Question

a. straight hair is dominant to curly.

• ___ straight
• ___ straight
• ___ curly

b. pointed heads are dominant to round heads.

• ___ pointed
• ___ pointed
• ___ round

table 1: mendels traits and symbols for pea plants

traits	dominant allele	symbol	recessive allele
seed color	yellow	y	green

Explanation:

Step1: Analyze Part a (Hair Trait)

For a dominant trait (straight hair) over a recessive trait (curly hair), we use the convention where the dominant allele is represented by a capital letter (e.g., \( S \)) and the recessive by a lowercase letter (e.g., \( s \)).

• Homozygous dominant straight hair: \( SS \)
• Heterozygous straight hair: \( Ss \)
• Homozygous recessive curly hair: \( ss \)

Step2: Analyze Part b (Head Shape Trait)

For pointed heads (dominant) over round heads (recessive), let the dominant allele be \( P \) and recessive be \( p \).

• Homozygous dominant pointed heads: \( PP \)
• Heterozygous pointed heads: \( Pp \)
• Homozygous recessive round heads: \( pp \)

Answer:

Part a (Straight vs Curly Hair)

• Straight (homozygous dominant): \( SS \)
• Straight (heterozygous): \( Ss \)
• Curly (homozygous recessive): \( ss \)

Part b (Pointed vs Round Heads)

• Pointed (homozygous dominant): \( PP \)
• Pointed (heterozygous): \( Pp \)
• Round (homozygous recessive): \( pp \)

(Note: The allele symbols can be chosen as per convention, here \( S \) for straight, \( s \) for curly; \( P \) for pointed, \( p \) for round are used. Other valid symbols following dominant - recessive allele notation can also be used.)