Blended and both-showing traits

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. 1.

   Ari reads a Punnett square for a red-flowered snapdragon crossed with a white-flowered one. What color is the flower in the top-left box?

   • Red and white patches, because both alleles show
   • White, because the side parent has white flowers
   • Pink, from one red and one white allele
   • Red, because the red allele hides the white allele
2. 2.

   Bo reads a square for two pink snapdragons. What color is the flower in the empty bottom-right box?

   • Red, because the top parent passes on R
   • Red and white patches, because both alleles show
   • Pink, because both parents are pink
   • White, from two white alleles
3. 3.

   Esme reads a model square for a roan parent crossed with a red parent. Which genotype fills the top-right box?

   • W (one white allele)
   • RR (two red alleles)
   • WW (two white alleles)
   • RW (one red and one white allele)

4. Read this first

   A snapdragon cross (model)

   plant	genotype	flower color
   red parent	RR	red
   white parent	WW	white
   offspring	RW	pink

5. 4.

   Jun reads a snapdragon cross card. Which pattern does it show?

   • Complete dominance: one allele hides the other allele
   • Blending: the alleles mix and stay mixed
   • Incomplete dominance: the offspring look in between the parents
   • Codominance: both alleles show side by side

6. A cattle cross (model)

   animal	genotype	coat
   red parent	RR	all red hairs
   white parent	WW	all white hairs
   offspring	RW	red hairs and white hairs together

7. 5.

   Kira reads a model cattle cross card. Which word describes the offspring coat?

   • Complete dominance: the red allele hides the white allele
   • Segregation: the alleles split into two groups
   • Codominance: both alleles show at the same time
   • Incomplete dominance: one mixed color between the parents

8. A pea flower cross (model)

   plant	genotype	flower color
   parent one	VV	violet
   parent two	vv	white
   offspring	Vv	violet

9. 6.

   Luz reads a pea cross card. Which pattern does it show?

   • Complete dominance: V hides v, so Vv looks violet
   • Codominance: Vv shows violet and white patches
   • Incomplete dominance: Vv looks in between the parents
   • Blending: the colors mix, so Vv should look pale

10. Three cattle coats (model)

    genotype	coat	hairs
    RR	red coat	all red hairs
    RW	roan coat	red hairs and white hairs mixed
    WW	white coat	all white hairs

11. 7.

    Milo reads a model coat card. A calf has genotype RW. What do its hairs look like?

    • Red hairs alone, because R hides W
    • White hairs alone, because W hides R
    • Pink hairs, a blend of red and white
    • Red hairs and white hairs, mixed together

12. Three snapdragon plants (model)

    plant	flower color
    X	red
    Y	pink
    Z	white

13. 8.

    Pia reads a snapdragon card. Plant Y has pink flowers. Which genotype does it have?

    • R (a single red allele)
    • RR (two red alleles)
    • RW (one red and one white allele)
    • WW (two white alleles)
15. 9.

    Ren reads the filled square for two pink snapdragons. Which list matches the four boxes?

    • 3 red or pink, 1 white
    • 1 red, 2 pink, 1 white
    • 4 pink, since both parents are pink
    • 2 red, 2 white
16. 10.

    Zee reads the filled square for two pink snapdragons. It shows a white flower. Why is that possible?

    Use the picture in question 9.

    • Each pink parent carries a white allele and can pass it on
    • The red allele fades to white in some boxes
    • Pink parents give pink offspring, so the white box is an error
    • The white allele was lost, so the square must be wrong