Punnett squares/ Heredity/ and genes

Why do we use Punnett Squares?

• To see what DNA the organism has.

• to visually see and find the possible genotypes and phenotypes of offspring resulting from a cross between two individuals

• to study and understand observable characteristics of an organism

• To see if its a Boy or Girl

Which of the following represents a homozygous genotype? There are two answers

• AA

• Aa

• aa

• ABa

In a Punnett square, what does each box represent? (Hint Comes from Mom and Dad)

• A possible genotype combination of the parents

• A different allele

• A different trait

• A possible phenotype

What is the phenotype of an organism with the genotype "Bb"?

(Hint: Is the capital letter dominant or recessive? )

• It will have no phenotype.

• It will express the recessive trait.

• The phenotype cannot be determined with this information.

• It will express the dominant trait.

True or false: In a Punnett square, the parents' genotypes are placed on the sides, and their possible offspring combinations are inside the grid.

• True

• False

True or false: A recessive trait will only be expressed if the organism has two copies of the recessive allele. ( aa, bb)

• true

• false

Match the terms with their definitions.

• Phenotype

• An organism's physical appearance or observable traits.

• Homozygous

• Two identical alleles for a trait.

• Heterozygous

• Two different alleles for a trait.

• Genotype

• The genetic makeup of an organism.

Having a Widow's Peak is dominant (W) over not having one (w). If parent A (WW) and parent B (ww) have a child, what is the likelihood that--

• 100%

• The child will have a widow's peak

• Ww

• The child will not have a widow's peak

• 0%

• The genotype of these children

T - tall and t = short. In the Punnett square below, what belongs in the missing square (a)  

• tt
• Tt
• Bb
• TT

Complete the punnett square

a

b

c

d

T t bottom row

T T

t t

T t top row