Mendelian Genetics Review

____________________ is the “Father of Genetics”. Gregor Mendel

_______________ is the passing of traits from parent to offspring. Heredity

A _________ represents the physical characteristics. Phenotype

How many chromosomes would a human have in their skin cells? 46

___________ are two forms of a gene (dominant & recessive) Alleles

How would you write a homozygous dominant genotype (use the 2nd letter of the alphabet ) BB

A homozygous genotype can also be called _____________ Pure

Which law states: when different alleles for a characteristic are inherited (heterozygous), the trait of only one (the dominant one) will be expressed? Law of Dominance

What sex chromosomes are present for a male? XY

What does the P generation represent? Parent’s genotypes

A cross between two hybrids will ALWAYS create what phenotypic ratio A cross between two hybrids will ALWAYS create what phenotypic ratio? Be specific!!!! 3 dominant : 1 recessive

What organism did Mendel use to conduct his research? Pea Plants

What is the F1 generation? The offspring from crossing the P generation

____________ is the study of heredity Genetics

Law of Independent Assortment Which law states the following: each factor (gene) is distributed (assorted) randomly and independently of one another in the formation of gametes (egg or sperm)? Law of Independent Assortment

A ___________ represents the types of genes that are inherited. Genotype

How many chromosomes did you inherit from your mom? 23

How would you write a homozygous recessive genotype (use the 2nd letter of the alphabet ) bb

A heterozygous genotype can also be called a _____________ Hybrid

How would you write a heterozygous genotype (use the 2nd letter of the alphabet ) Bb

Which Law states: each genetic trait is produced by a pair of alleles which separate during reproduction? Law of Segregation

List the gametes that can be produced from the following genotype: AaBb AB Ab aB ab

A ______ gene is the gene that shows up most often in a cross; represented by an uppercase letter Dominant

In guinea pigs, rough coats (R) are dominant to smooth coats In guinea pigs, rough coats (R) are dominant to smooth coats. Write the genotype for a homozygous rough coated guinea pig. RR

In guinea pigs, rough coats (R) are dominant to smooth coats In guinea pigs, rough coats (R) are dominant to smooth coats. What are the f1 genotypes from a cross with a smooth coated guinea pig and a homozygous rough coated. Genotype = 100% Rr

Are fraternal twins or identical twins more closely related?

In guinea pigs, rough coats (R) are dominant to smooth coats In guinea pigs, rough coats (R) are dominant to smooth coats. Write the genotype for a smooth coated guinea pig. rr

A ________ is a cross that only involves a single trait Monohybrid cross

List the gametes that can be produced from the following genotype: aaBB aB

What are two factors that affect who you are? Genes Environment

What sex chromosomes are present for a female? XX

How could a guinea pig breeder determine if a black guinea pig is homozygous dominant or heterozygous? Test cross- cross the guinea pig with a homozygous recessive guinea pig

________ is a tool used to solve genetic problems based on probability Punnett Square

Phenotype = 100% Rough coated In guinea pigs, rough coats (R) are dominant to smooth coats. What are the f1 phenotypes from a cross with a smooth coated guinea pig and a homozygous rough coated. Phenotype = 100% Rough coated

A ________ is a cross that involves two traits Dihybrid cross

A ______ gene is the gene that shows up less often in a cross; represented by a lowercase letter Recessive

In guinea pigs, rough coats (R) are dominant to smooth coats In guinea pigs, rough coats (R) are dominant to smooth coats. Write the genotype for a heterozygous rough coated guinea pig. Rr

The ________________________ is based on the genotype. phenotype

Which parent determines the sex of the child? Why? Father Only one that can give a Y chromosome

T or F: The tendency to produce twins runs in a family. True

How do identical twins form? a zygote from the same egg and same sperm cell spits into two

In corn, smooth seed texture (T) is dominant to wrinkled seed texture In corn, smooth seed texture (T) is dominant to wrinkled seed texture. Complete a test cross of a hybrid smooth seed texture corn. Determine the genotypes & phenotypes of the offspring. NOTE: Test cross= always cross w/ the homozygous recessive genotype! G: 50% Tt: 50% tt P: 50% Smooth: 50% wrinkled T t t Tt tt Tt tt

G: 100% Bb P: 100% Brown eyes b B B Bb Bb Bb Bb brown eyes (b) are dominant to blue eyes. What would be the genotypes and phenotypes of a cross between a homozygous brown eyed individual and someone with blue eyes. G: 100% Bb P: 100% Brown eyes B B b Bb Bb Bb Bb

2. In guinea pigs rough coated (R) is dominant over smooth coated (r) and black color (B) is dominant over white color (b). A rough coated and black guinea pig, whose mother was smooth and white is mated with a smooth, white animal. What are the parent genotypes? What are the genotypes and phenotypes of the offspring? (see Punnett square on next slide for answer) RrBb x rrbb P Cross =

RrBb Rrbb rrBb rrbb rb RB Rb rB rb 25% RrBb 25% Rrbb 25% rrBb 25% rrbb F1 Genotypes: 25% RrBb 25% Rrbb 25% rrBb 25% rrbb RrBb Rrbb rrBb rrbb F1 Phenotypes: 25% Rough/Black 25% Rough/White 25% Smooth/Black 25%Smooth/White

3. In squash the color white (W) is dominant over yellow and disk shape (D) is dominant over sphere shape. a) When crossing two homozygous squashes, one white, sphere and the other yellow, disk. Determine the parent genotypes. Then determine the genotypes and phenotypes of the F1 generation (see punnett square answers on next slide. WWdd x wwDD P Cross =

WwDd wD Wd Wd Wd Wd F1 Genotype: 100% WwDd F1 Phenotype: 100% White/Disk