Meiosis and Punnett Squares

Which of the following stages of meiosis involves the pairing of homologous chromosomes?

• Metaphase I

• Prophase I

• Anaphase II

• Telophase I

During which stage of meiosis does crossing over occur?

• Metaphase II

• Anaphase I

• Prophase I

• Telophase II

What is the main purpose of crossing over during meiosis?

• To increase genetic diversity

• To reduce chromosome number

• To replicate DNA

• To separate sister chromatids

Calculate the genotype ratio for a monohybrid cross between two heterozygous individuals (Aa x Aa).

• 2:1

• 3:1

• 9:3:3:1

• 1:1

Complete the punnett square

a

b

c

d

T T

T t top row

t t

T t bottom row

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

According to this Punnett square​ (a)   of the offspring will be homozygous dominant, ​ (b)   Of the offspring will be heterozygous, and the remaining 25% will be homozygous ​ (c)   . As for the phenotypes, ​ (d)   of the flowers will be ​ (e)   .

• 25%

• 50%

• recessive

• 75%

• pink

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

According to this Punnett square ​ (a)   Of the offspring will be homozygous dominant, ​ (b)   Of the offspring will be heterozygous, and the remaining 25% will homozygous ​ (c)   . As for the phenotypes, ​ (d)   Of the flowers will be ​ (e)   .

• 25%

• 50%

• recessive

• 75%

• pink

• 100%

• White

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Fill in the missing genotypes

a

b

bB

BB

Bb

bb

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

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

• tt

• Tt

• Bb

• TT

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

What is the probability of a purple-horned unicorn if a heterozygous pink-horned unicorn is crossed with a heterozygous pink-horned unicorn? (a)  

• 0%

• 25%

• 50%

• 75%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3