Question

In humans, a cleft chin is dominant and no-cleft is recessive. What will the generations look like? Assume that Mendel’s method of crossing two true breeding parents with opposite traits is followed. Choose two correct answers.
Responses

The
generation,
generation, and
generation will have all cleft chins.
The cap p generation, cap f sub 1 generation, and cap f sub 2 generation will have all cleft chins. - this question requires at least 2 answers

The
generation and
generation will have all no-cleft chins.
The cap p generation and cap f sub 2 generation will have all no-cleft chins. - this question requires at least 2 answers

The
generation,
generation, and
generation will have all no-cleft chins.
The cap p generation, cap f sub 1 generation, and cap f sub 2 generation will have all no-cleft chins. - this question requires at least 2 answers

The
generation,
generation, and
generation will have cleft chins and no-cleft chins.
The cap p generation, cap f sub 1 generation, and cap f sub 2 generation will have cleft chins and no-cleft chins. - this question requires at least 2 answers

The
generation and
generation will have all cleft chins.
The cap p generation and cap f sub 1 generation will have all cleft chins. - this question requires at least 2 answers

The
generation will have all cleft chins.
The cap f sub 1 generation will have all cleft chins. - this question requires at least 2 answers

The
generation and
generation will have cleft chins and no-cleft chins.
The cap p generation and cap f sub 2 generation will have cleft chins and no-cleft chins. - this question requires at least 2 answers
This question requires at least 2 answers.
This question requires at least 2 answers.

Answer 1

To analyze the inheritance of the cleft chin trait using Mendelian genetics, let's represent the alleles as follows:

- **C** = dominant allele for cleft chin
- **c** = recessive allele for no-cleft chin

When we follow Mendel's method of crossing two true-breeding parents with opposite traits, here's how the generations would break down:

1. **P Generation (Parental)**:
- One parent is homozygous dominant (CC) for cleft chin.
- The other parent is homozygous recessive (cc) for no-cleft chin.
- Outcome: All offspring in the F1 generation will have the genotype (Cc), which expresses the cleft chin trait since it is dominant.

2. **F1 Generation**:
- All offspring from the P generation (Cc) will show the cleft chin trait.
- If we cross two F1 individuals (Cc x Cc) to produce the F2 generation, we can use a Punnett square to predict the genotypes.
- Possible genotypes from this cross would be:
- CC (cleft chin),
- Cc (cleft chin),
- cc (no-cleft chin).
- The expected phenotypic ratio would be 3 cleft chins (CC and Cc) to 1 no-cleft chin (cc).

Based on this analysis, the correct answers from the choices provided would be:

1. **The P generation and F1 generation will have all cleft chins.**
(Both the P generation and the F1 generation will express cleft chins due to the presence of at least one dominant allele.)

2. **The F1 generation and F2 generation will have cleft chins and no-cleft chins.**
(The F2 generation will include both traits due to the segregation of the alleles from the heterozygous F1 parents.)

So, the two selected responses would be:

- The P generation and F1 generation will have all cleft chins.
- The F1 generation and F2 generation will have cleft chins and no-cleft chins.