Problem Explanation and Solution
The task involves using Punnett squares to predict the possible genotypes of offspring from given parents. Let's solve each part step by step.
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Example 1: Eye Color
-
Parents' Genotypes:
- Father: \( BB \) (dominant brown eyes)
- Mother: \( bb \) (recessive blue eyes)
-
Punnett Square Setup:
- The father contributes either \( B \) or \( B \).
- The mother contributes either \( b \) or \( b \).
\[
\begin{array}{c|cc}
& B & B \\
\hline
b & Bb & Bb \\
b & Bb & Bb \\
\end{array}
\]
-
Offspring Genotypes:
All offspring will have the genotype \( Bb \).
-
Phenotype:
Since \( B \) is dominant over \( b \), all offspring will have brown eyes.
Answer: The possible eye color of the child is
brown.
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Example 2: Hair Feature
-
Parents' Genotypes:
- Father: \( Cc \) (curly hair, dominant)
- Mother: \( cc \) (straight hair, recessive)
-
Punnett Square Setup:
- The father contributes either \( C \) or \( c \).
- The mother contributes either \( c \) or \( c \).
\[
\begin{array}{c|cc}
& C & c \\
\hline
c & Cc & cc \\
c & Cc & cc \\
\end{array}
\]
-
Offspring Genotypes:
- Possible genotypes are \( Cc \) and \( cc \).
-
Phenotype:
- \( Cc \): Curly hair (dominant)
- \( cc \): Straight hair (recessive)
Answer: The possible hair features of the child are
curly or
straight.
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Example 3: Petal Color in Flowers
-
Parents' Genotypes:
- First flower: \( RR \) (red petal, dominant)
- Second flower: \( Rr \) (yellow petal, recessive)
-
Punnett Square Setup:
- The first flower contributes either \( R \) or \( R \).
- The second flower contributes either \( R \) or \( r \).
\[
\begin{array}{c|cc}
& R & R \\
\hline
R & RR & RR \\
r & Rr & Rr \\
\end{array}
\]
-
Offspring Genotypes:
- Possible genotypes are \( RR \) and \( Rr \).
-
Phenotype:
- \( RR \): Red petal (dominant)
- \( Rr \): Red petal (dominant, since \( R \) is dominant over \( r \))
Answer: The new plant offspring will have
red petals.
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Example 4: Seed Pod Texture in Plants
-
Parents' Genotypes:
- First plant: \( SS \) (smooth seed pod, dominant)
- Second plant: \( ss \) (wrinkled seed pod, recessive)
-
Punnett Square Setup:
- The first plant contributes either \( S \) or \( S \).
- The second plant contributes either \( s \) or \( s \).
\[
\begin{array}{c|cc}
& S & S \\
\hline
s & Ss & Ss \\
s & Ss & Ss \\
\end{array}
\]
-
Offspring Genotypes:
All offspring will have the genotype \( Ss \).
-
Phenotype:
Since \( S \) is dominant over \( s \), all offspring will have smooth seed pods.
Answer: The new plant offspring will have
smooth seed pods.
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Final Answers:
1.
Eye Color: \(\boxed{\text{Brown}}\)
2.
Hair Feature: \(\boxed{\text{Curly or Straight}}\)
3.
Petal Color: \(\boxed{\text{Red}}\)
4.
Seed Pod Texture: \(\boxed{\text{Smooth}}\)
Parent Tip: Review the logic above to help your child master the concept of punnett square practice problems worksheet.
