Genetics Mini Quiz: Cobley

1. The punnett square shown below is set up correctly.

True

False

The punnett square shown below is not set up correctly.

Explanation

The punnett square shown below is not set up correctly.

2. The phenotype of a gene is the physical trait that shows and the genotype is the gene code for that trait.

True

False

The explanation for the given correct answer is that the phenotype refers to the observable physical traits or characteristics of an organism, while the genotype is the genetic code or combination of alleles that determine those traits. In other words, the phenotype is what we can see or measure, such as hair color or height, while the genotype is the underlying genetic information that determines the phenotype. Therefore, it is true that the phenotype of a gene is the physical trait that shows, and the genotype is the gene code for that trait.

Explanation

The explanation for the given correct answer is that the phenotype refers to the observable physical traits or characteristics of an organism, while the genotype is the genetic code or combination of alleles that determine those traits. In other words, the phenotype is what we can see or measure, such as hair color or height, while the genotype is the underlying genetic information that determines the phenotype. Therefore, it is true that the phenotype of a gene is the physical trait that shows, and the genotype is the gene code for that trait.

3. HH is heterozygous?

True

False

not-available-via-ai

Explanation

not-available-via-ai

4. Determine the phenotype for each genotype using the information provided about Squidward.

A long nose is dominant to a short nose. What type of noses are represented by the genotypes below?
a. NN = _________b. Nn = _________c. nn = _________

A. longb. shortc. short

A. shortb. shortc. long

A. longb. longc. short

A. shortb. shortc. long

The genotype NN represents a long nose because it is homozygous dominant, meaning it has two copies of the dominant allele. The genotype Nn represents a long nose as well because it is heterozygous, meaning it has one copy of the dominant allele. The genotype nn represents a short nose because it is homozygous recessive, meaning it has two copies of the recessive allele.

Explanation

The genotype NN represents a long nose because it is homozygous dominant, meaning it has two copies of the dominant allele. The genotype Nn represents a long nose as well because it is heterozygous, meaning it has one copy of the dominant allele. The genotype nn represents a short nose because it is homozygous recessive, meaning it has two copies of the recessive allele.

5. Match the following

Genetics

Homozygous

The "Father of Genetics"

Dominant

Recessive

Gene

Heterozygous

Submit

6.

Punnett squares are used by geneticists to determine the probability of different offspring genotypes. In the one shown below, what letter(s) belong in the lower right box?

S

AA

Aa

In a Punnett square, the different combinations of alleles from the parents are shown to determine the probability of different genotypes in the offspring. In this case, the Punnett square shows the cross between two individuals with genotype AA and aa. The lower right box represents the possible genotype of the offspring. Since the lowercase letter "a" represents the recessive allele, and both parents have the genotype aa, it is certain that the offspring will also have the genotype aa.

Explanation

In a Punnett square, the different combinations of alleles from the parents are shown to determine the probability of different genotypes in the offspring. In this case, the Punnett square shows the cross between two individuals with genotype AA and aa. The lower right box represents the possible genotype of the offspring. Since the lowercase letter "a" represents the recessive allele, and both parents have the genotype aa, it is certain that the offspring will also have the genotype aa.

7. You are studying flowers - the purple flowers are dominant (P) and the white flowers are recessive (p). Make a punnett square to cross a PP father and a PP mother and then answer the question below.

What are the colors of the parents and the offspring?

Parents are both purple and the offspring are a mix of white and purple.

Parents are both purple and the offspring are all purple.

The parents are a mix of purple and white and the offspring are all purple.

The parents are all white and the offspring are all white.

The given answer correctly states that the parents are both purple (PP) and the offspring are all purple. This is because in the punnett square, when both parents have the dominant purple allele (P), there is no possibility for the recessive white allele (p) to be passed on to the offspring. Therefore, all the offspring will inherit the dominant purple allele from both parents, resulting in them being all purple.

Explanation

The given answer correctly states that the parents are both purple (PP) and the offspring are all purple. This is because in the punnett square, when both parents have the dominant purple allele (P), there is no possibility for the recessive white allele (p) to be passed on to the offspring. Therefore, all the offspring will inherit the dominant purple allele from both parents, resulting in them being all purple.

8. Black fur(B) in guinea pigs is dominant over white fur(b). Create a punnett square that crosses two Heterozygous Guinea Pigs. What percentage of offspring will be white?

25%

100%

50%

75%

When crossing two heterozygous guinea pigs (Bb x Bb), there is a 25% chance of producing offspring with white fur. This is because the lowercase "b" represents the recessive allele for white fur, and in order for an offspring to have white fur, it must inherit the "b" allele from both parents. Since both parents are heterozygous (Bb), there is a 25% chance of each offspring inheriting the "b" allele from both parents and therefore having white fur.

Explanation

When crossing two heterozygous guinea pigs (Bb x Bb), there is a 25% chance of producing offspring with white fur. This is because the lowercase "b" represents the recessive allele for white fur, and in order for an offspring to have white fur, it must inherit the "b" allele from both parents. Since both parents are heterozygous (Bb), there is a 25% chance of each offspring inheriting the "b" allele from both parents and therefore having white fur.

9. When looking at cows, spotted fur is dominant (F) and black fur is recessive (f). A farmer crosses a heterozygous spotted cow with black cow. What is the genotype for each cow?

Spotted Cow = FFBlack Cow = ff

Spotted Cow = ffBlack Cow = Ff

Spotted Cow = FfBlack cow = ff

Spotted Cow = FfBlack cow = FF

The correct answer is that the genotype for the spotted cow is Ff and the genotype for the black cow is ff. This is because spotted fur is dominant (F) and black fur is recessive (f). The spotted cow is heterozygous, meaning it has one dominant allele (F) and one recessive allele (f). The black cow is homozygous recessive, meaning it has two recessive alleles (ff).

Explanation

The correct answer is that the genotype for the spotted cow is Ff and the genotype for the black cow is ff. This is because spotted fur is dominant (F) and black fur is recessive (f). The spotted cow is heterozygous, meaning it has one dominant allele (F) and one recessive allele (f). The black cow is homozygous recessive, meaning it has two recessive alleles (ff).

10. Some people have dimples. For this example, dimples are dominant (D) and no dimples is recessive (d). What is the genotype of the missing parent AND how many offspring have dimples?

Genotype of parent = DD4 offspring have dimples

Genotype of missing parent = Dd2 offspring have dimples

Genotype of missing parent = dd0 offspring have dimples

Genotype of missing parent = Dd3 of the offspring have dimples

The given information states that dimples are dominant (D) and no dimples are recessive (d). The genotype of the known parent is DD. Since the offspring have dimples, it means that they inherited the dominant allele from the known parent. Therefore, the missing parent must have at least one dominant allele (D) in order for the offspring to have dimples. The genotype of the missing parent is therefore Dd. The answer also states that 3 of the offspring have dimples, which supports the conclusion that the missing parent has the genotype Dd.

Explanation

The given information states that dimples are dominant (D) and no dimples are recessive (d). The genotype of the known parent is DD. Since the offspring have dimples, it means that they inherited the dominant allele from the known parent. Therefore, the missing parent must have at least one dominant allele (D) in order for the offspring to have dimples. The genotype of the missing parent is therefore Dd. The answer also states that 3 of the offspring have dimples, which supports the conclusion that the missing parent has the genotype Dd.