Punnett Squares, Dominance, and Inheritance MAKEUP

Dominance & Inheritance

Unit 4: Genetics

​Mendel's Work : Inheritance

• ​Mendel's work was important to understanding inheritance.

​

• ​In keeping accurate data, Mendel concluded heredity was related to the principles of probability.

​Mendel & Inheritance

• ​Observe the crosses between two green plants.

• ​We can predict that the offspring will have the following outcomes:

  • ​GG (25%) -- green color

  • ​Gg (50%) -- green color

  • ​gg (25%) -- yellow color

​Punnett Square

​Punnett Square = a chart used to predict the genotype & phenotype of a trait in the offspring of two mates

Inheritance : Dominance

​There are three (3) types of dominance:

​

​Complete Dominance: dominant trait masks the recessive

Inheritance : Dominance

​There are three (3) types of dominance:

​

Codominance: both alleles equally show dominance for a trait

Inheritance : Dominance

​There are three (3) types of dominance:

​

Incomplete Dominance: both alleles equally show dominance for a trait

Multiple Choice

What type of dominance is shown in the picture?

• Complete dominance

• Incomplete dominance

• Codominance

​Two Dominant alleles BLEND together and create an EVEN MIX of the two parents.

Incomplete Dominance

​BOTH of the alleles show up, often leaving stripes or spots.

Co-Dominance

Match

Match the following

Co-Dominanance Chicken

Incomplete Dominance Chicken

Incomplete Dominance Punnet Square

Codominance Punnet Square

• Co-Dominanance Chicken

• Incomplete Dominance Chicken

• Incomplete Dominance Punnet Square

• Codominance Punnet Square

Multiple Choice

A condition in which both alleles for a gene are expressed so that both traits are visible is known as ---

• Codominance

• Incomplete dominance

Multiple Choice

The blending of two traits is known as ---

• incomplete dominance

• codominance

Heterozygotes in this pattern will express both alleles to some degree. There is always one that is dominant, but sometimes it's 90/10 and sometimes its 60/40.​

Incomplete Dominance is interesting because it doesn't follow a TOTALLY predictable pattern. ​

What is incomplete dominance?

​

Some text here about the topic of discussion

While mylinated (darker) skin is dominant, it is incomplete domiance to non-mylinated (light) skin. This is why some familes can have kids of varrying skin tones, all from the same 2 parents. ​

​

Human skin tone is a great example of incomplete dominance​!

Multiple Choice

Which puppies in this litter are showing incomplete dominance in their fur color?

• White (yellow)

• Black

• Chocolate

Multiple Choice

Which horse coat color shows incomplete dominance?

• Creme

• Chesnut

• Palomino

Multiple Choice

These two goldendoodles are brothers, and they both are showing incomplete dominance in their coat texture. If curly hair is dominanct, which doodle is only 60/40 for coat texture?

• the one on the left

• the one on the right

In codominance, both alleles are expressed fully- like spots.

​

In incomplete dominance, both alleles are expressed, but mixed together, and one is expressed more than the other. ​

​How does incomplete dominance differ from codominance?

Multiple Choice

In one flower plant, some buds can be different shades of a color than their neighbor. On this plant, which flowers are showing a 90/10 incomplete dominance if the red is dominant?

• the lighter pink

• the darker pink flowers

• the white flowers

Incomplete= hybrid is a third phenotype that only shows part of the dominant trait

​

Incomplete vs. Codominant Traits

Codominant= 2 dominant alleles, both are seen in heterozygous/hybrid

Ex. stripes or spots

​

Incomplete vs. Codominant Traits

Multiple Choice

Red= dominant

White= recessive

What is the genotype of the pink flower?

• RR

• Rr

• rr

Multiple Choice

Incomplete dominance...

• where their is a partial dominant trait in the heterozygous

• always shows the dominant trait, as long as you have 1 capital letter

Multiple Choice

If....

R= red

W= white

What would be the genotype of the heterozygous?

• RR

• Red

• RW

• Red and White Stripes

• WW

For each of the next questions, look at the picture and say what type of trait is being shown.

Multiple Choice

What trait is being shown?

• Incomplete

• Codominance

Multiple Choice

What trait is being shown?

• Incomplete

• Codominance

Multiple Choice

What trait is being shown?

• Incomplete

• Codominance

Multiple Choice

What trait is being shown?

• Incomplete

• Codominance

Multiple Choice

What trait is being shown?

• Incomplete

• Codominance

Multiple Choice

A calico cat shows both the traits for orange fur and black fur. What kind of allele expression is this?

• incomplete dominance

• codominance

Match

Match the following

• Incomplete

  Dominance

• Codominance

• A blending

• strips and spots

Partial dominant trait

Get to see both dominant traits at the same time

Incomplete dominance

Codominance

• Partial dominant trait

• Get to see both dominant traits at the same time

• Incomplete dominance

• Codominance

Multiple Choice

The physical appearance of a trait is known as the-

• genotype

• phenotype

• Homozygous

• intelligence

Multiple Choice

Aa, DD, bB, yy are all examples of

• genotypes
• phenotypes

Multiple Select

Which of the following is/are an example(s) of a phenotype? Select all that apply.

• tall

• purple

• AA

• wrinkled

• bb

Multiple Choice

Different versions of a trait (tall or short, white or purple) are called

• alleles

• traits

• versions

• genes

Multiple Choice

If something is heterozygous, it is also _____

• purebred

• hybrid

• dominant

• recessive

Multiple Choice

Which of the following is homozygous recessive?

• rr
• AA
• TT
• Ff

Multiple Choice

G = green, g = yellow
The genotype for a yellow plant is...

