 21)

23. Kleinfelter’s Syndrome
XXY

24. Turner’s Syndrome XO

25. Super Female

26. Super Male XYY

27. determines sex of offspring
Father
determines sex of offspring
Father provides either an X or a Y to pair up with the mother’s X to make a boy or girl
50% chance of Boy XY % chance of Girl XX

29. Carrier Female x Male Colorblind Sex-linked traits only carried on X
Know the term Sex-linked genes/traits and how the key and Punnett square would look. What chromosome carries these types of traits?
Sex-linked gene/trait – Traits linked to sex chromosomes such as hemophilia or colorblindness
XBXb x XbY
Carrier Female x Male Colorblind XB Xb
XBXb
XbXb Y
XBY
XbY
Phenotypes:
1 Female/Carrier
1 Female/Colorblind
1 Male/Normal
1 Male/Colorblind
Sex-linked traits only carried on X
Y doesn’t carry traits!

31. Pedigree Chart 4 Generations shown
Normal Male
Normal Female
Female with Trait
Carrier Female
Male with Trait
Line = Marriage
Pedigree Chart
Shows how a trait is passed from one generation to the next
Shows male or female
Shows “no trait” “carries trait” or “has trait”
4 Generations shown

32. REMEMBER: IN SEX-LINKED PEDIGREES, MALES CANNOT BE CARRIERS OF THE TRAIT. THEY EITHER HAVE IT OR NOT.

33. Dominant- Trait is one that can mask (hide) the recessive trait
Recessive- Trait that gets masked (hidden) by the dominant trait
Punnett Square- Tool to determine possible outcomes (probability)
Homozygous- When both alleles look the same (AA or aa)
Heterozygous – When both alleles do not look the same (Aa)
Phenotype – The “physical” appearance (tall, short)
Genotype – Allele letters (Aa, TT, tt)

34. Allele- Different forms of a gene
Gametes- Sex Cells (egg & sperm)
Gene- Part of a chromosome; codes for a trait
Genetics- Study of how traits are passed generation to generation
Karyotype- Picture of all paired chromosomes - looking for sex and the presence of abnormal # of chromosomes
Pedigree- Chart that shows passing of trait from one generation to the next generation
Probability - Chance of something happening
Punnett Square- Chart showing possible offspring from a parent cross.

35. Co-dominance – Both alleles expressed EQUALLY
Incomplete dominance – Blending of traits
Diploid – Having 2 sets of chromosomes
Haploid – Having 1 set of chromosomes
Independent Assortment – Genes that separate have no effect on the other’s inheritance
Non-disjunction – When chromosomes don’t separate
Segregation – Separation of alleles during gamete formation
Multiple Alleles – 2 or more alleles code for a trait
Polygenic Traits – Many genes working together to give a trait such as eye color or height

36. Incomplete Dominance Cross
Know how to do the following types of crosses:
Monohybrid Cross
Dihybrid Cross
Incomplete Dominance Cross
Sex-linked Cross
Must show: key, parents’ genotypes, possible gametes, Punnett square, genotypes and phenotypes of offspring