Mendel's laws of segregation and independent assortment
Grade 9 Science Worksheet - Building Confidence
Circle the best answer.
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Table
A pea cross in four boxes (model), 4 rows. Columns: box, plants shown. Row 1: W, the two true-breeding parent plants, one with violet flowers and one with white flowers. Row 2: X, the offspring of those two parent plants. Row 3: Y, the offspring of two box X plants crossed together. Row 4: Z, the offspring of two box Y plants crossed together.
Ari labels a pea cross with boxes W, X, Y and Z. Which box shows the F2 generation?
- Box Y: the offspring of two box X plants
- Box Z: the offspring of two box Y plants
- Box W: the two plants crossed first
- Box X: the first offspring of the parents
Two pea lines (model)
plant line offspring when crossed with itself violet-flowered line violet flowers in each generation white-flowered line white flowers in each generation Bo reads that Mendel started with true-breeding pea plants. What does true-breeding mean?
- Crossed with themselves, they always give offspring that look like them
- They carry a violet and a white allele, so they give both colors
- They are a mix of two lines, so their flowers show a pale blend
- They have two recessive alleles, so they show the recessive trait
Jun fills a Punnett square for pea seed shape. Which genotype goes in the blank box?
- RR (two round alleles)
- Rr (one round, one wrinkled allele)
- rr (two wrinkled alleles)
- r (one wrinkled allele)
Kira fills a Punnett square for pea plant height. Which genotype goes in the blank box?
- Tt (one tall, one dwarf allele)
- T (one tall allele)
- tt (two dwarf alleles)
- TT (two tall alleles)
Luz reads a filled Punnett square for seed color. How many of the four boxes show a plant with yellow seeds?
- 3 boxes: YY, Yy and Yy
- 2 boxes
- 4 boxes, since both parents have a Y
- 1 box
Milo sees each box of the grid take one allele from each parent. Which idea explains this?
- Independent assortment: different genes are passed on separately
- Segregation: the two alleles of a gene separate
- Dominance: one allele hides the other allele
- Blending: the two alleles mix into one allele
One plant, two genes (model)
gene plant's alleles where the gene sits flower color Vv one chromosome plant height Tt a different chromosome Noah reads a card about two genes on different chromosomes. Which idea says they are passed on separately?
- Segregation: the two alleles of a gene separate
- Independent assortment: the two genes are passed on separately
- Dominance: one gene hides the other gene
- Blending: the two genes mix into one trait
Flower color across two generations (model)
generation plants flower color P true-breeding VV and vv plants violet and white F1 all Vv all violet Pia reads that every F1 plant is Vv and has violet flowers. Which idea explains the violet color?
- Segregation: the Vv plant passes on one of its two alleles
- Independent assortment: V and v are passed on separately
- Dominance: V hides v in a Vv plant
- Blending: V and v mix into a pale violet
Mendel's real counts, flower color (real data: Mendel)
generation what the plants showed F1 100 percent violet F2 705 violet and 224 white Ren reads Mendel's flower-color counts. How many F2 plants had white flowers?
- 0 plants, because white was lost in the F1
- 705 plants
- 224 plants, the white-flowered ones
- 929 plants
Mendel's real counts, seed color (real data: Mendel)
generation what the plants showed F1 100 percent yellow F2 6,022 yellow and 2,001 green Zee adds up Mendel's F2 seed-color counts. How many seeds did Mendel count in the F2?
- 6,022 seeds
- 4,021 seeds
- 8,023 seeds
- 2,001 seeds