2.12.25 Lesson

Punnett Squares

Completing this quizizz will earn you 10 extra points on your Genetics and Punnett Squares assignment for this week!

Match

In rabbits, gray fur is dominant (G) to white fur (g), and black eyes are dominant (B) to red eyes (b). What are the phenotypes of rabbits that have the following genotypes? What is the genotype for fur color and eye color for the bunny pictured?

• GG or Gg

• gg

• BB or Bb

• bb

Gray fur

White fur

Black eyes

Red eyes

gg and bb

• Gray fur

• White fur

• Black eyes

• Red eyes

• gg and bb

Match

Match the following terms to their definitions

• Dominant Trait

• Recessive Trait

• Homozygous

• Heterozygous

• Gene

A trait that will show if it is in genes

A trait that is "hidden" by a dominant

A genotype with two of the same alleles

A genotype with two different alleles

A portion of DNA that carries a trait

• A trait that will show if it is in genes

• A trait that is "hidden" by a dominant

• A genotype with two of the same alleles

• A genotype with two different alleles

• A portion of DNA that carries a trait

Labelling

Label the parts of the Punnett Square

Drag labels to their correct position on the image

Recessive Trait

Homozygous Recessive Parent

Heterozygous Parent

Dominant Trait

Homozygous Recessive Offspring (50%)

Heterozygous Offspring (50%)

Probability

Ratios vs. Percentages

A percentage is a number that shows how often out of 100 possible outcomes an event occurs. For example, if you flip a coin 100 times, because there are only 2 possibilities (heads or tails) there's a 50% probability that it will land on either heads or tails (50 times out of 100).

A ratio represents the numbers of a probability. For example, in flipping a coin, you can get heads 1 out of 2 times or tails 1 out of 2 times for a ratio of 1:1.

Probability in Punnett Squares

In a Punnett Square, each individual square represents a 25% chance or a 1 out of 4 chance that an offspring will have the genotype.

Probability in Punnett Squares

​Genotypic Ratio: Ratio of Genotypes of the offspring.

Phenotypic Ratio: Ratio of Phenotypes of the offspring.

For this example, our genotypic ratio would be:
1/4 Homozygous Dominant,
2/4 Heterozygous, and
1/4 Homozygous Recessive or 1:2:1

The phenotypic ratio is
3/4 Black Fur and
1/4 White Fur or 3:1

Dropdown

A ​

Select answer

green pea plant (Gg) is crossed with a ​

Select answer

recessive yellow pea plant (gg). The ​

Select answer

ratio is 1 Gg : 1 gg and the phenotypic ratio is 1 ​

Select answer

: 1 ​

Select answer

Multiple Choice

In a heterozygous genotype, the ___________ allele takes over in the phenotype.

• recessive
• dominant
• lower case letter
• both 

Multiple Choice

In a flowering plant species, red flower color (R) is dominant over white flower color (r). What is the genotype of any white-flowering plant resulting from this species?

• rr

• rR

• RR

• Rr

Multiple Choice

How many alleles (letters) does a child get from EACH parent for each trait?

• 1

• 2

• 3

• 4

Independent Practice Time

Directions

The next slide will take you to the "clickable links" tab. Complete the activities there and then come back to the quizizz and complete the exit ticket question!

If you have questions, ask the sub or email me!

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Multiple Choice

In corn, smooth kernels (K) are dominant to wrinkled kernels (k). A farmer crosses two corn plants that are heterozygous for kernel texture. What percentage of the offspring will have smooth kernels?

***Hint: Do a Punnett Square!***

• 0%

• 25%

• 75%

• 100%