• GG
• Gg
• gg
• all of the choices result in yellow

Multiple Choice

If A = red fur and a = white fur, what color fur would Aa be?

• red

• white

• purple

• blue

Match

Match the following vocabulary words with their definitions

• Genetics

• Heredity

• Trait

• Genotype

• Phenotype

The Scientific study of heredity

The process in which characteristics are passed down from parents to offspring.

An organism's characteristics.

The specific genetic make up or "code" for an individual.

The total physical appearance for an individual.

• The Scientific study of heredity

• The process in which characteristics are passed down from parents to offspring.

• An organism's characteristics.

• The specific genetic make up or "code" for an individual.

• The total physical appearance for an individual.

Multiple Choice

Which of the following genotypes is homozygous dominant?

• A

• Aa

• AA

• aa

Multiple Choice

A green pea plant (Gg) is crossed with a yellow pea plant (gg). Describe the genotype of the offspring.

• 50% heterozygous and 25% homozygous recessive

• 50% heterozygous and 50% homozygous recessive

• 100% homozygous recessive

• 25% heterozygous and 50% homozygous

Multiple Choice

What are the possible genotypes for this cross?

• TT = 25% Tt= 50% tt=25%

• all tall

• TT= 75% tt = 25%

• Tt = 100%

Multiple Choice

If brown eyes are dominant over blue eyes, what would be the parent genotypes if two heterozygous brown eyed persons were crossed?

• BB and bb

• BB and Bb

• Bb and Bb

• bb and Bb

Multiple Choice

In plants, tall (T) is dominant to short (t). Draw a punnett square and perform the following cross: Tt x Tt

What is the probability of producing a short plant?

• 0%

• 25%

• 50%

• 75%

Multiple Choice

What genotype would go in box 2? And is it Homozygous or Heterozygous?

• BB Heterozygous

• Bb Heterozygous

• bb Homozygous

• Bb Homozygous

Match

Having a Widow's Peak is dominant (W) over not having one (w). If parent A (WW) and parent B (ww) have a child, what is the likelihood that--

• The child will have a widow's peak

• The child will not have a widow's peak

• The genotype of these children

100%

0%

Ww

• 100%

• 0%

• Ww

Multiple Choice

Which of the following must be the father's genotype?

• RR

• Rr

• rr

Multiple Choice

In pea plants, the tall allele is dominant to the short allele. What key would demonstrate this?

• Tall = T
  Short = S
• Tall = T
  Short = t
• Tall = t
  Short = T
• Tall = TT
  Short = tt

Multiple Choice

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

• recessive
• dominant
• lower case letter
• both 

Multiple Choice

Dominant alleles are represented by a:

• Male gene
• lowercase letter
• recessive trait
• capital letter

Multiple Choice

Identify the homozygous dominant genotype:

• FF

• Ff

• ff

• fF

Multiple Choice

Which of the following would be a phenotype?

• Aa

• red hair

• heterozygous

• aa

Multiple Choice

Which of the following genotypes is heterozygous?

• Bb
• BB
• bb
• B

Multiple Choice

Which of the following genotypes is homozygous dominant?

• Yy

• yY

• yy

• YY

Multiple Choice

Which of the following genotypes is homozygous recessive?

• Tt

• tt

• TT

• tT

Multiple Choice

Which choice best represents the genotypic ratios for the offspring of this cross?

• 1 Yy: 2 yy: 0 YY

• 2 Yy: 2 yy: 0 YY

• 3 Yy: 1 yy: 0 YY

• 1 Yy: 3 yy: 0 YY

Multiple Choice

Fill in the Yellow Box

• AA

• Aa

• aa

• none of these

Multiple Choice

Fill in the Yellow Box

• Bb

• BB

• bb

• none of these

Multiple Choice

What is the probability that the offspring born from this cross will have a homozygous dominant genotype?

• 25%

• 50%

• 75%

• 100%

Explanation Slide...

GG = 50%

Multiple Choice

The punnett square is used to tell the color of a frogs skin. "G" means green skin and "g" means brown skin. What is the probability the baby frogs from this cross will have brown skin?

• 0%

• 25%

• 50%

• 100%

Explanation Slide...

gg would lead to brown skin. None of the offspring of this cross are gg (50% are GG ad 50% are Gg)

Multiple Choice

Purple (P) is dominant to the white (p).

According to the Punnett Square, what is the probability of an offspring being purple?

• 25%

• 0%

• 100%

• 50%

Explanation Slide...

100% of the offspring from this cross will be Pp which would be purple. (Only pp would be white.)

Multiple Choice

What is the yellow seed genotype?

• aa
• Aa
• AA
• AA or Aa

Multiple Choice

What is the dominant trait?

• yellow pea seeds

• green pea seeds

• there is no dominant seed

• Jolly green giant

Explanation Slide...

Since AA and Aa are yellow, we know that only one A is required to lead to a yellow seed. Therefore yellow is the dominant trait.

Multiple Choice

What are the genotypic probabilities for the offspring of this cross?

• 25% blue eye 75 % brown eye

• BB = 25% Bb = 50% bb = 25%

• BB= 50 % bb = 50%

• All brown eye

Multiple Choice

What are the parents' genotypes?

• Homozygous for brown eyes
• Heterozygous for brown eyes
• Homozygous for blue eyes
• Heterozygous for blue eyes

Multiple Choice

What is the phenotype for the recessive trait?

• brown eyes
• green eyes
• blue eyes

Multiple Choice

A section of the DNA strand that determines a specific trait

• gene
• trait
• chromosome
• allele