Basic Punnett squares

What ratio of the offspring from the cross shown will be homozygous recessive for the  trait of tallness? 

• 0 in 4
• 1 in 4
• 2 in 4
• 4 in 4

Tags

NGSS.HS-LS3-1

Which of the following genotypes is homozygous dominant?

• A
• Aa
• AA
• aa

Which of the following genotypes is heterozygous?

• Bb
• BB
• bb
• B

In a heterozygous genotype, the ___________ allele takes over in the phenotype.

• recessive
• dominant
• lower case letter
• both 

What you see, or the physical appearance.

• Genotype
• Phenotype
• Homozygous
• Heterozygous

Tags

NGSS.HS-LS3-1

T - tall and t = short
In the punnett square below, what belongs in the missing square

• tt
• Tt
• Bb
• TT

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

B = brown eyes
b = blue eyes
What is true about these two brothers that have brown eyes?
One has genotype BB the other Bb.

• they have same phenotype and genotype
• they have different genotypes and phenotypes
• they have same phenotype but different genotypes
• they have same genotype but different phenotypes

Tags

NGSS.HS-LS3-1

Which of the following is homozygous recessive?

• Tt
• tt
• TT
• T

In pea plants, the tall allele is dominant to the short allele. What key would demonstrate this?

• Tall = T
  Short = S
• Tall = T
  Short = t
• Tall = t
  Short = T
• Tall = TT
  Short = tt

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

A heterozygous long-tusked elephant is crossed with a homozygous recessive short-tusked elephant. What is the probability of the offspring having short tusks?

• 0%
• 25%
• 50%
• 75%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2