9th grade Multiple alleles: ABO blood types worksheet

Multiple alleles: ABO blood types

Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

1. 1.

   Ari crosses model parents with genotypes IAi and IBi. What is the chance that one offspring is type O?

   • 3 in 4, since 3 boxes carry an i
   • 1 in 2, since both parents carry an i
   • 1 in 16, since 1 in 4 times 1 in 4
   • 1 in 4, since only ii is type O
2. 2.

   Bo crosses model parents with genotypes IAi and IAIB. What is the chance that one offspring is type O?

   • 1 in 4, since one parent carries an i
   • 1 in 2, since one parent is IAi
   • 2 in 4, since two boxes carry an i
   • 0 in 4, since no box is ii
3. 3.

   Esme crosses model plants with genotypes Pw and Yw. What is the chance that one offspring has yellow flowers?

   • 1 in 3, since 1 of 3 colors is yellow
   • 1 in 2, since PY and Yw both carry Y
   • 3 in 4, since only ww is not yellow
   • 1 in 4, since only Yw is yellow

4. Read this first

   Table

   Model plant cross card (model data, not a real plant), 3 rows. Columns: item, note. Row 1: parent 1, Pw. Row 2: parent 2, ?. Row 3: offspring colors, purple, yellow and white.

5. 4.

   Luz reads a model plant cross card. Which genotype could parent 2 be?

   • ww (two w alleles)
   • PY (one P allele, one Y allele)
   • YY (two Y alleles)
   • Yw (one Y allele, one w allele)

6. Notebook

   Notes on a model cross (classmate's notebook), 4 lines. Columns: line, entry. Line 1: Each parent passes on one of its two alleles, chosen at random. Line 2: The four boxes are IAIB, IBi, IAi and ii. Line 3: IAIB shows both type A and type B, so it is type AB. Line 4: The four genotypes are in the ratio 1 : 2 : 1.

7. 5.

   Tala reads a classmate's notebook about a model IAi × IBi cross. Which line has the mistake?

   • Line 4: the four genotypes are in the ratio 1 : 1 : 1 : 1
   • Line 2: the ii box should be left out
   • Line 3: IAIB should show a blend of type A and type B
   • Line 1: a parent should pass on both of its alleles

8. Notebook

   Notes on the ABO alleles (classmate's notebook), 4 lines. Columns: line, entry. Line 1: The ABO gene has three alleles in the population: IA, IB and i. Line 2: A genotype is a pair of alleles, one from each parent. Line 3: So one genotype can hold IA, IB and i together. Line 4: Six genotypes are possible: IAIA, IAi, IBIB, IBi, IAIB and ii.

9. 6.

   Zee reads a classmate's notebook about the ABO alleles. Which line has the mistake?

   • Line 1: the gene has two alleles in the population
   • Line 4: just four genotypes are possible
   • Line 2: a genotype should hold three alleles
   • Line 3: one genotype holds two alleles, not three

10. Notebook

    Notes on a model plant (classmate's notebook), 4 lines. Columns: line, entry. Line 1: In the model plant, P is dominant to Y and w, and Y is dominant to w. Line 2: A PY plant has purple and yellow flowers together. Line 3: A Yw plant has yellow flowers. Line 4: A ww plant has white flowers.

11. 7.

    Noah reads a classmate's notebook about a model plant with three alleles. Which line has the mistake?

    • Line 2: a PY plant has purple flowers
    • Line 4: a ww plant should have yellow flowers
    • Line 3: a Yw plant should have white flowers
    • Line 1: Y should be dominant to P
12. 8.

    Pia claims that two model parents with type A cannot have a type O offspring. Do you agree?

    • Yes, because type A parents carry just IA alleles
    • Yes, because the i allele is lost once IA hides it
    • No, because two IAi parents can each pass on i, giving ii
    • No, because IAi is type O, and IAIA is type A

13. Allele card (model)

    item	note
    IA	gives type A
    IB	gives type B
    IA and IB	codominant

14. 9.

    Ren claims that an offspring with genotype IAIB shows a blend of type A and type B. Do you agree?

    • Yes, because two different alleles give an in-between look
    • No, because IA hides IB, so just type A shows
    • Yes, because IAIB is halfway between type A and type B
    • No, because IA and IB are codominant, so both types show

15. Table

    ABO alleles (model), 2 rows. Columns: item, note. Row 1: alleles in the population, IA, IB and i. Row 2: one genotype, a pair of alleles.

16. 10.

    Milo claims that three alleles mean three genotypes. Do you agree?

    • Yes, because each allele makes one genotype
    • No, because four types need four genotypes
    • No, because the pairs of alleles make 6 genotypes
    • No, because one genotype holds the three alleles together