Genetics and Punnett Squares

A Punnett square is a ​ (a)   that allows you to easily determine the expected ​ (b)   of different ​ (c)   in the ​ (d)   of two parents. An example of a Punnett square for pea plants is shown here. In this example, both parents are ​ (e)   for flower color (Pp).

• chart
• percentage
• genotypes
• offspring
• heterozygous

In the cross shown above, you can see that ​ (a)   (25 percent) has the genotype PP, one out of four (25 percent) has the genotype pp, and ​ (b)   (50 percent) have the genotype Pp. These percentages of genotypes are what you would expect in any cross between ​ (c)   Of course, when just four offspring are produced, the actual percentages of genotypes may vary by chance from the expected percentages. However, if you considered hundreds of such crosses and thousands of offspring, you would get very close to the expected results, just like tossing a coin.

• one out of four offspring
• two out of four
• two heterozygous parents.

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

An organism's genotype describes its __________.

• genetic makeup

• physical appearance

An organism's phenotype describes its __________.

• genetic makeup

• physical appearance

B = brown fur b = white fur

In the punnett square, what is the probability for white fur?

• 0%

• 25%

• 50%

• 75%

If you cross breed Spider 3 and Spider 4, what percent of spider will have bristled legs?

• 100%

• 75%

• 50%

• 25%

Which of the following is homozygous recessive?

• rr
• AA
• TT
• Ff

Fill in the Yellow Box

• AA

• Aa

• aa

Tags

NGSS.MS-LS3-2

What is the probability of obtaining a heterozygous genotype from a cross between two heterozygous parents?

• 75%

• 50%

• 25%

• 0%

Tags

NGSS.HS-LS3-3

Which of the following represents a homozygous dominant genotype?

• aa

• BB

• Cc

• dd