Question

assess it! part 1

1. which statement is true about the punnett square?

h - shaggy hair
h - no hair
h h
hh hh
h hh hh
a. all offspring will have no hair.
b. all offspring will have shaggy hair.
c. 50% of offspring will have no hair.
d. 50% of offspring will have shaggy hair.

1. which statement is not true about the punnett square?

r - roll tongue
r - can’t roll tongue
r r
r rr rr
r rr rr
a. both parents carry at least one recessive allele.
b. all offspring can roll their tongue.
c. 50% of offspring can roll their tongue.
d. 50% of offspring cannot roll their tongue.

1. which allele pair would be considered homozygous dominant?

a. aa
b. aa
c. aa
your answers:

1. answer here
2. answer here
3. answer here

Explanation:

Question 1

The Punnett square for hair has all offspring as \( Hh \) (since one parent is \( HH \) and the other is \( hh \), resulting in all \( Hh \) offspring). \( H \) is for shaggy hair (dominant), so all offspring will have shaggy hair. Option A is wrong (they have shaggy hair), C and D are wrong as the ratio isn't 50% for either no or shaggy hair in this case (it's 100% shaggy). So the correct statement is B.

The tongue - rolling Punnett square has parents \( Rr \) (one) and \( rr \) (the other, from the square: \( Rr \) and \( rr \) crossing gives \( Rr, Rr, rr, rr \)). So 50% (\( Rr \)) can roll (dominant \( R \)) and 50% (\( rr \)) can't. Option A: One parent is \( Rr \) (has one recessive \( r \)) and the other is \( rr \) (has two recessive \( r \)), so both carry at least one recessive allele (correct). Option B: \( Rr \) can roll, \( rr \) can't, so not all can roll (wrong). Option C: 50% (\( Rr \)) can roll (correct). Option D: 50% (\( rr \)) can't roll (correct). So the statement that is not true is B.

Homozygous dominant means having two dominant alleles. For a dominant allele (let's say \( A \) is dominant), homozygous dominant is \( AA \). \( Aa \) is heterozygous (one dominant, one recessive), and \( aa \) is homozygous recessive. So the allele pair that is homozygous dominant is \( AA \).

Answer:

B. All offspring will have shaggy hair.

Question 2