1. SC.912.L.16.1
Use Mendel’s laws of segregation and independent assortment to analyze patterns of inheritance.
Clarifications
Students will use Mendel’s laws of segregation and independent assortment to analyze patterns of inheritance.
Students will identify, analyze, and/or predict inheritance patterns caused by various modes of inheritance.
Content Limits
Items referring to general dominant and recessive traits may address but will not assess the P and generations. F1
Items addressing dihybrid crosses or patterns that include codominance, incomplete dominance, multiple alleles, sex-linkage, or polygenic inheritance may assess the P and generations. F1
Stimulus Attributes
Inheritance outcomes may be expressed in percent, ratios, or fractions.
Scenarios may refer to codominance or incomplete dominance but not both codominance and incomplete dominance.
Punnett squares may be used to predict outcomes of a cross.
Response Attribute
Options may include codominance or incomplete dominance but not both.
ESSENTIAL QUESTION: How do genes influence the variety of organisms that exist?

2. Mendelian Genetics

3. Gregor Mendel: Considered the “Father of Genetics”
Genetics – the study of heredity and the variation of inherited traits.
**Inheritance theory – states genetic material of offspring is a uniform blend of the parents’ genetic material.

5. Key Vocabulary for Understanding Genetics
Gene: small section of DNA passed from parents to offspring that codes for a particular specific trait.

6. Key Vocabulary for Genetics
Alleles- All the different forms of the same gene.
Types of Alleles:
Dominant allele - Prevents the expression of another allele when in a heterozygote, represented by capital letter.
Recessive allele - expression is masked/hidden in a heterozygote, represented by a lower case letter.

7. Key Vocabulary for Genetics
Genotype: combination of genes that are inherited from both parents.
Homozygous dominant
two dominant alleles- TT
Homozygous recessive
Two recessive alleles- tt
Heterozygous/Hybrid
One dominant and one recessive- Tt
Remind students that prefixes give clues to the meaning of the words. “Homo” means same. “Hetero” means different.

8. Phenotype: physical appearance caused by the genotypeTT Tt tt
Phenotype
Tall stems
Short stems

9. Law of Segregation: T t T t TT
The two alleles for a trait separate during meiosis when gametes (eggs and sperm) are formed.
A parent passes on only one allele for each trait to each offspring. tt t
Please clarify that this occurs for homologous chromosomes. Also, clarify that the gametes and offspring represent one of several possibilities. Tt t T
from Mom
from Dad
offspring
Dad
Mom

10. Law of Independent Assortment
Two or more genes on separate chromosomes are inherited independently of each other.
Example:
Seed color and flower color are inherited separately.
Limit discussion to the basics shown; do not introduce the concept of linkage in this FCIM lesson.

11. GENETICS AND PREDICTIONS
Scientists use probability to predict traits in offspring.
A Punnett Square organizes information to make genetic predictions.
Monohybrid Cross (one trait) & Complete Dominance

12. Completing a Punnett Square
Step 1: Determine each parents gametes and all possible gamete allele combinations.
Step 2: Complete the Punnett square
Step 3: Analyze genotypic and phenotypic ratios.

13. Complete Dominance Monohybrid
Inheritance of one trait from each parent.
T t
T t
Parents are both heterozygous tall pea plants.
P1 ______ X ______ T t
Offspring Genotype
1 T T : 2 T t : 1 t t T
T T
T t
Offspring Phenotype t
T t
t t
3 Tall : 1 Short

14. Scaffolding Skills Dominant Allele D e K L N o R S Recessive Allele
M n d F G I k P
Homozygous (Pure) Dominant Genotype
AA Gg KK ll pp Rr TT
Homozygous (Pure) Recessive Genotype
Ee Ff HH Oo qq Uu ww
Dominant Phenotype
AA Dd EE ff Jj RR Ss
Recessive Phenotype
Aa Gg Ff Oo PP ss tt
Heterozygous Dominant Genotype
RR Mm cc TT Hh ee Ff

15. Trait Genotype Phenotype Heterozygous stem length
Homozygous dominant seed shape
Heterozygous colored seed coat
Homozygous recessive stem length
Heterozygous for both pod color and shape.
Homozygous recessive flower position and Heterozygous for stem length
Homozygous dominant for both seed shape and color.
Homozygous dominant for seed shape and Homozygous recessive for pod color. Ll
Long Stem RR
Round Cc
Colored ll
Short stem
Green & Smooth
GgSs
aaLl
Terminal & Long
RRYY
Round & Yellow
RRGG
Round & Green