https://www.khanacademy.org/science/biology/heredity-and-genetics
Introduction to heredity
Name: ______________
An allele is a specific ______________ of a gene.
Monohybrid crosses:
allele allele
Eye color: _____ _____
Tooth size:_____ _____
1st allele
2nd allele
both alleles
Genotype of offspring: ____(from mom)____(from dad) or ______
A heterozygote genotype has _____ versions of each gene.
Genotype
Phenotype
Bb
bB
BB
Bb
What is a hybrid and is it the same as heterozygous?
Complete the Punnett square for two hybrid brown eyed parents :
What are the phenotypes (fractions and percentages)?
Punnett Square Fun
A ___________ square is a grid used to _____________ allele (gene) combinations. This prediction
was named for British biologist, ____________________, a late 19th century biologist. Incidentally,
another member of the Punnett family designed a wide meshed basket for transporting fruit to the
market and called the basket a _____________ (one t).
Complete dominance
Mom: BB
Dad: Bb
What’s the probability of having a blue eyed child?
What’s the probability of having a homozygous dominant brown eyed
eyed child?
What’s the probability of having a heterozygous dominant brown eyed
eyed child?
Incomplete dominance
Red flowers
White flowers
Plant #1 - RW
Plant #2 - RW
What is the probability of having a PINK flowered plant?
Codominance
Blood type
Phenotype:
Genotype:
A
B
O
AB
Mon – AO
Dad - AB
What are the probability of having “A” blood type?
What are the probability of having “AB” blood type?
What are the probability of having “B” blood type?
How could a child of this couple have “O” blood type?
Eyes and teeth:
b=blue
B=Brown
t=small teeth
T=big teeth
How does this demonstrate independent assortment?
Because these genes are on different chromosomes there’s no ___________ if
between eyes color and teeth size. Complete drawing:
Linked traits
Hair color: these genes are on the same chromosomes so there’s a ___________
between the hair color genes. Complete drawing:
Dihybrid cross
Mom’s genotype: BbTt
Her four possible gametes (eggs) would be:
Dad’s genotype: BbTt
His four possible gametes (sperm) would be:
After completing the Punnett square:
Possible phenotypes
brown eyes, big teeth:
Brown eyes, little teeth:
Blue eyes, big teeth:
Blue eyes, small teeth:
Out of how many total possibilities?
Now complete the following
genotypic and phenotypic
Genetics 101 – Lesson 1
How many cells?
The nucleus contains how many genes? What about the mitochondria? What’s the total?
What and where are genes?
How long is all your DNA? How can it fit in the
nucleus?
What is the structure of DNA?
Label the drawing:
What do these bases spell out?
What do these genes code for?
How does your body produce different proteins
in different parts of the body?
What percent of your DNA do you share with other species? (give examples)
Genetics 101 – Lesson 2
What are SNPS?
What are the three most common SNPS?
What does the similarity or differences in DNA tell you about your neighbor?
Genetics 101 – Lesson 3
Where do your genes come from?
What are these pairs called?
What makes your siblings (if you have any) different from you?
What made each of your sperm (or egg) different from each other?
Draw a three panel (three drawings) explaining crossing over:
What’s the difference in nuclear DNA and mitochondrial DNA, and where does the mitochondrial
DNA come from?
Genetics 101 – Lesson 3
What are Phenotypes?