Meiosis and Punnett Squares

In tomato plants, the tall vine allele (T) is dominant to the short vine allele (t). Two tomato plants are crossed. Among the offspring plants grow from seed, 45% have tall vines and 55% have short vines. What are the most likely genotypes of the parent plants?

• TT and tt

• Tt and Tt

• Tt and tt

• tt and tt

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

In fish of a certain species, some individuals have mouths that open to the right and some individuals have mouths that open to the left. The direction of the mouth opening is a genetic trait controlled by a single gene. The allele for a right-opening mouth (R) is dominant to the allele for a left-opening mouth (r). If two fish heterozygous for the mouth trait are crossed, what is the expected ratio of phenotypes in the offspring?

• 1 right-opening mouth: 3 left-opening mouth

• 2 right-opening mouth: 2 left-opening mouth

• 3 right-opening mouth: 1 left-opening mouth

• 4 right-opening mouth: 0 left-opening mouth

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-3

NGSS.HS-LS4-3

Garden pea plants can have yellow seeds or green seeds. In a pea plant that is heterozygous for seed color, the allele for yellow seeds masks the effects of the allele for green seeds. Which of the following terms best describes the allele for yellow seeds?

• codominant

• dominant

• recessive

• sex-linked

In mussles, the allele for brown coloring (B) is dominant, and the allele for blue coloring (b) is recessive. For which parental genotypes are 100% of the offspring expected to be blue?

• Bb x Bb

• BB x bb

• bb x bb

• BB x BB

Tags

NGSS.HS-LS3-1

Which of the following cell types is formed by meiosis?

• muscle cells

• sperm cells

• skin cells

• blood cells

Tags

NGSS.HS-LS3-2

Which of the following statements correctly describes meiosis?

• Cells divide only once during meiosis

• Meiosis does not occur in reproductive cells

• The cells produced at the end of meiosis are genetically identical to the parent cells

• The cells produced at the end of meiosis contain half the number of chromosomes as the parent cell.

Which of the following sequences represents chromosome number during fertilization?

• n + n = 2n

• 2n --> n + n

• n --> n

• 2n --> 2n

Tags

NGSS.HS-LS3-2

In horses, the gene for white hair (W) is dominant to the gene for non-white hair (w). A horse with genotype (WW) was crossed with genotype (ww). What fraction of the offspring should be expected to have white hair?

• none

• one half

• three quarters

• all

Tags

NGSS.HS-LS3-1

The distribution of chromosomes in one type of cell division is shown in the diagram above.

Which process and type of resulting cells are represented in the diagram?

• mitosis, which produces gametes

• mitosis, which produces body cells

• meiosis, which produces gametes

• meiosis, which produces body cells

Tags

NGSS.HS-LS3-2

NGSS.HS-LS1-4

The diagram above shows homologous chromosomes during prophase I of meiosis. Which of the following correctly describes the process being illustrated?

• mutation in which the DNA content of the gene is altered

• segregation of sister chromatids

• condensation and segregation of alleles

• crossing-over in which alleles are exchanged