Punnett Squares
B = Brown eyes b = blue eyes Create a Punnett Square Female is heterozygous, Male has blue eyes
What percent of the children have blue eyes?
What percent of the children have brown eyes what is their genotype heterozygous or homozygous?
For Punnett Square see the whiteboard. 50% of the children have blue eyes. 50% of the children have brown eyes and their genotype is Bb heterozygous.
Define genotype and give a simple example using letters.
A genotype is and organism's genetic makeup. VV, Bb, MM, Mm are all examples of genotypes.
BB is the genotype. What is the alternate name of this genotype? What do we say instead of BB? B is dominant and the trait is pointy nose.
This genotype is homozygous dominant.
What does the word homozygous in genetics/heredity actually mean?
That there are two of the same alleles for a trait found on the gene.
Alleles are different combinations of a gene and we receive one copy of each gene (an allele) from each of our biological parents
V = Green teeth v = yellow teeth Create a Punnett Square Father is homozygous dominant. Mother is homozygous recessive.
What are the children's phenotype(s)?
Is their genotype dominant or recessive, heterozygous or homozygous?
For the correct Punnett Square see the whiteboard.
All of the children have green teeth.
All of their genotypes are heterozygous (Vv).
Define phenotype and give an example.
A phenotype is what is seen in an organism. Blue eyes can be a phenotype.
BB is the genotype. What trait is seen in the organism?
B is dominant and the trait is pointy nose.
b is recessive and the trait is rounded flat nose.
The dominant trait is seen and that trait is pointy nose.
What does the word heterozygous in genetics / heredity actually mean?
There are two different alleles for the trait found on the gene.
What is the definition of adaptive trait?
Adaptive trait is a trait that allows organisms to survive in their environment.
B = Brown eyes b = blue eyes Create a Punnett Square Father is heterozygous and mother is homozygous recessive.
What percent of the children are heterozygous and what is the phenotype?
What percent of the children are homozygous recessive and what is the phenotype?
50% are heterozygous (dominant) phenotype = brown eyes (Bb). 50% are homozygous recessive phenotype = blue eyes
True or False Every phenotype has a genotype.
True - Phenotypes are impossible without a genotype.
rr is the genotype. What do we call this genotype rather than saying rr?
r = recessive for long legs
R = dominant for short legs
This genotype is homozygous recessive.
When you have a heterozygous individual what trait is seen? The dominant one or the recessive one?
The dominant trait is the phenotype for the heterozygous individual.
When an organism has a homozygous genotype what is the phenotype? Is it dominant or recessive?
The phenotype can be dominant or recessive.
What is the purpose of a Punnett Square?
To determine the possible genotypes of the offspring.
Blue hair, green teeth, knobby knees, big feet, flat fingers are all examples of this? Hint: The answer is not characteristics or traits.
Phenotypes.
rr is the genotype. What is the phenotype for this genotype?
r = recessive for dimples
R = dominant for no dimples.
The phenotype is dimples and dimples are recessive.
In single-gene expressions write the dominant genotype(s) when you don't know the specific genotype. Use the letters B and/or b in your example.
There are two dominant genotypes when you don't know the dominant individual's genotype. These genotypes are BB and Bb. Homozygous dominant and heterozygous (dominant).
In an organism what really evolves as a response to changes in the organism's habitat?
The cells in the organism evolve as a result of changes in the organism's environment.
B = Brown eyes b = blue eyes Create a Punnett Square Mother is heterozygous (dominant) Father has dominant brown eyes. Hint: Be careful!!
There is not enough information to create a Punnett Square because we do not know if the father has a genotype that is homozygous dominant or heterozygous. The problem needs to identify whether the father is homozygous for brown eyes or heterozygous for brown eyes.
B = big feet, b = small feet Give the genotypes, whether they are dominant or recessive and phenotypes for each of the possible genetic combinations.
The genotypes are BB homozygous dominant. Bb heterozygous (dominant), bb homozygous recessive. The phenotypes are BB - big feet. Bb - big feet. bb - small feet.
Hh = the genotype. What do we call this genotype and what is the phenotype for this organism?
H = big hands
h = little hands
The genotype is known as heterozygous and the phenotype is big hands.
What does homozygous mean? What does heterozygous mean? Mention how the phenotypes are affected by the genotypes.
Homozygous means there are two of the same alleles on a gene (genotype) and the phenotype can either be dominant or recessive. Heterozygous means there are two different alleles (genotype) on a gene and the phenotype is dominant.
What is the process of Natural Selection?
The best suited traits are passed on through the process of Natural Selection.