Question
The pedigree diagram shows how a recessive trait is inherited in a family. The red circle shows a person with the trait.
An image of 2 squares connected to 2 circles.
Which conclusion is supported by the pedigree diagram?
A.
One parent is homozygous for the trait.
B.
The child without the trait is homozygous.
C.
Both parents are heterozygous for the trait.
D.
The child with the trait is heterozygous.
An image of 2 squares connected to 2 circles.
Which conclusion is supported by the pedigree diagram?
A.
One parent is homozygous for the trait.
B.
The child without the trait is homozygous.
C.
Both parents are heterozygous for the trait.
D.
The child with the trait is heterozygous.
Answers
GPT-4o mini
To determine the correct conclusion supported by the pedigree diagram, let's analyze the possible statements based on the inheritance pattern of a recessive trait:
1. **A. One parent is homozygous for the trait.**
- This is possible if at least one parent has the recessive trait (indicated by a red circle). However, we cannot conclude that one parent is homozygous just from the diagram.
2. **B. The child without the trait is homozygous.**
- A child who does not express a recessive trait could either be homozygous dominant (no alleles for the trait) or heterozygous (one allele for the trait, one without). Therefore, we cannot conclude that this child is homozygous.
3. **C. Both parents are heterozygous for the trait.**
- If two heterozygous parents had a child with the recessive trait, this could be true. However, without seeing specific notations for the parents, we cannot definitively state this.
4. **D. The child with the trait is heterozygous.**
- A child with a recessive trait must have two recessive alleles (homozygous recessive), not one dominant and one recessive (heterozygous). Therefore, this cannot be correct.
Based on the general rules of inheritance regarding recessive traits, the most likely answer supported by a typical pedigree diagram with a recessive trait present is **C. Both parents are heterozygous for the trait**, given that they can produce an offspring with the recessive trait. However, the precise conclusion would depend on the specific relationships depicted in the diagram. If the specific details of the parents indicate otherwise, I would need to reassess.
1. **A. One parent is homozygous for the trait.**
- This is possible if at least one parent has the recessive trait (indicated by a red circle). However, we cannot conclude that one parent is homozygous just from the diagram.
2. **B. The child without the trait is homozygous.**
- A child who does not express a recessive trait could either be homozygous dominant (no alleles for the trait) or heterozygous (one allele for the trait, one without). Therefore, we cannot conclude that this child is homozygous.
3. **C. Both parents are heterozygous for the trait.**
- If two heterozygous parents had a child with the recessive trait, this could be true. However, without seeing specific notations for the parents, we cannot definitively state this.
4. **D. The child with the trait is heterozygous.**
- A child with a recessive trait must have two recessive alleles (homozygous recessive), not one dominant and one recessive (heterozygous). Therefore, this cannot be correct.
Based on the general rules of inheritance regarding recessive traits, the most likely answer supported by a typical pedigree diagram with a recessive trait present is **C. Both parents are heterozygous for the trait**, given that they can produce an offspring with the recessive trait. However, the precise conclusion would depend on the specific relationships depicted in the diagram. If the specific details of the parents indicate otherwise, I would need to reassess.