Question

• allele- discrete version of the same gene• genotype- the genes of an organism for one specific trait• phenotype- the physical appearance of a trait in an organism• dominant trait refers to a genetic feature that \hides\ the recessive trait in the phenotype of an individual.• recessive describes a trait that is covered over (or dominated) by another form of that trait and seems to disappear.• homozygous- two alleles that are the same for a trait (pure)• heterozygous- two different alleles for a trait (hybrid)punnett square worksheetcomplete the following monohybrid crosses: draw a punnett square and list the possible genotypes and phenotypes of the offspring. be sure to remember that the capital letter is dominant.examplea green pea plant (gg) is being crossed with a green pea plant (gg). yellow is recessivegenotypes = 2 gg and 2 ggphenotypes = 4 green 0 yellow1) a green pea plant (gg) is crossed with a yellow pea plant (gg).genotypes =phenotypes =2) a tall plant (tt) is crossed with a tall plant (tt).genotypes =phenotypes =

Explanation:

Step1: Set up Punnett Square for Q1

Parent 1 (Gg) contributes alleles: $G$, $g$
Parent 2 (gg) contributes alleles: $g$, $g$

$$\begin{array}{c|cc} & G & g \\ \hline g & Gg & gg \\ g & Gg & gg \\ \end{array}$$

Step2: Identify Genotypes for Q1

Count unique genotype combinations: 2 $Gg$, 2 $gg$

Step3: Identify Phenotypes for Q1

$G$ (green) is dominant, $g$ (yellow) is recessive:

• $Gg$ = green, $gg$ = yellow → 2 green, 2 yellow

Step4: Set up Punnett Square for Q2

Parent 1 (TT) contributes alleles: $T$, $T$
Parent 2 (Tt) contributes alleles: $T$, $t$

$$\begin{array}{c|cc} & T & T \\ \hline T & TT & TT \\ t & Tt & Tt \\ \end{array}$$

Step5: Identify Genotypes for Q2

Count unique genotype combinations: 2 $TT$, 2 $Tt$

Step6: Identify Phenotypes for Q2

$T$ (tall) is dominant, so all offspring with $T$ allele are tall: 4 tall, 0 short

Answer:

1) Cross: Gg × gg

Punnett Square:

$$\begin{array}{c|cc} & G & g \\ \hline g & Gg & gg \\ g & Gg & gg \\ \end{array}$$

Genotypes = 2 Gg and 2 gg
Phenotypes = 2 green, 2 yellow

2) Cross: TT × Tt

Punnett Square:

$$\begin{array}{c|cc} & T & T \\ \hline T & TT & TT \\ t & Tt & Tt \\ \end{array}$$

Genotypes = 2 TT and 2 Tt
Phenotypes = 4 tall, 0 short