Question

in a group of cows, some individuals have a black coat and others have a red coat. in this group, the gene for the coat color trait has two alleles. the allele for a black coat (l) is dominant over the allele for a red coat (l). this punnett square shows a cross between two cows. punnett square image: rows with l, l; columns with l, l; cells with ll, ll, ll, ll what is the expected ratio of homozygous dominant to heterozygous to homozygous recessive offspring genotypes? write the most likely ratio. blank boxes for ratio: □:□:□

Explanation:

Step1: Identify Genotypes

Homozygous dominant: \( LL \) (not present in Punnett square). Heterozygous: \( Ll \) (4 times). Homozygous recessive: \( ll \) (not present). Wait, re - check: The Punnett square has all \( Ll \)? Wait, no, the top alleles are \( l, l \) and left are \( L, L \). So offspring are all \( Ll \)? Wait, no, wait the Punnett square cells: all four are \( Ll \). Wait, homozygous dominant (\( LL \)): 0, heterozygous (\( Ll \)): 4, homozygous recessive (\( ll \)): 0. So ratio of homozygous dominant : heterozygous : homozygous recessive is \( 0:4:0 \), which simplifies to \( 0:1:0 \) (but since 4 cells, 0 (LL) : 4 (Ll) : 0 (ll), so 0:4:0 or 0:1:0 when simplified per 1 set? Wait, no, the Punnett square has 4 cells. Let's count:

Homozygous dominant (\( LL \)): To get \( LL \), we need \( L \) from both parents. But one parent gives \( l \) (top row) and the other \( L \) (left column). So no \( LL \) offspring.

Heterozygous (\( Ll \)): Each cell is \( Ll \), so 4 out of 4.

Homozygous recessive (\( ll \)): To get \( ll \), need \( l \) from both parents. But the left - hand parent only gives \( L \), so no \( ll \) offspring.

So the number of homozygous dominant (LL) is 0, heterozygous (Ll) is 4, homozygous recessive (ll) is 0. So the ratio is \( 0:4:0 \), which can be written as \( 0:1:0 \) (dividing each by 4) or \( 0:4:0 \).

Step2: Simplify the Ratio

Since we have 0 homozygous dominant, 4 heterozygous, and 0 homozygous recessive, the ratio of homozygous dominant : heterozygous : homozygous recessive is \( 0:4:0 \), which simplifies to \( 0:1:0 \) (but typically, we can present it as \( 0:4:0 \) or reduce by the greatest common divisor (which is 4 here) to \( 0:1:0 \)).

Answer:

\( 0:4:0 \) (or \( 0:1:0 \) when simplified)