Question

punnett square practice
tall height in plants is dominant to short length. use this information to answer the given problems below. underline important information and write the alleles (letters) shown to represent genotypes if they arent given.
example problem: a tt (tall) plant is crossed with a tt (short plant).
probabilities

genotypes %	phenotypes %
0% tt	0% short
0% tt

punnett square

parents →	t	t
t	tt	tt

1. a heterozygous (tall) plant (tt) is crossed with another heterozygous (tt) plant. (underline important information and write the alleles.)

probabilities

genotypes %	phenotypes %
50% tt
25% tt	25% short

punnett square

parents →	t	t
t

1. a homozygous dominant tall plant (tt) is crossed with a homozygous recessive short (tt) plant. what are the genotypes and phenotype possibilities for the offspring?

probabilities

genotypes %	phenotypes %

punnett square

parents →

in pea plants purple flowers are dominant, white flowers are recessive. use the allele f to represent your genotypes.

1. if two white flowered plants are crossed, what percentage of their offspring will be white flowered?

tt × tt
probabilities

genotypes %	phenotypes %

punnett square

parents →	t	t
t

Explanation:

Step1: Analyze the cross for question 2

The cross is \( TT\times tt \). The \( TT \) parent can only contribute \( T \) alleles, and the \( tt \) parent can only contribute \( t \) alleles.

Step2: Fill in the Punnett square

Parents →	\( T \)	\( T \)
\( t \)	\( Tt \)	\( Tt \)

Step3: Calculate genotypes and phenotypes

All offspring have the genotype \( Tt \). Since \( T \) (tall) is dominant over \( t \) (short), all offspring will have the tall phenotype.

For question 3:

Step1: Analyze the cross \( ff\times ff \)

Both parents can only contribute \( f \) alleles.

Step2: Fill in the Punnett square

Parents →	\( f \)	\( f \)
\( f \)	\( ff \)	\( ff \)

Step3: Calculate genotypes and phenotypes

All offspring have the genotype \( ff \). Since white flowers are recessive (\( f \)), all offspring will have white flowers.

Answer:

2.

Genotypes %	Phenotypes %

3.

Genotypes %	Phenotypes %